点焊熔核尺寸及焊接电流逆过程设计

Inverse design of spot welding nugget sizes and current parameters

提出了点焊接头的逆过程设计方法,根据力学性能要求确定合格熔核的形状尺寸参数,据此构建数值模型,通过模拟计算确定形核所需的电流参数。采用三种规则形状的点焊熔核受拉伸应力的模型,研究点焊焊接结构的力学性能与熔核尺寸的关系,通过分析不同形状熔核的应力云图和拉伸应力随熔核半径、焊透率变化的关系,对熔核形状进行选择与评价;模拟分析出应力分布均匀,应力集中小的熔核形状,利用有限元方法对球台形熔核进行反向模拟计算,得到了形核所需的焊接电流曲线。

In order to made the physical dimension of nuggets meet the needs of mechanical properties, the inverse design of welded joint is introduced. Based on the mechanical properties, the qualified nugget sizes are determined. According to these, the numerical model is created. Through simulated calculation, the current parameters can be determined. Three kinds of regular shape nugget are used to research the relation between the mechanical properties and nugget sizes. Based on the stress graph, the diameter of nugget and the penetration rate varying with the tension stress, the nugget shapes are evaluated, the one which the stress distribution is the most evenly and the stress concentration is the most little is selected. According to the physical dimension of the nugget, the current parameter curve used for forming nugget is simulated by finite element simulate method.