Impact Resistance of Cross-Plied Polyphenylene Sulfide Composites

Abstract

Impact resistance and residual strength of thermoplastic polyphenylene sulfide (PPS) composites are studied with regard to laminate configurations consisting of cross-plied Glass/PPS, 50% hybrid Glass/Graphite/PPS and Graphite/PPS. By means of impact testing, ballistic limit measurements show that hybridization can be used to modify penetration resistance. Residual strength measurements show that the percent reduction in strength is about 50% for all the laminate configurations The original strength values are Glass/PPS-440 MPa (63 ksi), 50% hybrid Glass/Graphite/PPS-530 MPa (76 ksi), and Graphite/PPS-585 MPa (84 ksi). For microstructural comparison of the damage modes and progression, two series of impact tests were done In one series, impact was inhibited such that only damage initiation was possible, and in the second series, the impact was allowed to a completion. Three impact velocities, 10 m/sec, 20 m/sec, and 30 m/sec were used. Microstructural observation of damage initiation alone revealed matrix cracking in Glass/PPS, delamination in Glass/Graphite/PPS, and spalling of Graphite/PPS. Further, upon completion of impact, Glass/PPS is minimally perforated and exhibits matrix crack ing and delamination, Glass/Graphite/PPS is delaminated and matrix cracking has oc curred and there is shear cut-out, and Graphite/PPS is severely sheared and forms a plug. Thus, by evaluating the microstructure after damage initiation and completion, the damage development and progression for each configuration is described.