Validation of an indentor system for evaluating truck seat cushions

Abstract

The objective of this study was to validate an indentor system—called a cushion loading indentor (CLI)—for use in objectively evaluating seat cushion performance for heavy truck seats. Included in this study is a detailed description of the five-component indentor design, with major components being a polyurethane buttocks mould and a variable weighting system. Validation of the CLI was performed by comparing its interface pressure distribution with five human test subjects for four different seating surfaces. The results demonstrate that the CLI is both more repeatable than the human test subjects and provides similar pressure distribution to that of a seated person. Furthermore, it is shown that the CLI is valid for dynamic testing of heavy truck seat cushions owing to the inclusion of the seat suspension, which significantly reduces the dynamic complexity between the cushion and the seated person.