Accession Number : AD0473367


Title :   DEVELOPMENT AND EVALUATION OF ENERGY SEARCH METHODS OF NONLINEAR STRUCTURAL ANALYSIS.


Descriptive Note : Final rept. 1 Aug 63-1 Jun 65,


Corporate Author : CASE INST OF TECH CLEVELAND OH


Personal Author(s) : Bogner, F K ; Mallett, R H ; Minich, M D ; Schmit, L A


Report Date : Oct 1965


Pagination or Media Count : 183


Abstract : Mathematical models in the form of potential energy functions are derived for truss, frame and plate discrete elements. Geometric non-linearities are directly incorporated within the discrete element representations to provide for the occurrence of local buckling and to allow detection of general instability. All of the displacement modes employed assure interelement compatibility, as well as intraelement compatibility, which is fundamental to the principle of minimum potential energy. The direct solution of the potential energy formulation is presented as an alternative means of attacking the nonlinear structural analysis problem. The potential energy formulation of a structural system of discrete elements is constructed simply by summing the energy contributions of the individual elements. Mathemaical programming methods of unconstrained minimization are employed in the direct search of the energy function. The goal of the search is to find the stationary point which is equivalent to the solution to the direct formulation. The application of the Reissner energy principle to a structural problem characterized by both geometric and nonconservative material nonlinearities is explored. Specifically an investigation designed to explore special characteristics of this approach is reported. (Author)


Descriptors :   *STRUCTURES , NONLINEAR SYSTEMS , BUCKLING , ENERGY , OPTIMIZATION , DEFORMATION , CONTROL , STATICS


Distribution Statement : APPROVED FOR PUBLIC RELEASE