异体材料环形切口金属棒材四点弯曲裂纹起裂机理研究  

Research on the mechanism of four-point bending crack initiation of heterologous material toroidal notch metal bar

作　　者：李有堂[1] 姚恒星 Li Youtang;Yao Hengxing(School of Mechanical and Electrical Engineering,Lanzhou University of Technology,Gansu Lanzhou,730050,China)

机构地区：[1]兰州理工大学机电工程学院,甘肃兰州730050

出　　处：《机械设计与制造工程》2024年第12期21-26,共6页Machine Design and Manufacturing Engineering

摘　　要：针对金属棒材应力断料中环形切口预制的问题,提出采用由异体材料形成环形切口的裂纹制造方式,利用Deform有限元模拟软件,对金属棒材裂纹起裂的过程进行了有限元数值模拟实验,研究了环形切口几何参数和加载参数对金属棒材裂纹起裂偏距、起裂角和临界加载力的影响规律。通过有限元数值模拟实验,确定了加载参数的合理取值范围和环形切口几何参数的合理取值条件,即环形切口张角为45°、金属棒材直径与下料模型直径比约为0.7且环形切口深度大于等于3 mm、加载力臂和夹持力臂的取值应使得模型趋向于三点弯曲形式。实验研究表明,环形切口几何参数对裂纹起裂偏距和起裂角的影响较大,加载参数对裂纹起裂临界加载力的影响较大。In order to the prefabrication of ring notch in metal bar stress fracture,a crack manufacturing method is proposed by forming ring notch with heterologous material.Using Deform finite element simulation software,the finite element numerical simulation experiment is carried out on the crack initiation process of metal bars.The influences of annular notch geometric parameters and loading parameters on the crack initiation deviation,crack initiation angle and critical load of metal bars are studied.Through the finite element numerical simulation experiment,the reasonable range of loading parameters and the reasonable conditions of the geometrical parameters of the ring incision are determined.That is,the ring incision angle is 45°,the diameter ratio of the metal bar to the blanking model is about 0.7 and the depth of the ring incision is greater than or equal to 3 mm,and the values of the loading arm and the clamping arm should make the model tend to the form of"three-point bending".The experimental results show that the geometrical parameters of the annular notch have great influence on the crack initiation deviation and crack initiation angle of crack initiation,and the loading parameters have great influence on the critical load of crack initiation.

关 键 词：金属棒材 裂纹起裂 起裂偏距 起裂角 临界加载力 数值模拟 

分 类 号：TG301[金属学及工艺—金属压力加工] O346[理学—固体力学]