摘要
针对超薄板焊后面外失稳变形的机理以及矫正的研究目前仍较少。以厚度为0.07 mm的不锈钢金属箔为研究对象,建立基于壳单元的有限元计算模型,采用热-力顺序耦合的方法针对激光焊中出现的波浪变形现象进行数值模拟。波形分布的数值模拟结果与实测基本吻合。分析认为在整个焊缝长度上的焊接应力会在焊接过程中自身平衡,拉伸应力区外会有压应力来平衡,从而产生间隔分布的局部压应力区导致波浪变形出现。发现采用0.15%的预拉伸方法可以大大减少薄板的面外失稳变形量,其主要原因是焊后焊缝中的塑性应变发生了由压缩向拉伸应变的转变。采用滚轴碾压可以矫正焊缝处的波浪变形,随焊碾压可以使超薄板焊后整体面外变形幅度降低,由原来的0.46 mm下降至0.25 mm,直径72 mm滚轴碾压后焊缝处波浪变形高度差被基本控制在0.002 mm之内,接近平直。研究结果对提高超薄板结构的焊接质量具有积极的参考价值。
At present, there is still little research on the mechanism and correction of external instability deformation after ultra-thin plate welding. A finite element model based on shell element was established to analyze the wave deformation of 0.07 mm thick stainless steel foil caused by laser welding. A thermal-mechanical sequential coupling analysis was conducted. The waveform distribution of simulation was in good agreement with the experiments. The welding stress on the whole weld length will balance itself in the welding process, and there will be compressive stress outside the tensile stress zone to balance, resulting in interval distribution of local compressive stress zone and wave deformation. The out-of-plane instability deformation of the foil was greatly reduced by using 0.15% pre-stretching method. The main cause is the transformation of plastic strain from compression to tension in the weld after welding. The wave deformation at the weld can be corrected by roller rolling. The overall out-of-plane deformation of the ultra-thin plate was reduced from the original 0.46 mm to 0.25 mm by rolling. The foil was close to flatness after rolling the diameter 72 mm roller. The height difference of wave deformation at the weld was basically controlled within 0.002 mm. The research results have positive reference function for improving the welding quality of ultra-thin plate structure.
作者
张景祺
相志磊
王细波
雷永平
林健
ZHANG Jingqi;XIANG Zhilei;WANG Xibo;LEI Yongping;LIN Jian(Faculty of Materials and Manufacturing,Beijing University of Technology,Beijing 100124;Taiyuan Aero-Instruments Co.,Ltd.,Taiyuan 030006;Beijing Institute of Astronautical System Engineering,Beijing 100076)
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2022年第4期72-79,共8页
Journal of Mechanical Engineering
基金
北京市自然科学基金(3212001)
国家重点研发计划(2017YFB1104803)
国家自然科学基金(51005004)资助项目。
关键词
波浪变形
有限元模拟
随焊碾压
预拉伸
wave deformation
finite element analysis
rolling
pre-tension
