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The effect of stress concentration on the compressive failure behavior of a carbon fiber composite laminate with an open hole is experimentally and numerically studied. The aspect ratio of the elli...

In the present study, strain-rate and temperature dependence of the transverse tensile failure mode of unidirectional heat-resistant carbon fiber-reinforced plastics is numerically simulated by finite element analyses. In the analyses, interface failure and matrix failure are represented by cohesive zone modeling and continuum damage mechanics, respectively. For the continuum damage mechanics, Christensen's failure criteria of multi-axial stress states for each strain rate are applied to the matrix properties. Interfacial properties which are obtained by microbond test are introduced into cohesive zone modeling. A time-temperature superposition principle approach is applied in order to translate the difference in temperature as the difference in strain rate. The damage initiation depends on strain rate and temperature, while the cohesive zone modeling is assumed to be temperature- and time-independent. The initial damage starting points and the failure mode are predicted in numerical analysis. The transverse tensile strengths in analysis results are compared with the three-point bending testing results.

In the present study, strain-rate dependence and temperature dependence of failure mode are numerically simulated by finite element analyses. In the analyses, interface failure and matrix failure are expressed by cohesive zone modeling and continuum damage mechanics, respectively. It is assumed that the damage initiates dependently of strain rate and temperature, and cohesive zone modeling is assumed to be temperature- and time-independent. In the continuum damage mechanics, Christensen’s failure criterion of multi-axial stress states for each strain rate are applied into the resin properties. Interfacial strength which is obtained by microbond test is introduced into cohesive zone modeling. When temperature is high and/or strain rate is low, matrix crack occurs very often and the failure mode is matrix-failuredominant mode. On the other hand, when temperature is low and/or strain rate is high, interface crack significant, i.e. failure mode becomes interface-crack-dominant mode.