热镀锌双相钢DP590力学特性及其本构模型

通过单轴拉伸试验及液压扩胀试验,分析了热镀锌双相钢DP590准静态条件下力学特性及大应变力学行为,同时利用高速电液伺服试验机及分离式Hopkinson拉杆试验机测试了该材料中高应变率下的动态力学特性.试验数据表明,DP590呈现微弱的各向异性,同时其动态等效应力应变曲线簇具有随应变增加而渐进收敛的特性.在此基础上提出了一个基于YLD2003各向异性屈服准则的混合流动硬化收敛型黏塑性本构模型,并提供了模型参数的识别方法.利用该本构模型对一薄壁管梁结构的轴向冲击试验过程进行了数值模拟,结果表明,采用新本构的仿真模型可以准确模拟试验结果,因而该本构更适用于工程精细仿真的需要.

Mechanical Properties of Hot dip Galvanized Dual Phase Steel DP590 and Its Constitutive Model

Quasi static mechanical property and flow behavior in large strain of hot dip galvanized dual phase steels, DP590, were investigated by uniaxial tensile and bulge tests respectively. Dynamic mechanical properties of DP590 at medium to high strain rates were also tested by high speed electro hydraulic servo test machine and SHTB device. It is shown that DP590 possesses weak anisotropy and its dynamic effective stress strain curves tend to be convergent as the strain increases. Therefore, a convergent viscoplastic constitutive with a mixed hardening rule based on anisotropy yielding criteria, YLD2003, was proposed. In addition, parameter identification for new constitutive was discussed. Finally, the proposed constitutive was adopted to simulate the crash behavior of a thin walled structure subjected to axial loading condition. The simulation results showed high agreement with those of the experiment，which proved the proposed constitutive was more suitable for fine simulation analysis.