Stress and Strain Distribution of Thick Composites with Various Types of Fiber Waviness under Tensile and Compressive Loadings

다양한 형태의 보강섬유 굴곡을 가지는 두꺼운 복합재료의 인장/압축 하중 하에서의 응력/변형률 분포

A FEA(finite element analysis) model was proposed to study stress and strain distributions in thick composites with various types of fiber waviness under tensile and compressive loadings. Three types of model were considered in this study: uniform fiber waviness, graded fiber waviness and localized fiber waviness models. In the analysis, both material and geometrical nonlinearities due to fiber waviness were incorporated into the model utilizing energy density and incremental method. The strain distributions of uniform fiber waviness model were strongly influenced whereas the stress distributions were little influenced by fiber waviness. The stress and strain distributions of graded and localized fiber waviness models showed more complex distributions than those of uniform fiber waviness model due to the variation of fiber waviness along the thickness and length directions. It was concluded that the stress and strain distributions of composites with fiber waviness were significantly affected by types of fiber waviness.