应变模态振型指标下的泡沫铝夹层梁损伤识别

Damage detection of aluminum foam sandwich beam based on strain mode

阐述了通过应变模态振型对结构进行损伤识别的原理,根据泡沫铝夹层梁的结构特性建立了基于修正Timoshenko梁理论的泡沫铝夹层梁的弯曲振动方程。运用ANSYS Workbench提取泡沫铝夹层梁的模态参数,通过固有频率解析解验证了仿真数据的有效性。探讨了固有频率、位移模态以及应变模态对泡沫铝夹层梁损伤识别的敏感度,并验证了归一化应变模态振型差指标和增强应变模态振型差指标对泡沫铝夹层梁进行损伤识别具有更高的精度。

The principle of structural damage identification through strain mode shapes is explained.According to the structural characteristics of the aluminum foam sandwich beam,an analytical formula for the bending vibration theory of the aluminum foam sandwich beam based on the modified Timoshenko beam theory is established.The modal parameters of the foam aluminum sandwich beam are extracted based on Ansys Workbench,and the validity of the simulation data is verified by the analytical solution of the natural frequency.The sensitivity of natural frequency,displacement mode and strain mode to the damage identification of foam aluminum sandwich beams is discussed,and the normalized strain mode shape difference index and the enhanced strain mode shape difference index are proposed and verified for aluminum foam sandwich beams.It has higher accuracy for damage identification of aluminum foam sandwich beams.