Compression failure behavior of CFRP strips containing delaminations
- Univ. of Stuttgart (Germany). Institute for Aircraft Design
The failure mechanics of the so-called delamination buckling is investigated theoretically as well as experimentally considering laminated plate strips made of carbon-fiber reinforced epoxy. The laminates contain one through-width delamination between two adjacent plies, which separates them into two sublaminates. The deformation behavior caused by the in-plane compressive loading is characterized by the buckling of the two sublaminates, which results in large out-of-plane displacements. The theoretical study is based on a two-dimensional finite element model. Results of a geometrically non-linear analysis covering pre and post-buckling as well as fracture mechanics are presented. The deformed shapes of FE models with 5 different crack lengths are calculated for various load steps. To illustrate the structural behavior, axial force and out-of-plane displacement are plotted versus axial displacement. In order to predict crack growth, the energy release rates for mode 1 and mode 2 are determined using the virtual crack closure method. The dependence of G{sub I} and G{sub II} upon crack length and axial displacement is shown. The results of the finite clement analyses are compared with experimental data from compression tests, which were performed with plate strips containing artificial delaminations. The specimens were mounted in a specially designed compression fixture, and loaded until the total failure took place. The axial force and axial strain as well as the transverse displacements were recorded continuously during the test. Whereas the crack length was measured only at certain load steps.
- OSTI ID:
- 143560
- Report Number(s):
- CONF-930246--; ISBN 0-87339-251-5
- Country of Publication:
- United States
- Language:
- English
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