考虑损伤的热成形淬硬硼钢失效行为建模研究  

Modeling Study on Failure Behavior of Quenched Hot Forming Boron Steel Considering Damage

作　　者：戴明华[1] 胡平[2] 盈亮[2] 陈帅 王永青[1] 韩小强[2] DAI Minghua;HU Ping;YING Liang;CHEN Shuai;WANG Yongqing;HAN Xiaoqiang(School of Mechanical Engineering,Dalian University of Technology,Dalian 116024;School of Automotive Engineering,Dalian University of Technology,Dalian 116024)

机构地区：[1]大连理工大学机械工程学院,大连116024 [2]大连理工大学汽车工程学院,大连116024

出　　处：《机械工程学报》2024年第6期216-226,共11页Journal of Mechanical Engineering

基　　金：国家自然科学基金(51905073、52375310);中央高校基本科研业务费(DUT21JC41)资助项目。

摘　　要：热成形钢淬硬后强度高、韧性差,热成形过程的高温变形损伤会进一步加剧淬硬后材料的断裂失效,导致零部件服役抗撞性能被高估,造成安全隐患等问题。以600℃下淬火得到的淬硬硼钢为对象,研究了高温预应变对淬硬后材料力学性能和失效行为的影响规律,发现高温预应变越大,材料的强度和伸长率越低,并发生明显的韧脆转变现象。设计了5种应力三轴度子样件,通过DIC系统测得其断裂失效应变并结合有限元反算优化方法,获得了4种预应变下淬硬硼钢的失效双曲线和GISSMO损伤失效模型参数。进一步开展了淬硬硼钢帽型梁结构的轴向压溃试验,探究了考虑成形损伤及引入失效模型对结构抗撞性能预测精度的影响。结果表明:只引入GISSMO失效模型可以较好地预测淬硬零部件的失效行为,但其预测值偏高,而耦合热成形预应变历史并引入相应失效模型的联合仿真,对淬硬硼钢结构的抗撞性能预测最佳。Quenched hot-forming steel has high strength and poor toughness.The hot-forming deformation damage aggravates the fracture failure of the quenched material,and further resulting in the overestimation of the in-service crashworthiness of parts,and safety hazards and other puzzles.Taking the hardened boron steel quenched at 600℃as the object,effects of the high temperature pre-strain on the mechanical properties and failure behaviors were studied in deep.It was found that the distinct ductile-brittle transition occurs due to the higher the pre-strain,the lower strength and elongation.Five kinds of stress triaxiality sub-samples were further designed,and their fracture failure strains were measured by DIC system.Combined with the finite element inverse optimization method,the failure hyperbola and GISSMO damage failure model of the quenched boron steel under four pre-strains were obtained.Furthermore,the axial crush test of the hardened hat-shaped structure was developed to investigate effects of considering forming damage and introducing failure model on the prediction accuracy of structural crash performance.Results shows that the only introducing the GISSMO failure model can better predict the failure behavior of quenched parts,whereas the predicted values are overestimated.In comparison,the co-simulation coupled with hot forming pre-strain history and corresponding failure model can improve the predictive accuracy effectively,and the best predictive result on crashworthiness of quenched boron-steel structures can be obtained.

关 键 词：热成形淬硬硼钢 GISSMO 损伤 失效建模 

分 类 号：U465[一般工业技术—材料科学与工程] TG142[机械工程—车辆工程]