考虑周向波形特性的航空管路弯曲成形起皱理论建模与临界成形半径分析

Theoretical Wrinkling Modeling and Critical Forming Radius Analysis of Aviation Tube Bending Forming Considering Circumferential Waveform Characteristics

针对传统弯曲起皱理论模型忽略管材周向波形特性造成预测精度不高的难题,基于理论推导和参数拟合建立了管材起皱周向波形函数,结合管材弯曲应力特性建立了其成形起皱机理模型,采用有限元仿真以及实验方法验证了该理论模型的正确性。研究结果表明:新建理论模型的管材起皱预测准确度达到了94.5%,较传统模型提高了12%,改善了传统模型预测精度不高的难题;弯曲半径越小,管材越易起皱。工程中为避免起皱,临界弯曲成形半径不应小于1.89倍管道直径。

The variation characteristics of the circumferential waveform of tubes were ignored by the traditional theoretical models of bending wrinkling,resulting in low prediction accuracy.Aiming at such a problem,the circumferential waveform functions of tube wrinkling wave were established based on parameter fitting method and theoretical derivation,the mechanism models of tube bending wrinkling were established in combination with the tube bending stress models.The correctness of the theoretical models were verified through the finite element simulations and experiments.The results show that the prediction accuracy of the new theoretical models for tube wrinkling reaches 94.5%,which is 12% higher than that of the traditional models and solves the problem of low accuracy of the traditional prediction models.In addition,the smaller the bending radius is,the easier it is for the tube to wrinkle.To avoid wrinkling,the critical bending forming radius should not be less than 1.89 times of the pipe diameter.