薄壁铝合金弯管差温成形数值模拟研究

Research on Numerical Simulation of Differential Temperature Forming for Thin-Walled Aluminum Alloy Bent Pipes

摘要: 薄壁弯管作为气、液输送的管道广泛地应用于航空航天、石油、电力等领域。为解决铝合金管成形中易出现的外侧破裂和内侧起皱等缺陷，本文采用推弯工艺有限元模型数值分析方法，探究了成形温度条件、差温区域分布及加热区温度对推弯成形质量的影响规律。结果表明：相较于常温成形工艺，热–力耦合差温成形工艺可显著改善壁厚分布的均匀性，当差温区域分布位置为r2与冷却区为c2时，成形质量最好，当冷却区固定为室温20℃时，400℃加热条件下等效塑性应变分布最均匀。

Abstract: Thin-walled bent pipes are widely used as gas and liquid transmission pipelines in aerospace, petroleum, electric power and other fields. To solve the defects such as outer wall fracture and inner wall wrinkling that are prone to occur during the forming of aluminum alloy pipes, a numerical analysis method based on the finite element model of the push-bending process was adopted to investigate the influence laws of forming temperature conditions, differential temperature zone distribution and heating zone temperature on the push-bending forming quality. The results show that compared with the room temperature forming process, the thermo-mechanical coupled differential temperature forming process can significantly improve the uniformity of wall thickness distribution. The forming quality is optimal when the differential temperature zone is set as r2 and the cooling zone as c2. When the cooling zone is fixed at room temperature (20˚C), the equivalent plastic strain distribution is the most uniform under the heating condition of 400˚C.