耦合孪生的TWIP钢多晶体塑性变形行为研究

发布时间：2019-08-16 11:30

【摘要】：基于已建立的单晶体塑性模型,建立了耦合孪生的孪生诱发塑性(TWIP)钢多晶体塑性模型,该模型采用有限元多晶均匀化处理相邻晶粒间的几何协调和应力平衡条件,获得了单晶体与多晶体状态变量的关系,开发了基于ABAQUS/UMAT的计算程序.采用EBSD研究了TWIP钢拉伸应变分别为0.27和0.6时的织构变化,并对模型进行了应力应变及织构演化的验证.用该本构模型分别建立了拉伸、压缩和扭转3种简单加载条件下的有限元模型,分析了不同变形条件下的宏观力学响应及织构演化规律.结果表明:拉伸变形过程中,应变硬化现象和织构密度水平随应变增加而增强;在压缩过程中,织构类型随应变增加而发生变化,但是织构密度水平基本不变;而在扭转过程中,当扭转应变较小时,基本无织构形成,随着应变增加,织构逐渐显现出来,这是因为变形较小时,圆柱沿径向方向内部变形量较小,故织构不明显.
[Abstract]:Based on the established single crystal plastic model, a coupled twin induced plastic (TWIP) steel polycrystal plastic model is established. The geometric coordination and stress balance conditions between adjacent grains are treated by finite element polycrystal homogenization, the relationship between single crystal and polycrystal state variables is obtained, and a calculation program based on ABAQUS/UMAT is developed. The texture changes of TWIP steel with tensile strain of 0.27 and 0.6, respectively, were studied by EBSD, and the stress, strain and texture evolution of the model were verified. The finite element models under three simple loading conditions, tensile, compression and torsional, are established by using the constitutive model, and the macroscopic mechanical response and texture evolution under different deformation conditions are analyzed. The results show that the strain hardening phenomenon and texture density level increase with the increase of strain in the process of tensile deformation, and the texture type changes with the increase of strain during compression, but the texture density level is basically unchanged. In the torsional process, when the torsional strain is small, there is no texture. With the increase of strain, the texture gradually appears, which is because the deformation is small and the internal deformation of the cylinder along the radial direction is small, so the texture is not obvious.
【作者单位】：北京科技大学机械工程学院;宝山钢铁股份有限公司;
【基金】：国家自然科学基金项目51105029和51575039 国家自然科学基金委员会与中国工程物理研究院联合基金项目U1330121 非线性力学国家重点实验室开放基金项目LNM201512资助~~
【分类号】：TG142.1

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