层合轧压SMAT纳米化304不锈钢复合材料的渐进损伤模拟

基于表面机械研磨处理技术(SMAT)和温轧工艺,可以加工出具有高强度和理想韧性的层合纳米化结构复合材料。为了研究层合轧压SMAT纳米化304不锈钢的变形行为以及随后的损伤起始与演化过程,采用内聚有限元方法,建立了用于预测该复合材料力学性能的有限元模型。基于这个模型,评估了材料中纳米晶层性质,包括法向内聚强度、切向内聚强度、损伤演化断裂能和体积含量对于材料整体强度和韧性的影响。通过数值仿真结果和实验结果的比较,验证了模型的合理性和准确性,同时预测结果表明增加纳米晶层的内聚强度和减小其断裂能都能提高材料的韧性;增加纳米晶层的体积含量,材料的整体韧性降低,但是强度会增加。

Progressive damage simulation of layered co-rolled SMATed 304SS composite

Based on the techniques of surface mechanical attrition treatment (SMAT) and warm co-rolling, laminated and nanostructured composite materials with high strength and exceptional ductility could be produced. In order to study the deformation behavior and associated damage initiation/evolution process in the layered co-rolled SMATed 304 stainless steel (SS), cohesive finite element method (CFEM) was employed to generate the model which could be used to predict the mechanical properties of this composite. Based on the model, the effects of nanograin layer properties such as normal cohesive strength, tangential cohesive strength, fracture energy and volume fraction on the overall strength and ductility was investigated in this paper. The comparison between simulation result and experiment result demonstrates that the model produced is reasonable and accurate. Meanwhile, results predicted indicate that the ductility of composite material increases with the increase of nanograin layer cohesive strength and the decrease of nanograin layer fracture energy. With increasing the volume fraction of nanograin layer, the ductility of composite material reduces, but the strength increases.