Vibration Induced Fatigue Analysis of [0n/90n]s Simply Supported Composite Plate Under Central Patch Impulse Loading

Abstract

Fatigue analysis of a simply supported composite plate with laminate configuration of [0n/90n]s under central patch impulse loading is presented using an analytical method. The method mainly consists of two steps, one, evaluation of vibration induced stresses for the given central patch impulse loading using modal analysis, and two, fatigue analysis using S–N curve approach, residual strength approach as well as failure function approach. The stress state in the plate was evaluated using viscous damping model as a function of time. The stress-time history was converted into block loading consisting of many sub-blocks. In the present study, the block loading consisted of four sub-blocks and a total of 175 numbers of cycles. The block loading was repeated after every 5 s. Next, fatigue analysis was carried out based on the block loading condition evaluated. Number of loading blocks for fatigue failure initiation and the location of failure were obtained. Studies were also carried out using two-dimensional (2D) finite element analysis (FEA). Number of loading blocks required to cause fatigue failure initiation under central patch impulse loading was found to be 3120 and 3170 using the analytical method and 2D FEA, respectively.