内高压成形波节管承载特性分析

内高压成形波节管作为目前应用最广换热设备,其变形特点以及成形后承载特性均备受关注.本文通过数值模拟和实验研究的方法,首先分析波节管内高压成形壁厚分布规律、成形精度以及残余应力分布情况,然后分析成形后波节管在承载时,典型区域应力应变分布情况,得出波节管在承受不同载荷时的变形特点.研究结果表明:在内高压成形过程,当整形压力为290 MPa时,成形精度较好,根部过渡区域减薄率达21.63%,且此处残余应力最大.在承载过程,当波节管承受内压力自由胀形时,波节管等效应力的最大值出现在波节根部过渡区域,此处为承载的薄弱区域;当波节管承受轴向压缩和拉伸载荷时,波峰及其附近区域与之对应的产生轴向拉应变和轴向压应变,体现出波节管具备很好的轴向位移补偿能力.

Analysis of carrying capacity for hydroformed corrugated tubes

Numerical simulation and experiments are carried out to analyze the thickness distribution, forming precision and distribution of residual stress of hydroformed corrugated tubes, and then after different loading experiments and simulation for hydroformed corrugated tubes, to obtain the deformation characteristics, the stress and strain distribution during typical region are analyzed. The results show that there will be a better forming precision with the calibration pressure 290 MPa, and the biggest thinning is 21.63% located at the transition region where there is also the biggest residual stress. When pressure is applied on the inner surface of hydroformed corrugated tubes, the weakest region is at the transition region where there is the biggest equivalent stress. When compressive and tensile load are applied on the end of the hydroformed corrugated tubes, corresponding tensile strain and compressive strain occurred at crest region and nearby, which shows that the hydroformed corrugated tubes have better axial displacement compensation capacity.