Analysis of delamination in composite laminates under low-velocity impact
Abstract
Composite laminates subjected to foreign object impact often experience extreme damage that may not be visible on the impacted surface. This damage in the form of delamination may lead to significant reduction in compressive strength of the laminate. In this study, the fracture mechanics approach is employed to predict the extent of delamination for a given impact condition. Static linear beam models for two types of specimens are developed and verified by 2-D plane strain finite element methods. Thermal residual stresses are also considered in the analysis. Then, static three-point bending tests are performed on four different lay-ups of laminates to determine interlaminar fracture toughness. A drop-weight impact tower is constructed to perform the dynamic impact test. The validity of the quasi-static assumption for the drop-weight impact is examined. A simple spring-mass model is used to predict the peak load of the drop-weight impact. Also, the methodology of the prediction of impact-induced delamination under drop-weight impact is proposed and verified by the test results.
Degree
Ph.D.
Advisors
Sun, Purdue University.
Subject Area
Aerospace materials
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