Low-velocity impact behavior of injection over-molded short/continuous fiber reinforced polypropylene composites

Injection over-molded short/continuous fiber composites are getting attention in automotive industry due to their recyclability, light weight, good specific strength, short processing time and ability to make complex shaped structures. The low-velocity impact behavior and compression strength after impact of short glass fiber reinforced polypropylene (SGFPP) and quai-isotropic composites (QI) and injection over-molded short/continuous glass fiber polypropylene (OM) composites were investigated by drop-weight impact and compression after impact tests. The low-velocity impact tests revealed higher specific absorbed energy for OM specimens compared with SGFPP and QI specimens. The impact energy is dissipated in OM composites primarily through interface debonding, delamination and damage in the short fiber composite core. Whereas, SGFPP and QI specimens dissipated the energy by complete perforation and delamination, respectively. Although QI specimens can bear more compressive load after impact, the OM specimens exhibited higher specific compression strength after impact compared with SGFPP and QI samples.