含裂纹梁的动力特性

 本文研究了含裂纹梁的动力特性。首先,由应力强度因子积分得到含裂纹单元体的刚阵,继而提出了一种有限元方法。将该方法应用于单边裂纹悬臂梁,计算出不同裂纹长度与位置时梁的固有频率,结果与实验值吻合良好。最后,给出了一种确定裂纹位置的简捷方法。

DYNAMIC BEHAVIOUR OF A CANTILEVER BEAM WITH CRACKS

In this paper, the dynamic behaviour of a beam with cracks is studied. At firsts the element stiffness matrix of the beam with cracks is derived from an integration of stress in tensity factors and then a finite element model of cracked beam is established. Applying FEM to a cantilever beam with an edge-crack,the eigenfrequencies are determined for different crack lengths and crack positions. Results show an excellent agreement in comparison with the experimental ones, A simple and direct method to determine the crack position is proposed based on the discussion of the relationship between the crack and the eigencoupie. In principle, the suggested method may be extended to complex structures, if the stress intensity factors of crack are known.