The formulas for calculating plastic limit load of pipes with circumferential surface crack, embedded crack and through wall crack under combined load of tensile force, asymmetrical bending moment and internal pressure are presented.

In this paper,the inversable matrix solution of a kind of real matrix equation X~△AX=A is considered,where A is a inversable bisymmetric matrix,X~△is bisymmetric transposed matrix of X,and their general solution forms are derived; the bisymmetric solution of a kind of real matrix equation XAX=A is considered,and their general solution forms are derived too.

By this iterative method,the least squares bisymmetric solution can be obtained within finite iterative steps in the absence of round off errors,and the solution with least norm can be got by choosing a special initial bisymmetric matrix.

This paper has discussed the generalized inverse eigenvalue problem of centrosymmetric matrix,anti-centrosymmetric matrix and bisymmetric matrix.

Least-square solutions of inverse problems for bisymmetric matrices;

Least-squares solution for the inverse problem of real matrices、symmetric matrices and bisymmetric matrices are studied in this thesis.

thesis and mainly discuss the following problems:What we mainly discussed in the second chapter as follows:(1) S1,S2 are sets of symmetric orth-symmetric matrices;(2) S1,S2 are sets of bisymmetric matrices;(3) S1,S2 are sets of anti-.