Accession Number : AD0866588

Title :   EPAD, A Computer Program for the Elastic-Plastic Analysis of DOME Structures and Arbitrary Solids of Revolution Subjected to Unsymmetrical Loadings.

Descriptive Note : Technical rept. Feb-Nov 69,

Corporate Author : SERVICE BUREAU CORP INGLEWOOD CA

Personal Author(s) : Cappelli, A. P. ; Agrawal, G. L. ; Romero, V. E.

Report Date : FEB 1970

Pagination or Media Count : 125

Abstract : The EPAD computer program determines elastoplastic deformations, stresses, strains and plastic strains within solids of revolution of arbitrary shape subjected to arbitrary pressure and/or concentrated loads. All possible combinations of boundary conditions are permitted consistent with the theory of plasticity. The program is based on the finite element technique using the 'initial strain' approach to simulate the effect of plasticity in the incremental step-by-step method. Incremental stress-strain relationships are derived from the Prandtl-Reuss constitutive equations and the Von Mises yield criterion. Fourier analysis is utilized for the solution of unsymmetric loading conditions. A numerical procedure is developed for solving the coupled equilibrium equations. An iteration algorithm for improving convergence is presented. Numerical examples are compared with analytical results. Additionally, EPAD handles the detailed stress analysis of hemispherical or ellipsoidal thick walled dome structures due to a prescribed value of externally applied pressure. For specific dome geometry the program accepts simple descriptive dimensions and automatically generates all the necessary geometrical data. A capability is provided for convenient input of specialized axisymmetric and unsymmetric nonuniform pressure distribution when using the dome geometry option. (Author)

Descriptors :   (*STRUCTURAL MEMBERS, MECHANICAL PROPERTIES), SHELLS(STRUCTURAL FORMS), ELASTIC PROPERTIES, PLASTIC PROPERTIES, DEFORMATION, STRESSES, STRAIN(MECHANICS), LOADS(FORCES), BODIES OF REVOLUTION, BOUNDARY VALUE PROBLEMS, NUMERICAL ANALYSIS, COMPUTER PROGRAMMING.

Subject Categories : Structural Engineering and Building Technology
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE