【摘要】 目的 研究铝/钢薄板无铆连接过程中接头形貌的影响因素。方法 采用有限元模拟方法分析了铝/钢薄板在平底模具下接头形貌的成形过程。结合变形区域的金属流动情况，解释了互锁结构的形成机理，并分析了不同工艺参数对接头形貌的影响。结果 接头互锁结构主要是依靠铝板填充钢板的凹陷部位而形成的，抑制钢板与模具接触一侧的金属流动有助于接头底部和侧壁的钢板拉薄，进而形成内部凹陷，促进互锁结构的形成。摩擦因数对接头形貌参数影响较大，增大摩擦因数可显著提高接头的互锁量。结论 冲头半径、冲头圆角、凹模深度以及摩擦因数对颈厚值和互锁量均有显著影响。通过控制这些影响因素，可以得到良好的接头。此外，接头的失效形式以铝板颈厚较薄处的剪断失效为主，因此对于采用铝上钢下的无铆连接，保证颈厚值相对于互锁量更加重要。更多还原

【Abstract】 The work aims to study the affecting factors on morphology of joint of steel/aluminum sheet in mechanical clinch.The forming process of joint morphology of steel/aluminum sheet in flat bottom die was simulated by finite element method.The formation mechanism of interlocking structure was explained based on the metal flow in each region, and the effect of different process parameters on morphology of joint was analyzed. The interlocking structure of the joint was mainly formed by filling the concave part of the steel sheet inside the joint with aluminum sheet. Inhibiting the metal flow on the side of the steel sheet in contact with the die was conductive to thinning the steel sheet at the bottom and the side wall of the joint, thus forming the internal concave and promoting the formation of the interlocking structure. The friction coefficient had a great effect on the morphology parameters of joint, and increasing the friction coefficient could significantly improve the interlocking quantity of joint. The punch radius, punch fillet, die depth and friction coefficient all have a significant effect on the neck thickness and the interlocking quantity. By controlling these affecting factors, a good joint can be obtained. In addition, the failure mode of the joint is mainly the shear failure at the thinner neck of the aluminum sheet. Therefore, for the mechanical clinch with the aluminum sheet at top and the steel sheet at bottom, it is more important to ensure the neck thickness than the interlocking quantity.更多还原