借助大型非线性有限元Marc软件,应用二维轴对称弹塑性有限元法分析了铍铜管固定短芯头拉拔过程中外模半锥角对轴向应力、拉拔力、摩擦力和轴向残余应力的影响;在此基础上并对外模半锥角进行了优化.结果表明:外模半锥角对铍铜管的轴向应力分布影响不大,而对拉拔力影响显著;随外模半锥角增大,内外表面的摩擦力均减小;当外模半锥角为14°或12°时,拉拔力很小,同时内外表面的轴向残余应力较小,而且内外表面残余应力差也较小,拉拔后的铍铜管精度和质量都较高;从多因素考虑,选择外模半锥角为12°较14°更合理,并且拉拔试验结果与模拟结果基本吻合.

In virtue of large-scale nonlinear finite element software Marc,the finite element method of two-dimensional axial symmetry elasticity and plasticity was used for analyzing the influence of half-cone angle of external mold on axial stresses,pulling force,friction and axial residual stresses in pulling process of fixed short rod of beryllium bronze tubing.The results indicate that the axial stresses distributing in the beryllium bronze tubing was hardly influenced by the half-cone angle of external mold.But this angle had distinct influence on pulling force.Maximum friction force of the inner and outer surfce both decreased with the increase of half-cone angle of externd mold.When the half-cone angle was 12°or 14°,the pulling force was small and the inner and outer axial residual stresses were also relatively small.Further more,The numerical value difference of residual stresses of the inner surface and outer surface hod only slight change.Quality and precision of beryllium bronze tubing were comparatively fine.Considering different factors,choosing the half-cone angle of external mold of 12° is better than the angle of 14°.The pulling test and simulation were basically consistent with the data.