热冲击下层状梯度材料表面裂纹的能量释放率

Energy Release Rates of Surface Crack in Functionally Graded Laminates under Thermal Shock

用数值方法分析了具有表面裂纹的层状梯度材料在热冲击荷载下 ,裂纹所对应的能量释放率随时间变化的规律 ,着重讨论了呈现梯度变化的材料力学和热学参数对能量释放率的影响 .结果发现和均匀材料相比 ,呈梯度变化的热膨胀系数使裂纹的能量释放率有非常大的增加 。

Energy release rates of a surface crack in functionally graded laminates under thermal shock are analyzed numerically.Influence of the thermal and mechanical parameters of the laminates on the energy release rates of the crack is discussed.It is found that,in comparison with the case of homogeneous material,the energy release rate for the case of the functionally graded laminates increases greatly,and the difference of the thermal expansion of the laminates is a main factor to increase the energy release rate.