基于热点应力法U型激光焊接夹层板疲劳寿命分析

Fatigue life prediction of laser welded corrugated U type core sandwich panels based on hot spot stress method

U型激光焊接夹层板作为新型船用结构,准确预报其疲劳寿命对于工程应用有着重要的现实意义。本文依据传统焊接结构热点应力外推方法,给出了适合激光焊接夹层板结构的热点应力外推公式,计算了不同外推公式下结构的疲劳寿命,并与已有的试验结果进行对比,最后研究了不同单元层数和焊缝宽度对结构疲劳寿命的影响。结果表明:采用本文的外推公式、外推区域面板厚度方向划分3层单元时,计算结果与试验值较为吻合,验证了热点应力法求解激光焊接夹层板疲劳寿命的有效性;并且结构的疲劳寿命随着焊缝宽度的增加显著提高。

Laser-welded corrugated U type core sandwich panel （ U-LASCOR） is a new type of ship structures, the accurate fatigue life prediction of U-LASCOR has important significance for the engineering application. Based on hot spot stress method, the extrapolation formulae are proposed for U -LASCOR. And the prediction results of fatigue life are compared with the test data from literature. Moreover, the effects of weld width on fatigue life is studied. The prediction results show better agreement with test data based on our formula and three layers of element on the lower panel of U -LASCOR model. The results show the fatigue life is increased with the increasing of weld width.