管材的回转牵引弯曲试验及回弹分析

为了提高管材精确弯曲质量,在弯曲实验及有限元模拟的基础上,利用理想弹塑性变形模式,分析了管材回转牵引弯曲过程中产生的回弹现象.因弯管各部分变形程度不同,产生了由弹性弯曲和塑性弯曲引起的两种回弹.通过理论分析导出近似计算公式,并利用部分实验结果对公式进行了相应验证.结果表明,理论计算值略小,其原因与试验中所施弯曲力不均匀和没有计入摩擦的影响有关.经过大量实验修正后可望应用于生产实践.

Experiments and Analysis on the Spring-Back in Rotary-Drawing Tube Bending

In order to improve the quality in accurate tube bending, the spring-back of rotary-drawing tube bending is analyzed by the adoption of idealized elastic-plasticity deformation model, based on bending experiments and finite element simulations. Due to differences degrees of in deformation in different parts, two kinds of spring-back, created respectively by elastic-bending and plastic-bending, are generated. Through theoretical analysis, approximate formulas of spring-back are deduced, as are verified by making use of partial tube-bending experiments. The reason why the theoretical calculated values are smaller than those given by experiments is related to the nonuniformity in the bending force and in disregarding influence of friction. The formula is expected to be useful in practice through further amendment of more experiments.