含界面裂纹的压电智能梁断裂分析

Fracture analysis of an interfacial crack in a piezoelectric smart beam

针对压电智能梁界面裂纹的应力和基于能量原理的断裂行为进行了理论研究.基于Timoshenko梁理论,提出了一个压电智能梁界面断裂问题的分析模型,该模型考虑了胶层的影响,其中胶层采用考虑剥离和剪切刚度的连续弹簧模型,并推导了相应的控制方程,得到了界面剥离应力、剪切应力和能量释放率的解析解,通过实验和文献结果比较证明了解的有效性,通过典型算例分析表明:裂尖剥离应力和剪切应力的值处于同一量级,在预测压电智能梁界面断裂行为时,不能忽略电压作用下界面剥离应力产生的I型断裂.

The stress analysis and fracture behavior on the basis of the energy principle for an interfacial crack in a piezoelectric smart beam was studied in theory. Based on the Timoshenko beam theory, an analytical model was de- veloped for the piezoelectric smart beam with consideration to the adhesive layer, in which the adhesive layer was modeled as a continuous spring with the shear and peel stiffness, the governing equations for the piezoelectric smart beam were formulated firstly, and then analytical solutions were obtained for calculating inteffacial peel stress or and shear stress ~＂ and mode I and II energy release rates （EERs） GI and GII, respectively. The present solutions were verified by experiment results and those available in the literatures. The results indicated that the values of the peel stress of the crack tip and the shear stress are in the same order of magnitude, and the mode I fracture cannot be ig- nored for the prediction of interracial fracture behavior in the piezoelectric smart beam.