【摘要】 采用基于ABAQUS建立的中强TA18钛合金厚壁管数控弯曲有限元模型,研究了不同配合参数条件下中强TA18钛合金厚壁管数控弯曲过程中的壁厚变化和截面扁化行为,确定了适合于中强TA18厚壁管数控弯曲的压力模、弯曲模与管材间隙和摩擦的选取原则。结果表明,压力模和弯曲模与管材的间隙,对壁厚增厚率的影响较减薄率的影响显著,过大的压力模与管坯间隙会造成内侧小凸包缺陷,过大的弯曲模与管材间隙会造成外侧壁的严重塌陷。因此,弯曲模和压力模与管材的间隙应取较小的值;压力模和弯曲模与管材间的摩擦,对壁厚变化和截面扁化影响不大,因此,压力模和弯曲模与管材间可选用航空润滑油或拉深油进行润滑。更多还原

【Abstract】 The deformation behaviors of the wall thickness variation and cross-sectional flattening in the NC bending of medium-strength TA18 thick-walled tubes under different contact conditions between tube and dies were investigated using a 3D elastic-plastic finite element model established based on ABAQUS.The election principles of the friction and the clearance between pressure die or bending die and tube in NC bending of a medium-strength TA18 tubes were determined.The results show that:the effects of the clearance between pressure die or bending die and tube on the thickening ratio is larger than that on the thinning ratio.A larger clearance between the pressure die and tube will lead an inside bulge to occur,and a larger clearance between the bending die and tube will make a severe inward collapse of outside wall.Therefore,the clearance between pressure die or bending die and tube should decrease as soon as possible.The effects of the friction between pressure die or bending die and tube on the variations of wall thickness and cross-section in NC bending of TA18 tubes is small,thus aviation lubricating oil or draw oil can be used to lubricate the interface between pressure die or bending die and tube.更多还原