【摘要】 普通芯棒冷挤压强化小孔易产生芯棒断裂、孔表面不光整等问题,引入超声冷挤压孔强化技术可在一定程度上解决这些问题。由于超声挤压强化速度快,按照传统的实验方法,很难对超声振动挤压机理进一步分析与理解。本文尝试采用有限元分析软件ABAQUS模拟超声振动挤压强化和传统冷挤压强化小孔的过程,对比分析该过程的两种强化方式的力学特性。结果表明:在挤压强化过程中施加超声振动能够有效减小接触力和摩擦力;在挤压强化过程中施加超声振动后,接触力和摩擦力随着时间的增加,其减小的效果更明显,说明该作用具有传承叠加效果;超声挤压在前锥段有一定冲击作用,工作段作用效果要优于前锥段;超声挤压强化小孔一定程度上丰富了定量研究超声强化理论,且对实际生产中提高强化效率、降低成本、减小摩擦、解决芯棒断裂问题具有指导意义。更多还原

【Abstract】 Ordinary rod cold extrusion strengthening small hole easily leading to fracture of rods and non-finishing hole surface,ultrasonic strengthening hole technology are introduced,which can solve these problems to a certain extent.Due to the high speed of ultrasonic vibration extrusion,according to the traditional experiment method,it is difficult to solve the further mechanism analysis and understanding of ultrasonic vibration extrusion. In this paper,the finite element analysis software ABAQUS is used to simulate the process of ultrasonic vibration extrusion and traditional cold extrusion,and the mechanical properties of the two strengthening methods are compared and analyzed. The results show that the ultrasonic vibration can effectively reduce the contact force and the friction force during the extrusion strengthening process. After the ultrasonic vibration is applied during the extrusion strengthening process,the effect of the contact force and the friction increases with time,which shows that the effect has the effect of superposition. Ultrasonic extrusion has a certain impact effect in the front cone section,and the effect of the working section is better than that of the front cone segment. To some extent,Ultrasonic extrusion strengthening holes enrich the theory of quantitative ultrasonic strengthening,and has guiding significance for improving the production efficiency,reducing costs,reducing friction,and solving the problem of core rod fracture in the process of production.更多还原