Method for condensing FETI engineering numerical values based on regional decomposition

The invention discloses a method for condensing FETI engineering numerical values based on regional decomposition. The method comprises the steps of solving a generalized flexibility matrix and a boundary flexibility matrix through constructing a rigid matrix only related to the boundary freedom degree of a floating sub-domain and a rigid body modal matrix of the rigid matrix. The formed new 'hat' matrix can fully utilize and maintain the sparsity of the floating sub-domain rigid matrix, and the order of the new 'hat' matrix is equal to the number of floating sub-domain boundary degrees of freedom and is far smaller than the scale of the original 'hat' matrix, so that the storage space is greatly reduced, and the triangular decomposition solving efficiency of the generalized stiffness matrix is improved; and the calculation of the local flexibility matrix becomes economical and feasible. Meanwhile, an intermediate result of the new 'hat' matrix calculation just provides a Dirichlet preprocessor with a better