超塑性圆板自由胀形过程的反向模拟方法

 提出一种超塑性圆板自由胀形过程的反向模拟方法,由此可以按胀形件要求的壁厚均匀性确定原始坯料的厚度分布。讨论了胀形过程的各种因素对原始坯料厚度分布的影响;提供了保证获得均匀壁厚胀形件的原始坯料厚度的估算公式,可供设计采用。

A BACKWARD SIMULATION METHOD FOR SUPERPLASTIC BULGING OF THE CIRCULAR BLANK OF SHEET METAL

A backward simulation method is proposed for superplastjc bulging of the circular sheet metal blank. It is a difficult problem to obtain workpiece with uniform thickness for superplastic bulging processes. The geometry and dimensions of the initial blank can be determined, by the proposed method to guarantee the desired thickness uniformity. The influence of the process variables on the geometry and dimensions of the initial bland is also investigated by using the method presented in the paper. The analytical results indicate that the distribution of the relative thickness S* is only dependent on the relative height H* and the strain rate sensitivity m. The Larger the relative height, the smaller the strain rate sensitivcty m, the worse the blank thickness uniformity. Based on the calculated results, a formula for determining the dimensions of the initial blank is derived.