将fcc金属滑移和孪生 2种机制综合起来进行考虑 ,应用Bishop Hill最大功原理 ,计算和分析了临界剪切应力之比 ζ不同时各理想取向平面共生变形时的屈服应力状态、相应活化系及Taylor因子M .结果表明 :当 ζ >1 /3时 ,随着 ζ的减小 ,C ,G ,RCu3种取向时的M值不变 ,共同的活化系均为滑移系 ,不易孪生 ;其它取向的M值越来越小 ,共同的活化系均包括滑移系和孪生系 ,具有孪生倾向 .ξ取不同值时 ,最强和最弱的M值的取向位置均没有改变 ,分别位于RG 取向处和C ,G取向处 . Based on the Bishop Hill principle of maximum work, the yield stress state under the symbiotic deformation of each ideal orientation plane with different ratio of critical shear stress ζ was calculated. The corresponding activation system And Taylor factor M. The results show that with ζ> 1/3, with the decrease of ζ, the values ​​of M in C, G and RCu orientation are unchanged, and the common activation system is slip system, which is not easy to twin; The values ​​of M in other orientations are getting smaller and smaller, and the common activation system includes both slip system and twin system, with twins tendency.When different values ​​are taken, the orientation positions of the strongest and weakest M values ​​are unchanged, RG orientation and C, G orientation.