弹塑性变形对螺栓应力和轴力分布的影响

Elastic-plastic deformation effect on distribution of stress and axial force in a threaded bolt

为了解决液压机用锯齿形螺纹在啮合螺纹段第一扣牙根处的疲劳断裂问题,采用非线性有限元数值模拟方法,以ANSYS软件为工具,考虑螺栓和螺母材料的弹塑性,研究了不同轴力作用下啮合螺纹段的应力和变形规律。给出不同轴力下螺栓啮合螺纹段中轴力和牙根峰值等效应力沿螺母高度的非线性分布规律,得出螺母螺纹约70%塑性变形可使螺栓牙根峰值等效应力和牙间轴力趋于均匀分布的结论,为大型螺栓连接结构的弹塑性设计提供了有益指导。

In order to solve fatigue fracture of hackle thread used for hydraulic press at roots of the first goggle in a threaded bolt,stress and deformation of bolt thread under the action of axial force were researched by using nonlinear finite element method and ANSYS software, taking bolt and nut material elastic-plasticity into consideration. The nonlinear distribution laws of Top equivalent stress in roots of threaded bolt and distributing axial force between bolt threads and nut threads along the nut axial height was obtained. Conclusion that about 70% plastic deformation of nut threads nearly make uniform distribution of top equivalent stress of roots of bolt thread and distributing axial force between bolt threads and nut threads was drawn,which benefit to design of large threaded bolts based on elastic-plastic.