管材弯曲过程中的弹塑性变形分析

摘要

The deformation during tube-bending process was analyzed on the basis of the basic hypotheses and the model of linear strain-strengthening material. The analyzed results show that there is a small elastic area in the both sides of the symmetric axis of tube cross-section perpendicular to the bending plane, which can influence the spring-back of the bending unloading in some degree; bending tangential stress increase with the decreases of the relative bending radius, the increases of yield strength and elastic modulus; when the value of the relative bending radius is in a low level, the tangential stress tends to increase sharply; according to the value of the bending tangential stress being lower than the one of tension limit, the formula of the minimum relative bending radius can be deduced, in which although the theory-calculated value is a little bit lower than that of experiment, it can be applied to production after modification and improvement.%在管材弯曲变形的基本假设和简单应力状态下的线性强化材料模型的基础上,对管材弯曲进行了变形分析.分析结果表明:弯管横截面上垂直于弯曲平面方向的对称轴两侧存在很小的弹性区,对弯曲卸载后的回弹产生一定影响;弯曲切向应力主要随相对弯曲半径减小、屈服强度和塑性模量增大而增大;在较小相对弯曲半径范围内,弯曲切向应力有急剧上升的倾向;根据弯曲切向应力小于材料拉伸极限的关系,推导出最小相对弯曲半径的计算公式,理论计算值略小于实际试验值,修正并完善后,可应用于生产.