题目设火车轮缘与钢轨接触点处的主应力为–800MPa、–900MPa、–1100MPa,按第三强度理论,其相当应力为( )。A.100MPaB.200MPaC.300MPaD.150MPa设火车轮缘与钢轨接触点处的主应力为–800MPa、–900MPa、–1100MPa,按第三强度理论,其相当应力为( )。A.100MPaB.200MPaC.300MPaD.150MPa题目解答答案C