Optics & Laser Technology ( IF 5 ) Pub Date : 2019-12-28 , DOI: 10.1016/j.optlastec.2019.106029 Ahmad Aminzadeh , Ali Parvizi , Mahmoud Moradi
Laser welded blanks (LWBs) are semi-finished components typically manufacture by dissimilar materials, thicknesses, shapes, coatings, etc. After butt welding of the primary sheets, the product sheets are subjected to the sheet metal forming process. Formation of the heat-affected zones (HAZ) is typical in LWBs, which possess quite different mechanical properties than the base materials. Recently, laser beam technologies have been widely employed to weld different types of vehicles panels. In this study applying Nd:YAG laser welding, experimental and numerical investigations are carried out to evaluate the effects of process input factors on deep drawing process of LWBs. Laser beam power, welding speed, blank holder force (BHF), material properties, and friction coefficient are considered as process key input parameters. In addition, the laser welding and deep drawing processes were numerically simulated using Simufact Welding and Abaqus/Explicit software, Used the Simorgh supercomputer for heavy modeling calculations. Moreover, drawing depth, weld line movement, and energy absorption are taken into account as process main outputs or objective functions. Besides, using an advanced MATLAB code, multi objective optimization based on genetic algorithm is applied to determine the optimal design input parameters. It is observed that the critical stresses were taken place outside the weld zone and rupture due to high heat input of laser and metallurgical changes of the base metal occur in the pre-softening zone. In addition, the weld line displacement occurs as a result of plastic strain change of the weld joint that causes failure-prone zone creation as well as the adverse wrinkling. By considering weld line displacement and absorbed energy as multi-objective function, the optimal points is 1.15 mm and 0.21 KJ for weld line displacement and absorbed energy, respectively. Good agreement between the simulated and the experimental results revealed that the model would be appropriate for deep drawing of LWB process numerical simulation.
中文翻译:
深拉异种裁缝激光焊接毛坯的多目标拓扑优化;实验和有限元研究
激光焊接毛坯(LWB)是半成品部件,通常由不同的材料,厚度,形状,涂层等制造。在对接原始板之后,对产品板进行钣金成型过程。在LWB中,热影响区(HAZ)的形成是很典型的,其机械性能与基础材料完全不同。近来,激光束技术已被广泛地用于焊接不同类型的车辆面板。在这项使用Nd:YAG激光焊接的研究中,进行了实验和数值研究,以评估工艺输入因素对LWBs深冲工艺的影响。激光束功率,焊接速度,毛坯夹持器力(BHF),材料特性和摩擦系数被视为工艺关键输入参数。此外,使用Simufact Welding和Abaqus / Explicit软件对激光焊接和深冲过程进行了数值模拟,并将Simorgh超级计算机用于重型建模计算。此外,拉深,焊缝运动和能量吸收被视为过程的主要输出或目标函数。此外,使用先进的MATLAB代码,基于遗传算法的多目标优化被应用于确定最佳设计输入参数。观察到,临界应力发生在焊接区外部,并且由于激光的高热量输入而破裂,并且在预软化区中发生了母材的冶金学变化。此外,焊接线位移是由于焊接接头塑性应变变化而导致的,该变化会导致容易产生故障的区域以及产生不利的起皱。通过将焊缝位移和吸收能量视为多目标函数,焊缝位移和吸收能量的最佳点分别为1.15 mm和0.21 KJ。仿真结果与实验结果吻合良好,表明该模型适用于深加工LWB工艺数值模拟。