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本文借助滑移线场的数值解,对平面应变拉拔的力学性态进行了系统的分析.分析表明,在中间摩擦因素及中间收缩率的平面应变拉拔过程中,其收缩率及凹模半锥角对中间静水压力影响最为显著.比较而言,凹模—工作间表面上的摩擦因素对中间平面上的静水压力的影响则较小;在小收缩率的情况下,情况尤其是这样.因此,当收缩率为一定时,为了减小中间平面上静水拉应力,用减小凹模半锥角的办法较减小摩擦会取得更好的效果.对于在平面应变拉拔过程中,滑移线场采取两个应力奇点(包括有两个中心扇形场)的形式时的收缩率的极限范围,在本文中也给出了一组公式,作为对Green与Hill公式的补充.
In this paper, the mechanical properties of plane strain drawing are systematically analyzed by the numerical solution of the slip line field. The analysis shows that in the process of drawing the plane strain of intermediate friction factor and intermediate shrinkage rate, the shrinkage rate and die The half-cone angle has the most significant influence on the hydrostatic pressure in the middle. In comparison, the frictional factors on the surface of the die-workshop have less influence on the hydrostatic pressure on the mid-plane; in the case of a small shrinkage rate, this is especially the case. Therefore, when the shrinkage rate is constant, in order to reduce the hydrostatic tensile stress in the middle plane, reducing the friction by using the half-taper angle of the female mold will achieve better results. For the plane strain drawing process, The limit range of the shrinkage rate when the slip line field takes the form of two stress singularities (including two centered fan fields). In this paper, a set of formulae is also given as a supplement to the Green and Hill formulas.