弯管中性层偏移计算及截面畸变分析  

Calculation of neutral layer displacement and analysis on section distortion in bending tube

作　　者：陈文佳 CHEN Wen-jia(Locomotive&Car Research Institute,China Academy of Railway Sciences Co.,Ltd.,Beijing 100081,China;Beijing Zongheng Electro-Mechanical Technology Co.,Ltd.,Beijing 100094,China)

机构地区：[1]中国铁道科学研究院集团有限公司机车车辆研究所,北京100081 [2]北京纵横机电科技有限公司,北京100094

出　　处：《塑性工程学报》2022年第8期222-229,共8页Journal of Plasticity Engineering

基　　金：中国铁道科学研究院集团有限公司重点课题基金(2019YJ016)。

摘　　要：针对管材弯曲时的截面畸变现象,基于弹塑性变形理论、弹性-幂强化材料模型以及弯曲横截面力平衡条件,建立了管材弯曲变形和中性层偏离分析模型,并推导出截面壁厚变化和中性层偏移量的解析公式,研究了材料力学性能和弯管几何参数等对管材弯曲时中性层偏移的影响规律,并根据材料的各向同性以及塑性强化情况,提出中性层偏移量的简化解析公式。与相关文献中的计算方法以及试验结果比较,本模型由于考虑了材料的塑性强化作用,精度更高。通过对比06Cr19Ni10弯管壁厚测量结果,由于忽略了管材拉伸变形区域的截面收缩,最大壁厚计算值偏大,最小壁厚计算值偏小。通过试验引入截面修正系数后,进一步提高了模型计算精度。Aiming at the section distortion phenomenon in tube bending,an analytical model for bending deformation and neutral layer displacement was established based on elastic-plastic deformation theory,elasticity-exponentiation material model and force balance condition of bending cross-section.The analytical formulas of the change of cross-section wall thickness and neutral layer displacement were derived.The influence of mechanical properties of material and geometrical parameters of bending tube on the neutral layer displacement in the bending was researched and the simplified analytical formulas of neutral layer displacement were proposed according to the isotropy and plastic strengthening condition of material.Compared with the analytical methods and test results in relevant references,the accuracy of the established model is higher because of considering the plastic strengthening effect of materials.By comparing with the measurement results of thickness of 06Cr19Ni10 bending tube,the calculation value of the maximum wall thickness is higher and the calculation value of the minimum wall thickness is lower due to the neglection of section shrinkage in stretching deformation zone.The calculation of the model is further improved by introducing the section correction coefficient by tests.

关 键 词：管材弯曲 塑性强化 截面畸变 中性层偏移 

分 类 号：TG301[金属学及工艺—金属压力加工]