使用柔性垫层是抑制和消除多点模拉形过程中零件表面缺陷的重要措施。针对常规橡胶垫层的不足,提出了一种以橡胶为基体以金属板条为加强结构的复合结构垫层,对其进行了有限元建模和分析,并从垫层变形控制角度对加强结构的设计参数进行了优化。分析结果表明,加强结构中金属板条宜薄不宜厚,但厚度太薄则无法有效抑制零件的表面缺陷,应控制在0.5mm左右。而较宽的加强材料的宽度也有利于提高垫层的性能,但过宽的板条会影响垫层的贴模能力,应控制在钉杆截面宽度的80%左右。
Using flexible interpolator pad is an important method to suppress the part surface defect in stretch-forming process for reconfigurable tool. This paper aims at the shortcomings of conventional pure rubber pad, and designs an interpolator pad with composite structure, which taken rubber as the base and sheet metal bar as the reinforcement. FEM analysis and optimization are made on the parameters of reinforcement structure according to pad deformation control. The results show that, reinforcement bar of less thickness or more width works better, but less than 0.5 mm thickness are unable to avoid part surface defect, and bar of width larger than 80% of pin edge makes the pad too incompliant to touch the tool.