【摘要】 为优化铜管空拔工艺参数和提高工件加工质量,应用大型有限元分析软件ANSYS中的LS-DYNA求解器模拟了某规格铜管的空拔成形过程,得到了管件成形过程中任一时刻主要场量的分布云图,分析了成形过程中管件的变形和应力的特点,研究了摩擦力和模具锥角等因素对空拔力与管件伸长率的影响规律。数值模拟分析表明:在应变分布上,管件轴向和周向的最大塑性变形主要发生在管件与模具初始接触处与减径区;在应力分布上,轴向应力和径向应力随管件在模具中的位置不同而有较大差异,在壁厚方向上由管件的外表面到内表面其应力依次为拉应力和压应力,且最大压应力出现在减径区,而最大拉应力则出现在定径区连接处。在管件拉拔力的变化规律上,降低摩擦力和合理的模具锥角能使拉拔力控制在最小范围内。在管件伸长率的变化规律上,较大的摩擦力和模具锥角能使管件的伸长率增大。更多还原

【Abstract】 In order to optimize the process parameters and improve the product quality,the drawing process of a certain copper tube is simulated by finite element software ANSYS/LS-DYNA.The distributing nephogram of the main field mete at any time during the drawing is obtained,and the deformation and stress characteristic are analysed.The effects of friction and the mould prick angle on the drawing and tube elongation ratio are examined.The numerical simulation results show that:(1) the axial strain and the circumferential strain increase with an increase of the tube′s axial displacement in the die,and the maximums of them all appear at the joint between reducing straight and calibrating straight;(2) the axial stress and the circumferential stress is much different for different displacement in the mould,and the maximums of them all appear at the joint between reducing straight and calibrating straight;in the direction of the tube wall,from the exterior surface to the interior surface,its stress is strain and pressure in turn;(3) the drawing force can be controlled within the minimum range by reducing the friction and using the reasonable prick angle;(4) for the tube elongation ratio,larger friction and mould prick angle can make the tube wall thick after being drawn.更多还原