基于损伤曲率模态的简支梁损伤识别

STRUCTURAL DAMAGE IDENTIFICATION OF THE SIMPLE SUPPORTED BEAM BASED ON DAMAGE CURVATURE MODAL

为了利用简支梁损伤状态的一阶曲率模态对其进行损伤识别,通过结构位移计算推导了简支梁损伤前后在分布惯性力作用下节点的曲率模态理论值,提出利用曲率模态差指标作为标识量进行损伤定位,并基于简支梁损伤前后节点曲率模态值的变化规律建立了计算损伤程度的计算式。针对实际工程中无法获取结构原始模态参数的问题,提出采用函数拟合构建未损伤状态曲率模态曲线的方法。通过一简支梁数值算例,设置多个损伤工况进行损伤识别,结果表明该方法能有效识别简支梁的各处损伤。

The first mode of damage state was used to identify the damage degree of simple supported beams.The theoretical value of modal curvature of beam structures under distributed inertial force was deduced by the structural displacement calculation.The damage location was identified by the modal curvature difference,and the expression between damage degree and node curvature modal value before and after structural damage is established.For the original modal parameters of the structure beam,the method of constructing curvature modal curve of simple support⁃ed beam in healthy state by function fitting was proposed.Through the numerical case of a simple supported beam,the results of which show that the damage identification method has high accuracy.