Performance of Lightweight Materials for Vehicle Interior Trim Subject to Monotonic Loading and Low Velocity Impact

The usage of lightweight materials such as plastics and their derivatives continues to increase in automobiles driven by the urgency for weight reduction. For structural performance, body components such as A-pillar or B-pillar trim, instrument panel, etc. have to meet various requirements including resistance to penetration and energy absorption capability under impact indentation. A range of plain and reinforced thermoplastics and thermosetting plastics has been considered in the present study in the form of plates which are subject to low velocity perforation in a drop-weight impact testing set-up with a rigid cylindrical indenter fitted to a tup. The tested plates are made of polypropylene (PP), nanoclay-reinforced PP of various percentages of nanoclay content, wood-PP composites of different volume fractions of wood fiber, a jute-polyester composite, and a hybrid jute-polyester reinforced with steel. In order to estimate the energy absorbed by a test specimen, a novel procedure is followed in which the initial (i.e. just before impact) and final (i.e. immediately after perforation) velocities of the impactor system are obtained using images recorded by a high speed camera. The energy absorbing capability of a plate during failure caused by transverse impact loading is quantified with the aid of a non-dimensional parameter. The efficacy of the various materials tested is compared by taking into account values of the latter parameter and density. The present study indicates that hybrid jute-polyester composite is most efficient in terms of energy absorption and localization of damage when compared to plain PP which is commonly used for making panels for automotive interior trim.