修正剪切GTN模型的缺口张角数值模拟
2021-08-12
作者:李鹏伟1,于正洋2
单位:1西安航空职业技术学院,; 2西安科技大学
摘要:人为预制含特定几何参数的对称环状V型缺口是新型金属棒料低应力旋弯致裂精密下料的关键工艺之一,合理的缺口效应不仅降低下料所需外载荷,还能有效节约下料时间。为获取合理缺口,使用细观损伤理论和数值模拟相结合的方法,以金属棒料作为研究对象,通过修正剪切GTN模型,对缺口张角为30°、60°和90°对称时进行分析;结合ABAQUS/Explict有限元分析软件中VUMAT子程序建立修正剪切GTN模型,对修正剪切GTN模型参数进行识别,并分析了不同缺口张角损伤分布规律。结果表明,与应力集中系数和应变率集中系数相似,随着缺口张角的不断增加,缺口根部的损伤不断降低。本文提出的修正剪切GTN模型可用于新型金属棒料低应力旋弯致裂精密下料缺口的选取。
关键词:V型缺口;修正剪切GTN模型;缺口张角;参数识别
中图分类号:TG356.3;TH164文献标志码:ADOI:10.3969/j.issn.1000-7008.2021.07.018
Numerical Simulation of Notched Angle of Modified Shear GTN Model
Li Pengwei,Yu Zhengyang
Abstract:Artificially prefabricated symmetrical annular V notch with specific geometric parameters is one of the key processes of new metal bar material with low stress rotary bending crack precision cutting.The reasonable notch effect not only reduces the external load required for cutting,but also effectively saves the cutting time.To obtain a reasonable notch,a combination of mesoscopic damage theory and numerical simulation is used to analyze the notch angle of symmetry 30,symmetry 60 and symmetry 120 by modifying the shear GTN model,and the modified shear GTN model is realized by VUMAT subroutine in finite element analysis software.The results show that the stress concentration coefficient and strain rate concentration coefficient are similar,and the damage of notch root decreases with the increase of notch angle.A modified shear GTN model can be used to select the notch of new metal bar material with low stress bending crack.
Keywords:V notch;modified shear GTN model;notch angle;parameter identification