基于纳米压痕和晶体塑性有限元模拟的先进高强钢力学性能辨识

Identification of mechanical properties of AHSS based on nano-indentation and CPFEM simulation

针对双相钢DP980,采用纳米压痕实验、晶体塑性有限元模拟和基于遗传算法的反分析法,辨识其组成相铁素体和马氏体的细观力学性能。首先借助纳米压痕实验获得两相不同取向单晶的纳米压痕力学数据,通过EBSD和原子力显微镜获得单晶的取向和压痕形貌信息,提取形貌轮廓的特征数据。然后通过CPFEM模拟和反分析方法确定铁素体相和马氏体相<111>{110}和<111>{112}两个滑移系的加工硬化行为和材料参数。通过对比模拟和实验结果,验证了所辨识的滑移系硬化方程和材料参数的可靠性。研究方法亦可以用于其它金属材料的细观力学行为和材料参数的辨识。

Aiming at the dual-phase steel DP980,nano-indentation experiments,crystal plasticity finite element model(CPFEM)simulations and the inverse analysis method based genetic algorithm were used to identify the micro-mechanical properties of the constituent phases ferrite and martensite of DP980.Firstly,nano-indentation experiment was used to obtain the mechanical data of nono-indentation of single crystals with two different-oriented phases;EBSD and atomic force microscope(AFM)were employed to characterize the crystallographic orientation of the indented crystals as well as the morphological profile of the indented regions;then the work hardening behavior and material parameters of the slip systems<111>{110}and<111>{112}for both ferrite and martensite phases were determined by means of CPFEM simulation and the inverse analysis method.By comparing the simulation and experimental results,the reliability of identified slip system hardening equation and material parameters was verified.The method can also be applied to identify the micro-mechanical behavior and material parameters of other metal materials.