Abstract: The elastic-plastic equations of Timoshenko beam based on weak-form quadrature element method is established by deformation theory and solved by employimg the whole amount method of initial stress.The plastic analysis program of the clamped,layered steel beam corss-section is given.Compared with the commercial finite element software MIDAS,the results verified the validity of the method and showed that compared with the finite element method,for the weak form quadrature element method was applie...