高强钢拼焊板三点弯曲变形行为及影响因素

 为掌握先进高强度钢拼焊板弯曲变形行为,采用试验和有限元法完成三点弯曲试验。建立拼焊板三点弯曲试验有限元模型,比较试验与仿真结果即载荷-位移曲线,最大误差为10.94%。基于此,分析摩擦系数和板厚比对拼焊板弯曲特征的影响规律。结果表明,拼焊板两侧变形不均匀,且焊缝相对中心位置发生了偏移。拼焊板与模具间的摩擦系数及其板厚比对三点弯曲行为影响显著。摩擦系数增加,最大载荷、最大能量及弯曲应力均增加,焊缝移动量减小,且当减小到一定程度后稳定;板厚比增加,最大载荷、最大能量、弯曲应力和焊缝移动量均不同程度增加。

Deformation behaviors and influence factors of high strength steel tailor welded blank in three point bending test

To understand the bending behaviors of the tailor welded blanks with the base materials of advanced high strength steel, three-point bending tests were conducted using experiment and the finite element method. A finite element model for the three point bending test was established for the tailor welded blanks. By comparing the load-displacement curve from the experimental results with the results from the finite element analysis, the maximum differrence was 10.94%, showing that the results from the finite element analysis well agreed with the test results. Based on the established model, the effects of the friction coefficient and the thickness ratio were probed. Results indicated that the uneven deformation and related weld-bead migration were observed. The influences of the friction between the tools and specimens and the thickness ratio were obvious on the bending behaviors. As the friction coefficient increased, the peak load and the maximum energy as well as the bending stress increased, while the weld-bead migration decreased first and then remained at a certain level when the friction coefficientdecreased to some extent. When the thickness ratio increased, the four aforementioned parameters increased with different degrees.