Dynamic Stress Analysis of Smooth and Notched Fiber Composite Flexural Specimens

A detailed analysis of the dynamic stress field in smooth and notched fiber composite (Charpy-type) specimens is reported in this paper. The analysis is performed with the aid of the direct transient response analysis solution sequence of MSC/NASTRAN. Three unidirectional composites were chosen for the study. They are S-glass/epoxy, Kevlar/epoxy, and T-300/epoxy composite systems. The specimens are subjected to an impact load that is modeled as a triangular impulse with a maximum of 8960 N (2000 lb) and a duration of 1 ms. The results are compared with those of static analysis of the specimens subjected to a peak load of 8960 N (2000 lb). For the geometry and type of materials studied, the static analysis results gave close conservative estimates for the dynamic stresses.