On the selection of trial functions in the methd of weighted residuals

The principles of selecting trial functions in method of weighted residuals (MWR) are discussed by the method of functional analysis and the approximation theory of complex function in this paper. In addition, a detailed discussion is made on completeness. On this basis the concept of basic factor is proposed for the question of combinatorial structures and some basic factors and general combinatorial types of trial functions are deduced. Finally a rectangular stiffened plate is taken as an example for comparative calculation and good results have been obtained.