【摘要】 给出了一种利用有限元技术模拟周期性张力载荷作用下圆柱形部件内裂纹扩展过程的方法。首先利用一系列点定义裂纹前沿,据此形成包含奇异单元的二维有限元网格,再扩展为三维网格,然后利用有限元法进行应力应变分析,最后使用Paris定律计算局部扩展增量,以此来更新裂纹的形状和尺寸。该方法还能够自动地重复执行扩展仿真。文中还对具有不同半径比的椭圆形和具有不规则形状的初始裂纹的扩展过程进行了仿真和分析比较,以此来取得裂纹在扩展过程中的形状变化特征。更多还原

【Abstract】 The paper proposes a method to simulate the fatigue crack growth by finite element technique for surface cracks of round bars under cyclic tension loading.First,it defines a crack front using a set of points,and generates a 2-D finite element mesh by it,and extends the 2D mesh to 3D mesh at last.Secondly,the stress and strain are analysed and thirdly the local increment is calculated to update the crack’s shape and size.It permits the growth to be automatically advanced on a step-by-step basis.Elliptical cracks with different radius ratio and irregular shape crack are tested using the method proposed,and the results are analyzed to obtain the shape development characteristic and aspect ratio change during crack growth.更多还原