Multi attribute decision making through COPRAS on tensile properties of hybrid fiber metal laminate sandwich structures for aerospace and automotive industries

Abstract

Fiber metal laminates (FMLs) are made by sandwiching a fiber-reinforced composite between thin layers of metal. FMLs are modern materials utilized in the manufacture of automobiles and aircraft because of their improved mechanical behavior compared to conventional metallic alloys. In the current study, different fabrics, that is, jute (J), glass (G), carbon (C), basalt (B), and aramid (A) were used as reinforcing components for composites that were sandwiched between two aluminum (Al) alloy sheets as a metal component in the proposed FMLs. The effect of hybridizing J-reinforced composite with different declared fabrics on the tensile response of the designed FMLs was experimentally investigated. The proposed FMLs were created using manual lay-up and compression casting techniques. Complex proportional assessment (COPRAS) was adapted to find the best FMLs structure that achieved the optimum tensile properties. The Al/2C/4J/2C/Al and Al/8J/Al structures were ranked first and last, respectively, based on COPRAS results.

Keywords

Tensile properties fiber metal laminates hybrid fabrics tensile failure modes COPRAS natural fiber

Highlights

• The designed fiber metal laminates (FMLs) were first prepared using manual lay-up and compression casting techniques.

• Tensile tests were carried out on the designed FMLs according to the ASTM D3039 standard and the failed specimens were examined using optical and microscopic images.

• Tensile properties were determined and discussed. Furthermore, complex proportional assessment (COPRAS) was applied to find the best FMLs structure.

• All designed structures were ranked according to their best tensile properties. Al/2C/4J/2C/Al and Al/8J/Al structures were ranked first and last, respectively, based on COPRAS results.

Introduction

Fiber metal laminates (FMLs) are a class of hybrid materials constructed of alternatively stacked metal and fiber-reinforced composite layers or fiber-reinforced composite layers sandwiched between thin layers of metal.^1–4 FMLs are composed of high-performance materials extensively used in the automobile and aircraft industries.⁵ Natural fibers have been progressively used as reinforcing materials in polymer composites in recent years due to their low cost, availability, good thermal and acoustic protection, brilliant specific mechanical properties, renewability, and ability to be recycled.^6–9 These benefits make natural fibers an attractive alternative to synthetic fibers for a variety of uses, either entirely or partially. The contemporary trend of replacing synthetic fibers in polymer composites with natural fibers can also be extended to FMLs. Many investigators in the literature have studied the mechanical properties of FMLs based on different types of natural fibers.^10–15

Despite their appeal, natural fibers have a few drawbacks over synthetic fibers, including a high degree of inconsistency, poor moisture and impact resistance. By keeping the benefits of natural fibers while reducing some of their drawbacks, hybrid structures can be used.^16–19 Because they can be readily customized to provide greater characteristics that are impossible to achieve with a single fiber reinforced composite, hybrid composites are becoming increasingly popular.²⁰ By combining the weaker fiber with a stronger one, hybridization can improve the mechanical, physical, and chemical properties of composites, consequently avoiding their disadvantages. As a result, the hybridization procedure may be used as a tactic to increase the use of various composites in various industrial applications.^21–23

Although many researchers have looked at FMLs made of natural fibers, as stated above, there have been fewer studies done on FMLs made of natural/synthetic hybrid fibers. The tensile, compression, and flexural properties of natural/synthesis based FMLs were studied by Mohammed et al.²⁴ Flax (F), kenaf (K), carbon (C) fibers, aluminum (Al) alloy 2024 and epoxy were used as constituent materials. (C)/(F) fibers reinforced epoxy with (Al) sheets named (CAFRALL) and (C)/(K) fibers reinforced epoxy with (Al) sheets named (CAKRALL) were fabricated. The experimental results revealed that CAKRALL has the highest elasticity modulus of 4.4 GPa and exhibits better tensile and compressive strengths than CAFRALL, with an improvement of 14.8 and 20.4%, respectively. While CAKRALL has 33.7% lower flexural strength than CAFRALL. Feng et al.²⁵ found that the tensile strength of (K)/glass (G) FMLs is increased by the addition of G-fiber. When G-fabric is substituted for the center K-layers, the greatest fatigue resistance can be obtained.

Azghan and Farsani²⁶ and Azghan et al.²⁷ investigated how stacking patterns and heat cycling affected the flexural and tensile properties of FMLs. Al alloy sheets were employed for the skin, while the composites section consisted of four layers of basalt (B) fiber and/or G-fiber stacked in five different ways. The heat cycle time for FML samples was about 6 min for temperature cycles from 25 to 115°C. The samples' flexural and tensile characteristics were assessed after 55 heat cycles and compared with those of unexposed samples. The results of this investigation demonstrated that the flexural modulus is the highest for (B) fiber-based FML, the lowest for (G) fiber-based FML, and intermediate for B/G FMLs. FMLs with four layers of B-fiber display the highest levels of tensile strength, modulus, and energy absorption. The asymmetrically stacked sample with B and G-fibers, on the other hand, has the lowest strength and fracture energy. On the occasion of the samples exposed to thermal cycling, the highest and lowest thermal stabilities were detected, respectively, in B-fibers samples and asymmetrically stacked samples.

The effects of incorporating metal plates (Al2024-T3 and stainless steel 316L) into B/K fiber reinforced epoxy composites on Charpy impact behavior were investigated by Arpatappeh et al.²⁸ Results indicated that FMLs with Al-plates exhibit higher impact energy than those with steel plates. Zareei et al.²⁹ explored the tensile and interlaminar shear properties of environmentally-friendly FMLs with J-B fabrics as hybrid reinforcements, Al2024-T6 as a coating, and an epoxy as a matrix. Four hybrid structures, i.e., Al/2J/2B/2J/Al, Al/2B/2J/2B/Al, Al/J/B/J/B/J/B/Al, and Al/B/J/B/J/B/J/Al, were fabricated and tested. The outcomes displayed that J-fiber sandwiched by B-fiber gives the maximum tensile strength, interlaminar shear strength (ILSS), and modulus of elasticity. Microstructural analyses showed that the B-fiber has a powerful bond with the Al plies, whereas the J-fiber has a weak one. Additionally, it was discovered that the absence of diffusion leads to the existence of empty spaces between J-fibrils.

Abd El-baky et al.³⁰ investigated the influence of stacking sequences and relative fiber amounts on novel hybrid FMLs constructed on Al1050 and J-G fibers/epoxy composites. Results showed that hybridization may enhance the tensile and flexural characteristics of FMLs made from J-fabric. When G/epoxy laminas are substituted for partial J/epoxy laminas, the flexural strength of FMLs is increased. It is understood that adding high-strength fibers to a composite core results in a material with greater tensile properties but lower flexural resistance.

In addition to the mechanical properties of the designed material, selecting the best structure, i.e., making a decision about the best structure, is a critical issue to be concerned with. Multi-attribute decision-making (MADM) is a well-known branch of decision-making that deals with decision complications through a number of qualitative and quantitative criteria. A limited number of choices are ranked and chosen based on specified qualities. The multiple attribute-based decision issues should be solved using one of the many ways; in addition, the inconsistency between MADM method selection and the availability of the various MADM problem-solving strategies exists. These inconsistencies may result from different weighting methods, methods for choosing the "best" solution, objective scaling, and the addition of more parameters. Many scholarships use MADM methods, like the analytical hierarchy process (AHP), method of order preference similarity to the ideal solution (TOPSIS), preference ranking organization method for enrichment evaluations (PROMETHEE), and complex proportional assessment (COPRAS), to find the best option, which achieves the best response.^31–36

COPRAS as one of the multi-attribute decision-making (MADM) methods, was employed in the current work to identify the stacking sequence that has the optimal tensile properties due to its ease compared with other multi-criteria decision-making methods. It is able to show a utility degree. On top of that, as reported by Podvezko³⁷ and Zavadskas et al.³⁸ COPRAS method provides extra accuracy in calculating alternative rankings as the assessment of the maximum and minimum criteria is done independently.^39,40 The COPRAS method as the ranking method is a suitable strategy to prepare the information in a sensible and effective way. The strategy used by the COPRAS can process the criterion information from distinctive points based on a complex proportional calculation, which contains more accurate information compared with other strategies.⁴¹ More details about COPRAS can be found in the literature.^42,43

The COPRAS method has received enough attention from decision-makers. The target of these methods is to provide a convenient way for decision makers to select desirable alternatives. Among these methods, COPRAS has recently attracted much attention. As a compromising method, the COPRAS method determines a solution based on the ratio between the ideal solution and the worst-ideal solution. Unlike other MADM methods, the COPRAS method relies on a stepwise ranking and utilizes both significance and utility degrees to make a rational selection. The COPRAS-based technique demonstrates less estimation time, is extremely straight-forward and high plausibility of graphical elucidation as compared to other methods. The advantages of COPRAS method include: (a) Based on proportional assessments, it makes decisions based on benefit and cost; (b) it makes it easy to ascertain the gap between each alternative and the optimal one via the utility degrees.⁴⁴ Also, the primary benefit of this technique is its ease of use, effectiveness, and friendliness.⁴⁵ On the other hand, COPRAS may be less stable in comparison with the TOPSIS method in the case of data variation. Also, the results may be sensitive to a slight variation of data, and the dedicated ranks may be different from those obtained through other methods.⁴⁶

Due to its low cost, lightweight, and availability, jute (J) is considered a promising natural fiber.^47–50 In spite of these advantages, J-fiber has some drawbacks and thus needs to be hybridized with other strong fibers. Based on the above-mentioned literature survey, quite little work has been undertaken with a view to investigating the properties of jute (J)-reinforced polymer FMLs and their hybrids. The current work aims to study the tensile properties of FMLs made of (J)/synthetic hybrid fibers. The designed FMLs were created using hand lay-up and compression casting methods. The proposed FMLs utilized epoxy with various fabrics in the composite component, including (J), glass (G), carbon (C), basalt (B), and aramid (A), sandwiched between two sheets of aluminum alloy (Al1050) with a thickness of 0.5 mm. The impact of hybridizing the declared fabrics with J-fabric/epoxy composites on the tensile response of the designed FMLs was evaluated. Also, the authors tried to obtain the FML structure, which achieves the best response, i.e., the optimum tensile properties. For this goal, a multi-attribute decision making (MADM) method called complex proportional assessment (COPRAS) was used. Since hybridization may be used as a tactic to increase the use of various composites in various industrial applications, the authors in this work performed a comparative study using different types of fabrics in order to overcome the drawbacks of J-fabric.

Material and methods

Materials

In this study, the skin layers of the developed FMLs were made of Al1050 in the form of sheets with a thickness of 0.5 mm. Al1050 is made up of the following chemical elements: Al (99.5%), Cu (0.05%), Fe (0.4%), Mn (0.05%), Mg (0.05%), Si (0.25%), Ti (0.03%), V (0.05%), and Zn (0.05%). The popular Al1050 has excellent corrosion resistance, a highly reflective finish, great ductility, and moderate strength.⁵¹ The developed FMLs were made using 0°/90° plain weave jute (J), E-glass (G), carbon (C), basalt (B), and aramid (A) fabrics with a constant areal density of 200 g/m². The reason for selecting woven materials is that they are simple to produce, have balanced properties, and have the best level of robustness to plane shear,⁵² Table 1 displays the characteristics of the utilized Al1050 and reinforcements. Kemapoxy 150 RGL was chosen as a matrix. Kemapoxy 150 RGL has been successfully applied in the literature^53–60 because it is distinguished by a strong resilience to chemical and mechanical properties. Table 2 shows the physical and mechanical properties of Kemapoxy 150 RGL given by the supplier.

Table 1.

Mechanical properties of Al alloy and reinforcements given by the manufacturers.

Material	Producer	Density (g/cm³)	Young's modulus (GPa)	Tensile strength (MPa)	Elongation (%)	Poisson’s ratio	Shear modulus (GPa)
Al1050	Metallurgical industries co. Ltd. Egypt	2.71	71	100	120	0.33	51
Jute	Hangzhou Zhong Xing Cotton and jute co. Ltd. China	1.35	17	470	1.5-1.8	0.38	7.24
E-glass	Hebei Yuniu fiber glass manufacturing co. Ltd. China	2.5	76	3400	1.8-3.2	0.22	33
Aramid	Yixing Zhongfu carbon fiber products co., Ltd. China	1.4	67	3000-3150	2.5-3.6	0.36	16.2
Carbon	Yixing Yitai carbon fiber weaving co. Ltd. China	1.9	260	4200-4800	1.75-1.95	0.279	110
Basalt	Quanzhou basalt manufacturing co. Ltd. China	2.8	79	3000-4840	3.15	0.2	21.70

Table 2.

Physical and mechanical properties of Kemapoxy 150 RGL given by the supplier.

Property	Kemapoxy 150 RGL
Color	Transparent
Density, g/cm³	1.1
Young’s modulus, GPa	1.2
Poisson’s ratio	0.35
Elongation (%)	2.2-2.9
Tensile strength, kg/cm²	150-250
Compressive strength, kg/cm²	500-1000
Flexural strength, kg/cm²	200-400
Epoxy (bisphenol A-based) resin viscosity, MPa.s	1049
Hardener (cycloaliphatic amine) viscosity, MPa.s	254
Mixture viscosity, MPa.s	162
Glass transition temperature (T_g)	90°C
Solid content by weight, %	100
Curing conditions at 25°C	- Initial setting time: 8 h
	- Final setting time: 24 h
	- Full hardness time: 7 days

Preparation of FMLs

FMLs were created using hand lay-up and compression casting, which have been used by many researchers,^51,61,62 due to simplicity and minimum infrastructural requirements. Al-sheets underwent mechanical and chemical treatments to ensure good adhesion with polymer composites. Al-sheets go through a mechanical process that includes acetone rinsing, smooth abrading with # 400 grit sandpaper, tap water rinsing to remove the fine chips produced from the smooth abrading and the residual acetone excess, and oven drying.^61,63

After that, HCl at 11% volumetric concentration was added to the mechanically treated Al-sheets to be acid washed to elevate its surface roughness. At room temperature, acid etching was carried out for 30 min. All linens were dried after being rinsed with tap water.⁶⁴ Al-sheets were subsequently soaked in a 5 wt % NaOH solution for 5 min at 70°C. The oxidized Al-sheets were dried in an oven to stabilize the oxide coating after being rinsed with tap water to remove any leftover oxide.^51,59 The surface profile of Al-sheets before and after treatment is shown in Figure 1. As stated by Golru et al.,⁶⁵ surface treatment increases the surface roughness of Al-sheets. Increasing the surface roughness helps to introduce a good bond between Al-sheets and fabrics. The same results were obtained by Megahed et al.,⁴ Abd El-baky et al.,^23,60 and Alshahrani et al.⁶⁶.

Figure 1.

Al-sheet (a) before and (b) after mechanical and chemical treatments.

After that, the epoxy and its hardener were combined in a ratio of 2:1, respectively, based on the data sheet supplied by the producer. Then, a homogeneous layer of the mixture was applied over the treated Al-sheets and woven fabric layers. In this work, eight layers of fabrics were used for each designed structure, which determined the specimen thickness. The designed sequences are shown in Figure 2. For 24 h at room temperature, the constructed FMLs were held under 2.5 bars of pressure to cure and remove the voids and excess matrix. Pressurizing results in reduction of voids and removal of excess resin. Residual voids were minimal and insignificant. This agrees with the data provided by Moussavi-Torshizi et al.⁶⁷. The mechanical tests were conducted after 21 days to ensure maximum strength and the full recovery of the specimens. No residual tension is created in FMLs because the cure procedure was carried out at room temperature.^61,68

Figure 2.

Stacking sequences for the designed FMLs.

Tensile test

Tensile testing is a destructive, essential test in material science that provides fundamental design parameters such as the ultimate tensile strength ( $σ_{u l t}$ ), modulus of elasticity ( $E_{a p p}$ ), toughness modulus ( $U_{T}$ ), and ductility of the material. It is an essential step of the industrial process for product qualification purposes.⁶⁹

The developed FMLs underwent a tensile test on a universal testing machine (Jinan WDW with 100 kN capacity) at a 2 mm/min strain rate. To guarantee constancy, three specimens for each FML were tested. The typical outcome was noted. According to ASTM D3039 the manufactured FMLs were sliced into strips with a size of 250 × 25 mm² using a rotating band saw with a narrow pitch to prevent damage (delamination) throughout the cutting process. This cutting method has been used in many previous works.^70–72 Each test specimen's gripping area was epoxy-glued to four rectangular Al-tabs. Refereeing to Khashaba,⁷⁰ Kumar et al.,⁷³ Selmy et al.,⁷⁴ and Ali et al.,⁷⁵ these tabs help in transferring the pressure from the machine to the specimen, lessening the stress concentration given by the grips, and protecting the specimen from crushing between the testing equipment's grips. Stress-strain curves (strain values calculated based on the recorded displacement of the test machine's actuator) were produced for each specimen in order to calculate the tensile properties, which include the ultimate tensile strength ( $σ_{u l t}$ ), and the apparent tensile modulus ( $E_{a p p}$ ) were all assessed using the relations presented below:

σ_{u l t} = \frac{P_{\max}}{b h}

(1)

E_{a p p} = \frac{∆ σ_{t}}{∆ ε_{L}}

(2)

where

P_{\max}

is the maximum applied load, ∆𝜎_𝑡/∆ɛ_𝐿 means the slope of the stress-strain curve's initial linear section. 𝑏 and ℎ are the measured width and thickness of the specimen, respectively.

In addition to ( $σ_{u l t}$ ) and ( $E_{a p p}$ ), the toughness modulus ( $U_{T}$ ) can be calculated. It is worth noting that the modulus of toughness is the ability of a material to absorb energy in plastic deformation. It is defined as the amount of strain energy density (strain on a unit volume of material) that a given material can absorb before it fractures, which can be calculated as the area under the curve up to the break as follows:^{49,51,62,76,77}

U_{T} = \frac{E n e r g y}{v o l u m e} = \int_{0}^{ε_{f}} σ d ε

(3)

where ɛ_𝑓 signifies the failure strain.

Two perpendicular strain gauges were involved on the contrasting surfaces of each test specimen to determine the actual tensile modulus ( $E_{a c t .}$ ) and the Poisson’s ratio ( $v_{12})$ . Strain gauges were used by many authors^{49,74,78–81} to determine the actual tensile modulus ( $E_{a c t .}$ ) and the Poisson’s ratio ( $v_{12})$ . Strain gauges working principle is simple: the electrical resistance of a conducting wire is a function of the material’s electrical resistivity, cross-sectional area, and length. A strain gauge is basically a thin wire or a thin metallic foil formed in a grid shape. The grid is then glued to the specimen through a thin backing or carrier for support and insulation. This way, the strain on the specimen is directly transferred to the gauge, generating a change in its electrical resistance. This phenomenon is known as the piezo resistive effect.⁸² $E_{a c t}$ and $v_{12}$ were all assessed using the relationships presented below:

E_{a c t} = \frac{∆ σ_{S . G}}{∆ ε_{S . G}}

(4)

v_{12} = \frac{- ε_{t}}{ε_{L}}

(5)

Decision-making

COPRAS method has been increasingly used for the quantitative and qualitatively evaluation. The aim of the evaluation is to choose the best alternatives, ranking the alternatives in the order of their significance. This method compares the alternatives and determines their priorities under the conflicting criteria by taking into account the criteria weights.⁴¹ The stacking sequences investigated in this study were taken as design alternatives inside COPRAS framework, where they were rated according to their relative significance in relation to the performance criteria for tensile properties. Below is a description of how COPRAS and its equations were used, as stated in the literature review.^39,40,42

Phase 1

Create a preliminary decision matrix X.

In order to use COPRAS, you must first create an initial choice matrix (X) that maps the contenders (the stacking sequences to their attributes) that is, their tensile qualities. The matrix X can be written as follows:

X = {[x_{i j}]}_{m n} = [\begin{array}{c} x_{11} & \dots & x_{1 j} & \dots & x_{1 n} \\ ⋮ & ⋱ & ⋮ & ⋱ & ⋮ \\ x_{i 1} & \dots & x_{i j} & \dots & x_{i n} \\ ⋮ & ⋱ & ⋮ & ⋱ & ⋮ \\ x_{m 1} & \dots & x_{m j} & \dots & x_{m n} \end{array}]; i = 1, \dots, m, j = 1, \dots, n

(6)

where m and n, respectively, are the number of competitors and the number of tensile properties. The performance of the i_th specimen in terms of the j_th tensile property is thus represented by x_ij.

Phase 2

Make a decision matrix that is normalized “R”:

The selection method is significantly more difficult because the modified design indicators have different units and cannot be directly related to one another. As a result, in order to make the design indications comparable, the matrix X must be changed into a no-dimensional one. Decision matrix R, which has no dimensions, is written as:

R = {[r_{i j}]}_{m n} = \frac{x_{i j}}{\sum_{i = 1}^{m} x_{i j}}

(7)

where

r_{i j}

stands for the normalized

j_{t h}

indicator for the

i_{t h}

design.

Phase 3

Calculate the individual weights of each attribute ( $w_{j})$ . The following are the locations of $w_{j}$ for each attribute:

• The first step is to compare each pair of indicators separately. The total number of evaluations will be equal to N = (n (n - 1)/2). When the significance of the comparative tensile qualities differs for the selection process, the more significant indication should receive a score of 3, while the less significant indicator should receive a score of 1. On the other hand, if each of the compared indicators has equal weight in the selection process, both of them can receive a score of 2.

• Second, after evaluation, the sum score for each tensile property can be calculated as follows:

W_{j} = \sum_{i = 1}^{N} w_{i j}

(8)

• Third, you may get the weightage of the $j_{t h}$ tensile property by dividing the sum of each tensile property's scores, $w_{j}$ , by the overall total score, H:

w_{j} = \frac{W_{j}}{H} = \frac{W_{j}}{\sum_{j = 1}^{N} W_{j}}

(9)

Phase 4

Determine the weighted normalized decision matrix D:

The normalized matrix R can be multiplied by the specific weights assigned to each tensile attribute to obtain matrix D, which has the following notation:

D = {[y_{i j}]}_{m n} = r_{i j} x w_{j}

(10)

Where

y_{i j}

is the weighted normalized

j_{t h}

indicator for

i_{t h}

design.

Phase 5

Discover the summation of the positive and negative tensile properties for each stacking sequence alternative. The matrix D holds together positive and negative tensile properties denoted, respectively, as $+ y_{i j}$ and $- y_{i j}$ . The respectable design contender is the one that has a greater value for the positive tensile property and a smaller value for negative tensile property. Therefore, for each stacking sequences alternative the summation of the positive ( $S_{+ i}$ ) and negative ( $S_{- i}$ ) indicators would be found as follows:

S_{+ i} = \sum_{j = 1}^{n} + y_{i j} i = 1, \dots, m

(11)

S_{- i} = \sum_{j = 1}^{n} - y_{i j} i = 1, \dots, m

(12)

Step 6

Compute the relative significance ( $Q_{i}$ ) and the quantitative utility ( $U_{i}$ ) for each stacking sequences alternative. In order to characterize the significance of the design contenders in relation to the selection criteria, the chief procedures gained as a result of applying COPRAS are $Q_{i}$ and $U_{i}$ . These formulas can be used to create them:

Q_{i} = S_{+ i} + \frac{\sum_{i = 1}^{m} S_{- i}}{S_{- i} \sum_{i = 1}^{m} \frac{1}{S_{- i}}}

(13)

U_{i} = \frac{Q_{i}}{Q_{\max}}

(14)

The design option with the highest $Q_{i}$ and $U_{i}$ values is the proper one. Anywhere the $U_{i}$ value is used to rank the candidates, the option with the highest $U_{i}$ is placed first and the option with the lowest $U_{i}$ is placed last.

Results and discussions

Tensile test

Tensile properties

Figure 3 displays the stress-strain curves up to failure for tested FMLs. The strain values shown in Figure 3 were calculated based on the recorded displacement of the test machine's actuator. The stress-strain curves exhibit a nearly linear tendency before exhibiting a minor nonlinear trend up to the maximum force. A sudden failure was then noticed. As reported by Wang et al.^83,84 the stress-strain curve is roughly divided into two portions. The first portion (I), which is characterized by a nearly linear behavior up to 0.3% strain, enables the measurement of the tensile modulus. The uneven curve in the second portion (Π) has a nonlinear behavior. That is due to the incidence and accumulation of potential damage in addition to fiber breakage. Compared to portion (I), the curve’s slope steadily declines. The curve abruptly drops after the load hits its maximum value, at which the ultimate tensile strength and the elongation at break can be calculated.

Figure 3.

Tensile stress-strain curves until the complete failure of specimens for the developed FMLs (strain values calculated based on the recorded displacement of the test machine's actuator).

The obtained mechanical properties of the studied FMLs are shown in Figure 4. As shown in Figure 4(a), the Al/2C/4J/2C/Al specimen presents the highest ultimate tensile strength with a value of 137.29 MPa, an improvement of 181.9% over the Al/8J/Al specimen which records the lowest ultimate tensile strength of 48.7 MPa. Also, improvements of 89.67, 92.46, and 114% for, respectively, Al/2G/4J/2G/Al, Al/2A/4J/2A/Al, and Al/2B/4J/2B/Al were recorded.

Figure 4.

(a) Ultimate tensile strength, (b) failure strain, and (c) toughness modulus for the tested FMLs.

The tensile failure strain for the designed FMLs is presented in Figure 4(b). The highest and lowest failure strain values were observed for Al/2A/4J/2A and Al/2C/4J/2C/Al specimens, with values of 6.37 and 4.59%, respectively. It can be noted that the tensile failure strain of the Al/8J/Al specimen increased by 13.74, 21.56 and 1.90% for Al/2G/4J/2G/Al, Al/2A/4J/2A/Al, and Al/2B/4J/2B/Al, respectively. While it decreased by 12.40% compared with the Al/2C/4J/2C/Al specimen. It is clear that the hybridization of J-fiber with G, A, C, and B-fabrics significantly influences the tensile failure strain.

The tensile toughness modulus of the manufactured FMLs is shown in Figure 4 (c). With values of 3.40 and 1.57 MPa, respectively, the Al/2A/4J/2A/Al and Al/8J/Al specimens showed the greatest and lowest toughness modulus values. It is also important to observe that for Al/2G/4J/2G/Al, Al/2A/4J/2A/Al, Al/2C/4J/2C/Al, and Al/2B/4J/2B/Al specimens, the toughness modulus increased by 80.25, 116.56, 107, and 96.18%, respectively, compared with Al/8J/Al specimen.

The stress-strain curves of the tested FMLs specimens, depending on the strain readings from the strain gauges, are shown in Figure 5. The actual Young’s modulus was determined at 0.3% longitudinal strain. It can be extracted from Figure 6 that hybridization of Al/8J/Al specimen improves the actual modulus of elasticity by 60.10, 51.59, 133.85, and 100% for Al/2G/4J/2G/Al, Al/2A/4J/2A/Al, Al/2C/4J/2C/Al, and Al/2B/4J/2B/Al specimens, respectively. For more illustration and comparison, the actual and apparent modulus of elasticity for proposed FMLs are presented in Figure 6. It is clear from Figure 6 that the apparent modulus of elasticity increased by 51.69, 44.10, 111.86, and 96.61% for Al/2G/4J/2G/Al, Al/2A/4J/2A/Al, Al/2C/4J/2C/Al, and Al/2B/4J/2B/Al specimens, respectively, compared with Al/8J/Al specimen. While the actual modulus of elasticity increased by 60.10, 51.59, 133.85, and 100%, respectively, for Al/2G/4J/2G/Al, Al/2A/4J/2A/Al, Al/2C/4J/2C/Al, and Al/2B/4J/2B/Al specimens.

Figure 5.

Tensile stress–strain curves for the tested FMLs (obtained from strain gauge readings in the first stage of loading i.e., initial linear part).

Figure 6.

Actual and apparent Young’s modulus for the tested FMLs.

The Young's modulus, both apparent and actual, has the same tendency. The findings demonstrated that the actual modulus of elasticity values are considerably larger than their apparent values. This is brought on by a variety of factors, including slippage of the test specimen, shear deformation of the adhesive material separating the test specimen from the tabs, displacement brought on by gaps between joints and the testing machine's moving elements, and deformation of the frame columns, loading heads, and spindles. The apparent modulus of elasticity is lower than the actual modulus as a result of the additional lengthening caused by the generated displacements in the tested specimen. This finding was in agreement with those of Awd Allah et al.⁸⁰ and Selmy et al.⁷⁴

About Poisson’s ratio, it is clear from Figure 7 that the highest and lowest Poisson’s ratios were observed for Al/2A/4J/2A/Al and Al/2B/4J/2B/Al specimens with values of 0.44 and 0.30, respectively. Also, the hybridization improved Poisson’s ratio of Al/8J/Al specimen by 22.58, 41.94, and 16.13%, as shown respectively in Al/2G/4J/2G/Al, Al/2A/4J/2A/Al, and Al/2C/4J/2C/Al. The hybridization decreased Poisson’s ratio of the Al/8J/Al specimen by 3.23% as stated for the Al/2B/4J/2B/Al specimen.

Figure 7.

Poisson’s ratio for the tested FMLs.

The ultimate tensile strength value from the second portion of the stress-strain curves, obtained from strain values calculated based on the recorded displacement of the test machine's actuator, can be used in the design requirements. The slope of the initial linear portion presents the apparent Young’s modulus. The apparent Young’s modulus cannot be used in the design. While the actual Young’s modulus obtained from the initial linear portion of the stress-strain curves, obtained from strain gauge readings, can be used in the design requirements.

Specimen failure modes under tensile load

The failure modes of tensile test specimens are presented in Figure 8. Severe debonding between the composite part and Al-layers as a result of poor bonding was seen for failed specimens, i.e., Al/8J/Al, Al/2G/4J/2G/Al, Al/2A/4J/2A/Al, Al/2C/4J/2C/Al, and Al/2B/4J/2B/Al. While a strong bond was observed among composite part layers for all tested specimens, excluding the Al/2A/4J/2A/Al specimen. Debonding between the composite constituents was also found in the Al/2A/4J/2A/Al specimen. For Al/8J/Al and Al/2A/4J/2A/Al specimens, the failure occurs near the grips. It is worth noting that the same failure mode, i.e., location, is considered one of the typical tensile test failure modes stated in ASTM D3039. Failure of specimens near the grip was due to the stress concentration, which was developed from the lateral compressive stress of the grips. This is consistent with that recorded by Khashaba and Seif.⁸⁵

Figure 8.

Failure modes for the tested FMLs under tensile load.

Microstructural inspection

Numerous variables, such as fiber type, orientation, volume proportion, matrix type, lay-up order, and fiber-matrix interfacial bonding, can affect the damage in polymer composites. The fracture surfaces of the failed specimens were analyzed using SEM JSM 6100 in order to better understand the failure of the hybrids under various stress situations. Gold was used to treat the location of the fracture, and it was subsequently preserved in an ionizer. A 20 kV voltage was supplied to the surfaces in order to obtain photos. Following the tension testing, microscope images were taken through the laminate's thickness. SEM images of the failed surfaces of tensile specimens are displayed in Figure 9. Fiber pullout, delamination, and cracking were clearly visible.

Figure 9.

SEM of failed tensile specimens.

Scatter in the obtained results

One of the numerous factors that can affect test results is the manufacturing, preparation, handling, storage, test rig design, and experimental methodology of the specimens. Table 3 displays the statistical scatter, also known as the coefficient of variation (CV), for the experimental test results. For the identical stacking sequence, i.e., Al/8J/Al structure, the greatest CV was noted to be

σ_{u l t}

to be 12.31%, while the minimum CV was noted for ɛ_𝑓 to be 1.57%. The coefficient of variation (CV) values of all results are clearly less than 12.5%, which attests to the results' repeatability and visible accuracy. Rouzegar et al.⁸⁶ attributed the deviations observed between the results to the fabrication imperfections.

Table 3.

Tensile properties for the designed FMLs.

Stacking sequence	Calculations	$σ_{u l t}$ (MPa)	ɛ_𝑓 $(%)$	$U_{T}$ (MPa)	$E_{a c t}$ (GPa)	$v_{12}$
Al/8J/Al	Avg	48.70	5.24	1.57	9.75	0.310
	SD	1.48	0.08	0.18	1.20	0.024
	CV, %	3.04	1.57	11.46	12.31	7.742
Al/2G/4J/2G/Al	Avg	92.37	5.96	2.83	15.61	0.380
	SD	4.22	0.25	0.33	1.05	0.033
	CV, %	4.57	4.19	11.66	6.73	8.684
Al/2A/4J/2A/Al	Avg	93.73	6.37	3.40	14.78	0.440
	SD	8.74	0.69	0.17	0.91	0.017
	CV, %	9.32	10.83	5.00	6.16	3.86
Al/2C/4J/2C/Al	Avg	137.29	4.59	3.25	22.80	0.360
	SD	5.41	0.27	0.19	1.19	0.019
	CV, %	3.94	5.88	5.85	5.22	5.278
Al/2B/4J/2B/Al	Avg	104.21	5.34	3.08	19.50	0.300
	SD	2.24	0.26	0.31	0.83	0.031
	CV, %	2.15	4.87	10.06	4.26	10.334

Determining the optimum FMLs structure

The initial COPRAS decision-making matrix, illustrated in Table 4, includes, five stacking sequences, i.e., Al/8J/Al, Al/2G/4J/2G/Al, Al/2A/4J/2A/Al, Al/2C/4J/2C/Al, and Al/2B/4J/2B/Al, as well as five attributes that detail their tensile properties, including

σ_{u l t}

ε_{f}

U_{T}

E_{a c t}

and

v_{12}

. Furthermore, The normalized non-dimensional COPRAS decision matrix (R) of

σ_{u l t}

ε_{f}

U_{T}

E_{a c t}

and

v_{12}

were determined using the procedure explained in section 2.4 and detailed in Table 5. After that, the individual weightage of

σ_{u l t}

ε_{f}

U_{T}

E_{a c t}

and

v_{12}

were determined. All tensile properties were considered equal in importance for the selection process, and therefore they were given a score of two when compared with each other. The process of classifying the individual weightage is listed in Table 6. Turning to the next step of calculating the weighted normalized decision matrix (D) that is presented in Table 7. To define

S_{+ 1}

and

S_{- 1}

, all tensile properties are valuable responses, i.e., they are desirable to increase and/or be as maximum as possible, so here, the

S_{- 1}

term will be equal to “zero” because

S_{- 1}

term is used when the responses are desirable to decrease, i.e., be as minimum as possible. Following that, the values of

Q_{i}

and

U_{i}

for each stacking sequence were calculated, along with the rank of the stacking sequences in Table 8. Based on the COPRAS results, Al/2C/4J/2C/Al and Al/8J/Al stacking sequences were ranked first and last, respectively.

Table 4.

Initial COPRAS matrix (X).

Stacking sequence	Attributes
Stacking sequence	$σ_{u l t}$ (MPa)	$ε_{f}$	$U_{T}$ (MPa)	$E_{a c t}$ (GPa)	$v_{12}$
Al/8J/Al	48.70	5.24	1.57	9.75	0.31
Al/2G/4J/2G/Al	92.37	5.96	2.83	15.61	0.38
Al/2A/4J/2A/Al	93.73	6.37	3.40	14.78	0.44
Al/2C/4J/2C/Al	137.29	4.59	3.25	22.80	0.36
Al/2B/4J/2B/Al	104.21	5.34	3.08	19.50	0.30

Table 5.

The normalized COPRAS decision matrix (R).

Stacking sequence	Attributes
Stacking sequence	$σ_{u l t}$	$ε_{f}$	$U_{T}$	$E_{a c t}$	$v_{12}$
Al/8J/Al	0.102246	0.190545	0.111111	0.118268	0.173184
Al/2G/4J/2G/Al	0.193932	0.216727	0.200283	0.189350	0.212291
Al/2A/4J/2A/Al	0.196788	0.231636	0.240623	0.179282	0.245810
Al/2C/4J/2C/Al	0.288243	0.166909	0.230007	0.276565	0.201117
Al/2B/4J/2B/Al	0.218791	0.194182	0.217976	0.236536	0.167598

Table 6.

Individual weighting for each tensile property.

	$N = \frac{n (n - 1)}{2} = \frac{5 (5 - 1)}{2} = 10$
	$σ_{u l t}$	$ε_{f}$	$U_{T}$	$E_{a c t}$	$v_{12}$
$W_{i j}$	2	2	—	—	—
	2	—	2	—	—
	2	—	—	2	—
	2	—	—	-	2
	—	2	2	-	—
	—	2	—	2	—
	—	2	—	—	2
	—	—	2	2	—
	—	—	2	-	2
	—	—	-	2	2
$W_{j}$	8	8	8	8	8
G	40
$w_{j}$	0.2	0.2	0.2	0.2	0.2

Table 7.

Weighted normalized decision matrix (D).

Stacking sequence	Attributes
Stacking sequence	$σ_{u l t}$	$ε_{f}$	$U_{T}$	$E_{a c t}$	$v_{12}$
Al/8J/Al	0.020449	0.038109	0.022222	0.023654	0.034637
Al/2G/4J/2G/Al	0.038786	0.043345	0.040057	0.037870	0.042458
Al/2A/4J/2A/Al	0.039358	0.046327	0.048125	0.035856	0.049162
Al/2C/4J/2C/Al	0.057649	0.033382	0.046001	0.055313	0.040223
Al/2B/4J/2B/Al	0.043758	0.038836	0.043595	0.047307	0.033520

Table 8.

COPRAS results.

Stacking sequence	$Q_{i}$	$U_{i}$	Rank
Al/8J/Al	0.139071	0.60	5
Al/2G/4J/2G/Al	0.202517	0.87	4
Al/2A/4J/2A/Al	0.218828	0.94	2
Al/2C/4J/2C/Al	0.232568	1	1
Al/2B/4J/2B/Al	0.207017	0.89	3

Comparison between different materials

Table 9 lists some previous available data for the tensile strength of hybrid FMLs. Al/2C/4J/2C/Al hybrid FMLs shows better ultimate tensile strength than other hybrids published in the literature. The suggested FMLs can be installed in a variety of aerospace structures and automotive industry applications, including floors, roofs, firewalls, rear walls, side panels, underbody panels, dashboard components, door trim panels, seat cushions, real panel shelves, car frames, dashboard designs, headliners, decking, pallets, and headliners.

Table 9.

Comparison with previous available data for tensile strength of hybrid FMLs.

Material	Matrix	Ultimate tensile strength, MPa	Reference
Al/2C/4J/2C/Al	Epoxy	137.29	Current work
Al/G/K/G/Al	Polypropylene	90	Dhar Malingam et al⁸⁷
Al/K/G/K/Al	Polypropylene	75	Dhar Malingam et al⁸⁷
Al/C/4F/C/Al	Epoxy	92.26	Chandrasekar et al⁸⁸
Al/2F/2C/2F/Al	Epoxy	76.35	Chandrasekar et al⁸⁸
Al/2G/6J/2G/Al	Epoxy	88.73	Abd El-baky et al³⁰
Al/G/8J/G/Al	Epoxy	64.23	Abd El-baky et al³⁰

Future work

The current research can be expanded to look into additional critical FMLs related issues. The topics listed below are some suggestions for upcoming works:

• Investigating the flexural, in-plane shear, interlaminar shear, and bearing behaviors of the designed FMLs.

• Exploring the fatigue and creep behaviors of the designed FMLs.

• Studying the effects of the hybridization procedure on low and high-velocity impacts.

• Examining the effect of the tab alignment, tab material, tab angle, tab adhesive, grip type, grip pressure, and grip alignment on FMLs failure.

Conclusions

The goal of the present study is to experimentally examine the tensile properties of fiber metal laminates (FMLs). For this purpose, aluminum (Al) sheets, epoxy, and different types of fabrics, i.e., jute (J), glass (G), aramid (A), carbon (C), and basalt (B) were used to manufacture the designed FMLs. Specimens were prepared through hand layup and compression casting procedures. The effect of the hybridization between the J/epoxy composite and the other mentioned fabrics on the tensile properties was explored. Complex proportional assessment (COPRAS) was used to find the optimum FMLs structure. The following conclusions were drawn:

The hybridization was found to have significant effects on the tensile properties of the designed FMLs compared with the base structure in this work. i.e., the Al/8J/Al specimen. Adding G and A-fabrics to J-reinforced composite, i.e. Al/2G/4J/2G/Al and Al/2A/4J/2A/Al, respectively, enhances tensile properties, i.e. ultimate tensile strength, tensile strain to failure, tensile toughness modulus, and actual and apparent tensile modulus, and Poisson ratio of FMLs. All tensile properties of Al/8J/Al were improved by adding C and B-fabrics, i.e., Al/2C/4J/2C/Al and Al/2B/4J/2B/Al specimens, but the tensile failure strain and Poisson’s ratio were reduced, respectively. It was found that Al/2C/4J/2C/Al is the optimum hybrid FML structure in terms of tensile properties based on the COPRAS results. The fabricated hybrid FMLs are recommended for aerospace structures and automotive industry applications.

Footnotes

Acknowledgment

The author would like to thank Prince Sultan University for their support. The authors are thankful to the Deanship of Scientific Research at Najran University for funding this work, under the Research Groups Funding program grant code (NU/RG/SERC/12/8).

Declaration of conflicting interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by the funding this work, under the Research Groups Funding program grant code (NU/RG/SERC/12/8).

ORCID iDs

Marwa A Abd El-baky

Tamer A Sebaey

Data Availability Statement

The authors declare that all generated or analyzed during this study are included in this published article.

Appendix

References

Krishnakumar

. Fiber metal laminates — The synthesis of metals and composites. Mater Manuf Process 1994; 9: 295–354.

Sinmazçelik

Avcu

Bora

MÖ

, et al. A review: Fibre metal laminates, background, bonding types and applied test methods. Mater Des 2011; 32: 3671–3685.

Zhang

Guo

, et al. Influence of fiber type on the impact response of titanium-based fiber-metal laminates. Int J Impact Eng 2018; 114: 32–42.

Megahed

Abd El-baky

Alsaeedy

, et al. An experimental investigation on the effect of incorporation of different nanofillers on the mechanical characterization of fiber metal laminate. Compos B Eng 2019: 176.

Hynes

NRJ

Vignesh

Jappes

JTW

, et al. Effect of stacking sequence of fibre metal laminates with carbon fibre reinforced composites on mechanical attributes: Numerical simulations and experimental validation. Compos Sci Technol 2022: 221.

Sanjay

Madhu

Jawaid

, et al. Characterization and properties of natural fiber polymer composites: A comprehensive review. J Clean Prod 2018; 172: 566–581.

Vigneshwaran

Sundarakannan

John

, et al. Recent advancement in the natural fiber polymer composites: A comprehensive review. J Clean Prod 2020: 277.

Karthi

Kumaresan

Sathish

, et al. An overview: Natural fiber reinforced hybrid composites, chemical treatments and application areas. Mater Today Proc 2020; 27: 2828–2834.

Abd El-Baky

Attia

Abdelhaleem

, et al. Flax/basalt/E-glass fibers reinforced epoxy composites with enhanced mechanical properties. J Nat Fibers 2020; 19: 954–968.

10.

Farsani

Khalili

SMR

Daghigh

. Charpy impact response of basalt fiber reinforced epoxy and basalt fiber metal laminate composites: Experimental study. Int J Damage Mech 2013; 23: 729–744.

11.

Gunwant

. Prediction of tensile properties of novel natural fiber based fiber metal laminates (FMLs) using FEM. Int J Res Appl Sci Eng Technol 2018; 6: 1391–1396.

12.

Ishak

Sivakumar

Mansor

. The application of TRIZ on natural fibre metal laminate to reduce the weight of the car front hood. J Braz Soc Mech Sci Eng 2018; 40.

13.

Bahari-Sambran

Meuchelboeck

Kazemi-Khasragh

, et al. The effect of surface modified nanoclay on the interfacial and mechanical properties of basalt fiber metal laminates. Thin-Walled Struct 2019: 144.

14.

Ishak

Malingam

Mansor

, et al. Investigation of natural fibre metal laminate as car front hood. Mater Res Express 2021; 8: 025303.

15.

Kuan

Cantwell

Hazizan

, et al. The fracture properties of environmental-friendly fiber metal laminates. J Reinforc Plast Compos 2011; 30: 499–508.

16.

Amuthakkannan

Manikandan

Uthayakumar

. Mechanical properties of basalt and glass fiber reinforced polymer hybrid composites. J Adv Microsc Res 2014; 9: 44–49.

17.

Natrayan

Sathish

Baskara Sethupathy

, et al. Interlaminar shear, bending, and water retention behavior of Nano-SiO2 filler-incorporated Dharbai/glass fiber-based hybrid composites under cryogenic environment. Adsorpt Sci Technol 2022; 2022: 1–10.

18.

Velmurugan

Natrayan

Rao

, et al. Influence of epoxy/Nanosilica on mechanical performance of Hemp/Kevlar fiber reinforced hybrid composite with an ultrasonic frequency. Adsorpt Sci Technol 2022; 2022: 1–11.

19.

Ganesan

Kaliyamoorthy

. Utilization of taguchi technique to enhance the interlaminar shear strength of wood dust filled woven jute fiber reinforced polyester composites in cryogenic environment. J Nat Fibers 2020; 19: 1990–2001.

20.

Mavani

Mehta

Parsania

. Synthesis, fabrication, mechanical, electrical, and moisture absorption study of epoxy polyurethane–jute and epoxy polyurethane–jute–rice/wheat husk composites. J Appl Polym Sci 2007; 106: 1228–1233.

21.

Attia

Abd El-Baky

Hassan

, et al. Crashworthiness characteristics of carbon-jute-glass reinforced epoxy composite circular tubes. Polym Compos 2018; 39: E2245–E2261.

22.

Sivagurunathan

Way

SLT

Sivagurunathan

, et al. Effects of triggering mechanisms on the crashworthiness characteristics of square woven jute/epoxy composite tubes. J Reinforc Plast Compos 2018; 37: 824–840.

23.

El-Baky

MAA

Allah

MMA

Kamel

, et al. Lightweight cost-effective hybrid materials for energy absorption applications. Sci Rep 2022; 12: 21101.

24.

Mohammed

Rozyanty

Mohammed

, et al. Fabrication and characterization of zinc oxide nanoparticle-treated kenaf polymer composites for weather resistance based on a solar UV radiation. Bioresources 2018; 13: 6480–6496.

25.

Feng

DharMalingam

Zakaria

, et al. Investigation on the fatigue life characteristic of kenaf/glass woven-ply reinforced metal sandwich materials. J Sandw Struct Mater 2017; 21: 2440–2455.

26.

Azghan

Eslami-Farsani

. The effects of stacking sequence and thermal cycling on the flexural properties of laminate composites of aluminium-epoxy/basalt-glass fibres. Mater Res Express 2018; 5.

27.

Azghan

Bahari-Sambran

Eslami-Farsani

. Modeling and experimental study on the mechanical behavior of glass/basalt fiber metal laminates after thermal cycling. Int J Damage Mech 2021; 30: 1192–1212.

28.

Arpatappeh

Azghan

Eslami-Farsani

. The effect of stacking sequence of basalt and Kevlar fibers on the Charpy impact behavior of hybrid composites and fiber metal laminates. Proc IME C J Mech Eng Sci 2020; 234: 3270–3279.

29.

Zareei

Geranmayeh

Eslami-Farsani

. Interlaminar shear strength and tensile properties of environmentally-friendly fiber metal laminates reinforced by hybrid basalt and jute fibers. Polym Test 2019; 75: 205–212.

30.

Abd El-Baky

Alshorbagy

Alsaeedy

, et al. Fabrication of cost effective fiber metal laminates based on jute and glass fabrics for enhanced mechanical properties. J Nat Fibers 2020; 19: 303–318.

31.

Athanasopoulos

Riba

Athanasopoulou

. A decision support system for coating selection based on fuzzy logic and multi-criteria decision making. Expert Syst Appl 2009; 36: 10848–10853.

32.

Athawale

Chakraborty

. Material selection using multi-criteria decision-making methods: a comparative study. Proc Inst Mech Eng Part L 2012; 226: 266–285.

33.

Rao

. A decision making methodology for material selection using an improved compromise ranking method. Mater Des 2008; 29: 1949–1954.

34.

Zhao

Gong

, et al. Optimal selection of cutting tool materials based on multi-criteria decision-making methods in machining Al-Si piston alloy. Int J Adv Des Manuf Technol 2016; 86: 1055–1062.

35.

Maniya

Bhatt

. A selection of material using a novel type decision-making method: Preference selection index method. Mater Des 2010; 31: 1785–1789.

36.

Shanian

Savadogo

. A material selection model based on the concept of multiple attribute decision making. Mater Des 2006; 27: 329–337.

37.

Podvezko

. The Comparative Analysis of MCDA Methods SAW and COPRAS, vol. 22. Engineering Economics, 2011.

38.

Zavadskas

Kaklauskas

Turskis

, et al. Contractor selection multi-attribute model applying COPRAS method with grey interval numbers, 2008.

39.

Baroutaji

Arjunan

Singh

, et al. Crushing and energy absorption properties of additively manufactured concave thin-walled tubes. Results in Engineering 2022; 14.

40.

Ghose

Pradhan

Tamuli

, et al. Optimal material for solar electric vehicle application using an integrated Fuzzy-COPRAS model. Energy Sources, Part A Recovery, Util Environ Eff 2019; 45: 3859–3878.

41.

Garg

. Algorithms for possibility linguistic single-valued neutrosophic decision-making based on COPRAS and aggregation operators with new information measures. Measurement 2019; 138: 278–290.

42.

Zhao

Zhu

Zhou

, et al. Crashworthiness analysis and design of composite tapered tubes under multiple load cases. Compos Struct 2019; 222.

43.

M Awd Allah

Abdel-Aziem

A Abd El-baky

. Collapse behavior and energy absorbing characteristics of 3D-printed tubes with different infill pattern structures: an experimental study. Fibers Polym 2023: 1–14.

44.

Darko

Liang

. An extended COPRAS method for multiattribute group decision making based on dual hesitant fuzzy Maclaurin symmetric mean. Int J Intell Syst 2020; 35: 1021–1068.

45.

Varatharajulu

Duraiselvam

Kumar

, et al. Multi criteria decision making through TOPSIS and COPRAS on drilling parameters of magnesium AZ91. J Magnesium Alloys 2022; 10: 2857–2874.

46.

Kraujalienė

. Comparative analysis of multicriteria decision-making methods evaluating the efficiency of technology transfer. Bus Manag Educ 2019; 17: 72–93.

47.

Gon

Das

Paul

, et al. Jute composites as wood substitute. Int J Textil Sci 2013; 1: 84–93.

48.

Shah

Shaikh

Khan

, et al. Present status and future prospects of jute in nanotechnology: a review. Chem Rec 2021; 21: 1631–1665.

49.

Alshahrani

Sebaey

Awd Allah

, et al. Jute-basalt reinforced epoxy hybrid composites for lightweight structural automotive applications. J Compos Mater 2023.

50.

Mishra

Biswas

. Physical and mechanical properties of bi-directional jute fiber epoxy composites. Procedia Eng 2013; 51: 561–566.

51.

Abd El-baky

Attia

. Experimental study on the improvement of mechanical properties of GLARE using nanofillers. Polym Compos 2020; 41: 4130–4143.

52.

Boufaida

Farge

André

, et al. Influence of the fiber/matrix strength on the mechanical properties of a glass fiber/thermoplastic-matrix plain weave fabric composite. Compos Appl Sci Manuf 2015; 75: 28–38.

53.

Megahed

Tobbala

El-baky

MAA

. The effect of incorporation of hybrid silica and cobalt ferrite nanofillers on the mechanical characteristics of glass fiber-reinforced polymeric composites. Polym Compos 2020; 42: 271–284.

54.

Awd Allah

Shaker

Hassan

, et al. The influence of induced holes on crashworthy ability of glass reinforced epoxy square tubes. Polym Compos 2022.

55.

El Aal

MIA

Awd Allah

Abd El-baky

. Carbon-glass reinforced epoxy hybrid composites for crashworthy structural applications. Polym Compos 2023.

56.

Alshahrani

Sebaey

Awd Allah

, et al. Multi-response optimization of crashworthy performance of perforated thin walled tubes. J Compos Mater 2023; 57: 1579–1597.

57.

Alshahrani

Sebaey

Awd Allah

, et al. Quasi-static axial crushing performance of thin-walled tubes with circular hole discontinuities. J Compos Mater 2022.

58.

Allah

MMA

Hegazy

Alshahrani

, et al. Fiber metal laminates based on natural/synthesis fiber composite for vehicles industry: an experimental comparative study. Fibers Polym 2023: 1–13.

59.

El-Baky

MAA

Allah

MMA

Kamel

, et al. Energy absorption characteristics of E-glass/epoxy over-wrapped aluminum pipes with induced holes: an experimental research. Sci Rep 2022; 12: 21097.

60.

El-baky

MAA

Allah

MMA

Kamel

, et al. Fabrication of glass/jute hybrid composite over Wrapped aluminum cylinders: an advanced material for automotive applications. Fibers and Polymers, 2023.

61.

Megahed

Abd El-baky

Alsaeedy

, et al. Improvement of impact and water barrier properties of GLARE by incorporation of different types of nanoparticles. Fibers Polym 2020; 21: 840–848.

62.

Melaibari

Attia

Abd El-baky

. Understanding the effect of halloysite nanotubes addition upon the mechanical properties of glass fiber aluminum laminate. Fibers Polym 2021; 22: 1416–1433.

63.

Megahed

Ali-Eldin

Abd El Moezz

, et al. Synthesis of developed rice straw sheets and glass fiber-reinforced polyester composites. J Compos Mater 2020; 54: 3381–3394.

64.

Zakaria

Shelesh-nezhad

Chakherlou

, et al. Effects of aluminum surface treatments on the interfacial fracture toughness of carbon-fiber aluminum laminates. Eng Fract Mech 2017; 172: 139–151.

65.

Sharifi Golru

Attar

Ramezanzadeh

. Effects of surface treatment of aluminium alloy 1050 on the adhesion and anticorrosion properties of the epoxy coating. Appl Surf Sci 2015; 345: 360–368.

66.

Alshahrani

Sebaey

Awd Allah

, et al. Metal/polymer composite cylinders for crash energy absorption applications. Polym Compos 2022.

67.

Moussavi-Torshizi

Dariushi

Sadighi

, et al. A study on tensile properties of a novel fiber/metal laminates. Materials Science and Engineering: A 2010; 527: 4920–4925.

68.

Megahed

Abd El-baky

Alsaeedy

, et al. Synthesis effect of nano-fillers on the damage resistance of GLARE. Fibers Polym 2021; 22: 1366–1377.

69.

De Santis

de Felice

. Tensile behaviour of mortar-based composites for externally bonded reinforcement systems. Compos B Eng 2015; 68: 401–413.

70.

Khashaba

. In-plane shear properties of cross-ply composite laminates with different off-axis angles. Compos Struct 2004; 65: 167–177.

71.

Khashaba

El-Sonbaty

Selmy

, et al. Drilling analysis of woven glass fiber-reinforced/epoxy composites. J Compos Mater 2012; 47: 191–205.

72.

Selmy

Abd Elbaky

Ghazy

, et al. In-plane shear characteristics of unidirectional glass fiber/epoxy functionally graded (FG) and nonfunctionally graded (NFG) composite laminates with statistical analysis. J Compos Mater 2014; 49: 3347–3358.

73.

Kumar

Sridhar

Sivashanker

, et al. Tensile failure of adhesively bonded CFRP composite scarf joints. Mater Sci Eng, B 2006; 132: 113–120.

74.

Selmy

Elsesi

Azab

, et al. Monotonic properties of unidirectional glass fiber (U)/random glass fiber (R)/epoxy hybrid composites. Mater Des 2011; 32: 743–749.

75.

Ali

Yilmaz

Yildiz

. The effect of different tabbing methods on the damage progression and failure of carbon fiber reinforced composite material under tensile loading. Polym Test 2022; 111: 107612.

76.

Abd El-baky

Attia

Abdelhaleem

, et al. Mechanical characterization of hybrid composites based on flax, basalt and glass fibers. J Compos Mater 2020; 54: 4185–4205.

77.

. A simplified toughness estimation method based on standard tensile data. Int J Pres Ves Pip 2022: 199.

78.

Selmy

Abd El-baky

Hegazy

. Mechanical properties of inter-ply hybrid composites reinforced with glass and polyamide fibers. J Thermoplast Compos Mater 2018; 32: 267–293.

79.

Attia

El-baky

MAA

Abdelhaleem

, et al. Hybrid composite laminates reinforced with flax-basalt-glass woven fabrics for lightweight load bearing structures. J Ind Textil 2020; 51: 4622S–4664S.

80.

Awd Allah

Abd El-baky

Hassan

, et al. Crashworthiness performance of thin-walled Glass/Epoxy square tubes with circular cutouts: an experimental study. Fibers Polym 2022; 23: 3268–3281.

81.

Tan

Tong

Steven

, et al. Behavior of 3D orthogonal woven CFRP composites. Part I. Experimental investigation. Compos Appl Sci Manuf 2000; 31: 259–271.

82.

Montero

Farag

Díaz

, et al. Uncertainties associated with strain-measuring systems using resistance strain gauges. J Strain Anal Eng Des 2010; 46: 1–13.

83.

Wang

Zhang

, et al. Micromechanical modelling of the progressive failure in unidirectional composites reinforced with bamboo fibres. Mech Mater 2016; 94: 180–192.

84.

Wang

Zhou

Yang

, et al. Thermo-mechanical performance of polylactide composites reinforced with alkali-treated bamboo fibers, Polymers. vol. 10, 2018.

85.

Khashaba

Seif

. Effect of different loading conditions on the mechanical behavior of [0/±45/90] s woven composites. Compos Struct 2006; 74: 440–448.

86.

Rouzegar

Assaee

Elahi

, et al. Axial crushing of perforated metal and composite-metal tubes. J Braz Soc Mech Sci Eng 2018; 40.

87.

Dhar Malingam

Jumaat

, et al. Tensile and impact properties of cost-effective hybrid fiber metal laminate sandwich structures. Adv Polym Technol 2018; 37: 2385–2393.

88.

Chandrasekar

Ishak

Sapuan

, et al. Tensile and flexural properties of the hybrid flax/carbon based fibre metal laminate. Proceedings of the 5th postgraduate seminar on natural Fiber Composites 2016; 2016: 5–10.