10-9 对于图示平面应力状态,各应力分量的可能组合有以下几种-|||-情形,试按第三强度理论和第四强度理论分别计算此几种情-|||-形下的计算应力。-|||-(1) (sigma )_(x)=40MPa (sigma )_(y)=40MPa _(xy)=60MPa;-|||-(2) (sigma )_(2)=60MPa (sigma )_(y)=-80MPa ,_(xy)=-40MPa ;-|||-(3) (sigma )_(z)=-40MPa ,(sigma )_(y)=50MPa ,_(xy)=0;-|||-(4) (sigma )_(x)=0 (sigma )_(y)=0 ,_(xy)=45MPa-|||-σx-|||-Txy-|||-习题 10-9 图