悬臂梁裂纹参数的识别方法

以梁振动理论作为基础 ,将含裂纹梁的振动问题转化为由弹性铰联接两个弹性梁系统的振动问题 ,得到理论计算含裂纹梁振动频率的特征方程。由此特征方程计算得到裂纹深度参数和位置参数变化时悬臂梁振动固有频率的变化规律。利用计算裂纹悬臂梁振动固有频率的特征方程 ,提出一种辩识裂纹深度和位置参数的数值计算方法。并通过对模拟悬臂梁裂纹的分析说明文中方法的有效性。

CRACK IDENTIFICATION IN A CANTILEVER BEAM

The present research studies the problem of crack identification of a cantilever beam. The effect of the crack is apparent in its neighborhood only, the beam can be treated as two uniform beams, connected by a bending spring of local flexibility at the crack location. The characteristic equation for the vibration frequencies of the cracked cantilever beam is obtained. An identification method is developed, which requires monitoring of two bending natural frequencies of the beam. The location and depth of the crack may be found by the roots of the nonlinear equation. The proposed method was verified by numerical simulation and experiment results.