个人信息Personal Information
副教授
硕士生导师
性别:男
毕业院校:大连理工大学
学位:博士
所在单位:机械工程学院
学科:车辆工程
办公地点:汽车基础实验教学中心A305
联系方式:13591183897
电子邮箱:yingliang@dlut.edu.cn
Thermal forming limit diagram (TFLD) of AA7075 aluminum alloy based on a modified continuum damage model: Experimental and theoretical investigations
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论文类型:期刊论文
第一作者:Rong, Hai
通讯作者:Ying, L (reprint author), Dalian Univ Technol, State Key Lab Struct Anal Ind Equipment, Fac Vehicle Engn & Mech, Sch Automot Engn, Linggong Rd 2, Dalian 116024, Liaoning, Peoples R China.
合写作者:Hu, Ping,Ying, Liang,Hou, Wenbin,Zhang, Jinghuang
发表时间:2019-06-01
发表刊物:INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
收录刊物:SCIE、EI
卷号:156
页面范围:59-73
ISSN号:0020-7403
关键字:Hot forming; AA7075 aluminum alloy; Continuum damage; Viscoplasticity; Thermal forming limit diagram (TFLD)
摘要:The formability of high strength Al-Zn-Mg-Cu (7000 series) aluminum alloys can be significantly improved at elevated temperatures, which has been paid more attention in recent decades. The formability of high strength aluminum alloys at elevated temperatures is essentially governed by thermal-damage evolution. In this paper, the main purpose is to propose a modified continuum damage model to describe the damage evolution and predict the fracture behavior of AA7075 at elevated temperatures (300-400 degrees C). Firstly, the thermal-mechanical behavior and forming limit of AA7075 alloy sheet were experimentally investigated using a series of isothermal uniaxial tensile tests and Nakajima tests at different temperatures and strain rates. A set of uniaxial continuum damage constitutive equations (CDCEs) coupling continuum damage mechanics (CDM) with unified viscoplastic theory was proposed to describe the uniaxial tensile behavior of AA7075. Subsequently, the uniaxial equations were extended into a set of multi-axial CDCEs by introducing a multi-axial damage correction formula to predict the TFLD of AA7075. Besides, the forward Euler method was employed to integrate the proposed CDCEs, and the corresponding material constants of CDCEs were further calibrated by the non-dominated sorting genetic algorithmII(NSGA-II). The results illustrate that the thermal flow behavior and the TFLD of AA7075 alloy can be predicted successfully by the proposed damage model. Detailed discussions about the effects of corresponding parameters on the computed TFLD indicate the established multi-axial CDCEs are flexible and beneficial to the application potential in numerical simulation of hot sheet metal forming.