基于自由胀形的弯曲管材变形行为

随着制造业轻量化的发展趋势,复杂弯曲异形充液成形管件的应用日益广泛。为了更好地研究弯曲异形复杂管件在充液成形过程中的变形规律,进行可靠的工艺设计。本文通过结合薄膜理论和塑性变形理论对弯曲管件在自由胀形状态下的应力应变进行了理论解析,并通过有限元(FE)分析对理论计算模型进行了验证。FE分析结果与理论模型基本吻合。同时分析了管材在绕弯过程的硬化行为,并探索了在不同的弯曲硬化状态下弯曲管材在自由胀形过程下的破裂位置的规律,并且用实验进行了验证,实验结果与FE分析结果吻合。

Deformation behavior of a bent tube based on free expansion

As the development of lightweight design in manufacture industry,the application of thinwalled bent hollow tubes with various sections is expanding widely.In order to study the deformation behavior of bent tubes during hydroforming process and have a reliable process design,a theoretical model of free-expansion bent tubes based on membrane theory and plastic theory was put forward,and the model was verified by finite element (FE) analysis.The FE analysis results show good agreement with the theoretical model.The stresses distribution and deformation behavior were revealed.Finally,the work-hardening behavior during rotary draw bending was analyzed,and meanwhile,the fracture site of pre-bent tubes with different work-hardening states during free-expansion process was explored.The experimental results show good agreement with the FE analysis results.