椭圆截面管件充液压制变形与应力分析

发布时间：2018-02-25 20:18

本文关键词： 充液压制圆管压制内高压成形预成形壁厚分布　出处：《机械工程学报》2017年18期 　论文类型：期刊论文

【摘要】：预成形是内高压成形的关键工序,预制坯的形状直接影响到后续内高压成形的缺陷与壁厚分布。针对管件无内压支撑压制时因失稳导致的预制坯截面凹陷与尺寸不可控等问题,提出管件充液压制成形方法。对椭圆截面管件充液压制成形过程进行应力分析与试验研究,将充液压制与传统压制进行对比,分析充液压力和下压量对管件截面应力、壁厚及尺寸的影响。结果表明:管内充液可有效改善压制管件等效应力分布情况,充液压力越大,等效应力分布越均匀;相比于传统压制,充液压制过程中椭圆截面的壁厚变化并不明显,最大减薄处位于直壁部分中间区域,当充液压力为15 MPa时,其最大减薄率为2%;随着充液压力的增大,管件直壁部分的凹痕缺陷逐渐平复消失。
[Abstract]:Preforming is the key process of internal high pressure forming, and the shape of preform directly affects the defects and wall thickness distribution of subsequent internal high pressure forming. In view of the problems of section depression and uncontrollable size of preform due to unsteady pressing of pipe without internal pressure bracing, the shape of preform directly affects the defects and wall thickness distribution of subsequent internal high pressure forming. This paper puts forward the method of forming tube with hydraulic pressure. The stress analysis and experimental study on the forming process of elliptical cross section pipe are carried out. The hydraulic filling system is compared with the traditional pressing, and the pressure of filling and lowering pressure on the cross section stress of pipe fitting is analyzed. The results show that the distribution of equivalent stress can be improved effectively by filling the tube, and the higher the pressure of filling is, the more uniform the distribution of equivalent stress is. The wall thickness of the elliptical section is not obvious in the process of hydraulic charging. The maximum thinning is located in the middle region of the straight wall. When the filling pressure is 15 MPa, the maximum thinning rate is 2, and the maximum thinning rate increases with the increase of the filling pressure. The indentation defects in the straight wall of the fittings gradually flatten out.
【作者单位】：哈尔滨工业大学材料科学与工程学院;哈尔滨工业大学金属精密热加工国防科技重点实验室;
【基金】：教育部长江学者和科技创新团队发展计划资助项目(IRT1229)
【分类号】：TG306

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