管材弯曲中应力中性层位移计算与影响因素分析

摘要

To study the displacement and influencing factors of the stress neutral layer in tube bending, the stress-strain discipline is analyzed based on the plastic theory. Then the approximate formula of the stress neutral layer displacement is deduced with the consideration of the wall thickness variation and the material hardening characteristics. Finally, to discover the sensitivity factors of the stress neutral layer displacement, the orthogonal design method is introduced. It is considered that the relative bending radius and the hardening exponent has significant effects on stress neutral layer displacement, while the other parameters are not obvious. The comparison of theoretical calculations and numerical simulation results prove the correctness and validity of the theoretical analysis.%为研究管材弯曲成形过程中应力中性层位移及影响因素，基于塑性力学全量理论，分析了管材弯曲的应力应变规律，在考虑材料硬化特性和壁厚变化的情况下推导出应力中性层位移的近似计算公式，并利用正交设计法对应力中性层位移的影响因素进行了敏感性分析，认为相对弯曲半径和硬化指数是影响应力中性层位移最敏感的因素，其它参数无显著影响。通过与数值模拟结果对比，证明了理论分析的正确性和有效性。