A crystal plasticity based finite element (CPFE) framework is developed for performing representative volume element (RVE) calculations on two-phase materials. The present paper investigates the mechanical response and the evolution of microstructure of dual-phase (DP) steels under uniaxial tensile loading, with a special focus on void nucleation. The spatial distribution and morphology of the ferrite and martensite grains in DP steels are explicitly accounted for by generating three-dimensional RVEs with Voronoi tessellations. The effects of microstructural parameters—the volume fraction, morphology and spatial distribution of the martensite phase, and the grain size and orientation distribution of the ferrite phase—on the initiation and spread of localized plastic deformation (leading to void nucleation) are investigated in detail. The soft ferrite phase is modelled by a local crystal plasticity theory with anisotropic elasticity, and the hard martensite phase by the J2 flow theory with isotropic elasticity. The developed CPFE framework successfully predicts both the overall and the local mechanical response, and is perfectly capable of distinguishing between different void nucleation mechanisms experimentally observed for DP steels.

开发了基于晶体塑性的有限元（CPFE）框架，用于对两相材料进行代表性的体积元（RVE）计算。本文研究了双相（DP）钢在单轴拉伸载荷下的力学响应和微观组织的演变，特别关注空隙形核。DP钢中的铁素体和马氏体晶粒的空间分布和形态是通过产生具有Voronoi镶嵌的三维RVE来明确说明的。详细研究了微观结构参数（马氏体相的体积分数，形态和空间分布，以及铁素体相的晶粒尺寸和取向分布）对局部塑性变形的起始和扩展（导致空核）的影响。 。软铁氧体相通过具有各向异性弹性的局部晶体可塑性理论建模，硬质马氏体相通过具有各向同性弹性的J2流动理论建模。发达的CPFE框架成功地预测了整体和局部机械响应，并且完全能够区分实验观察到的DP钢不同的空核机制。