(西北工業(yè)大學(xué) 凝固技術(shù)國家重點(diǎn)實(shí)驗(yàn)室 材料學(xué)院，西安 710072)
摘 要: 為了控制矩形管繞彎成形的回彈和截面變形，建立考慮壓塊力、速度加載條件的回彈和截面變形有限元預(yù)測模型，并對其可靠性進(jìn)行實(shí)驗(yàn)驗(yàn)證。基于所建模型研究壓塊的摩擦因數(shù)、夾持壓力和助推速度對H96矩形管回彈與截面變形的影響規(guī)律。結(jié)果表明：摩擦因數(shù)和夾持壓力越大，回彈角和橫截面高度變形越小。但壓塊對橫、縱截面畸變的作用完全相反；芯頭支撐區(qū)域內(nèi)助推速度的變化能夠影響回彈量，且不會加劇截面變形。提出變助推速度的壓塊邊界條件組合方案，實(shí)現(xiàn)了彎曲角度小于90°和大于等于90°彎管的回彈量分別降低55.31%和36.45%，60°彎管的高度變形量平均降低1.79%，90°和120°彎管的高度變形量最大分別降低5.98%和6.35%。
關(guān)鍵字: 繞彎成形；H96矩形管；回彈；截面變形；工藝參數(shù)；有限元模擬
（State Key Laboratory of Solidification Processing, School of Materials Science and Engineering,
Northwestern Polytechnical University, Xi’an 710072, China）
Abstract:In order to control springback and section deformation of rotary-draw bending of rectangular tube, the finite element model for springback and sectional deformation prediction, which considers the loading and velocity conditions of pressure die, was established and verified by experiment. Based on the model, the impact of friction coefficient, pressure and boosting velocity of pressure die on springback and section deformation of H96 rectangular tube was investigated. The results show that the larger the friction coefficient and the clamping pressure are, the smaller the springback angle and the cross-section height deformation are. However, the impacts of pressure die on deformations of cross-section and longitudinal-section are completely opposite. The change of boosting velocity within core-filled area can influence the springback amount, while not exacerbate section deformation at the same time. Then, the combinations of pressure die boundary conditions of variable boosting speed were proposed. And by which, it is realized that springback angles are decreased by 55.31% and 36.45%, respectively, for bent tubes smaller than 90° or no less than 90°. The cross-section height deformations are reduced by 1.79% for 60° tube on average, and 5.98% and 6.35%, respectively, for 90° tube and 120° tube at most.
Key words: rotary-draw bending; rectangular H96 tube; springback; section deformation; process parameters; finite element simulation
