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对轴向荷载下,各包含一个斜向半椭圆形裂纹的钢管的疲劳断裂进行试验和理论研究。这个裂纹相对于荷载的轴的倾斜角在0°~90°之间变化。事实上,在微观尺度上,断裂面并不绝对平滑,从微观结构来讲更是倾向于粗糙的。这些粗糙表面相互之间共同的滑动作用导致了断裂面之间的压力和摩擦应力场。提出一个包含断裂面相互作用对裂纹扩展影响的新的裂纹扩展模型。断裂面被认为是一种h为粗糙高度、λ为波长的工厂屋顶的形式。随后,使用该模型预测复杂应力状态下钢管的疲劳裂纹扩展。
Experimental and theoretical studies on the fatigue fracture of steel tubes with one oblique semi-elliptical crack under axial load were carried out. The angle of inclination of this crack with respect to the axis of the load varies between 0 ° and 90 °. In fact, at the microscopic scale, the fracture surface is not absolutely smooth and even microstructurally it tends to be rough. The sliding effect of these rough surfaces with each other leads to the pressure and frictional stress field between the fracture surfaces. A new crack growth model is proposed, which includes the influence of fracture surface interaction on the crack propagation. The fracture surface is considered to be a form of factory roof where h is the roughness height and λ is the wavelength. Subsequently, the model was used to predict the fatigue crack growth of steel tubes under complex stress conditions.