Accession Number : ADA324433

Title :   Uncertainty in Marine Structural Strength Due to Variability in Geometry and Material Properties.

Descriptive Note : Final rept.,

Corporate Author : NAVAL SURFACE WARFARE CENTER CARDEROCK DIV BETHESDA MD

Personal Author(s) : Ayyub, Bilal M. ; Muhanna, Rafi ; Bruchman, Daniel D.

PDF Url : ADA324433

Report Date : APR 1997

Pagination or Media Count : 86

Abstract : This report describes the development of a prototype computational methodology for the reliability assessment of continuum structures using finite element analysis with instability failure modes. Geometric and material uncertainties were considered in the finite element model. The reliability assessment was performed using Monte Carlo simulations with variance reduction techniques that consisted of the conditional expectation method. According to Monte Carlo methods, the applied load was randomly generated, and finite element analysis was used to predict the response of the structure under the generated loads in the form of a deformation field. A simulation procedure was applied to compare the response with a specified failure definition and failures were then counted. By repeating the simulation procedure several times, the failure probability defined by the specified failure definition was estimated as the failure fraction of simulation repetitions. A parametric study was performed for a stiffened panel strength to illustrate the procedure.

Descriptors :   *COMPUTERIZED SIMULATION, *FINITE ELEMENT ANALYSIS, *FAILURE(MECHANICS), *MARINE ENGINEERING, *SHIP STRUCTURAL COMPONENTS, *IMPACT LOADS, METHODOLOGY, PARAMETRIC ANALYSIS, DEFORMATION, PROTOTYPES, MONTE CARLO METHOD, GEOMETRY, INSTABILITY.

Subject Categories : Marine Engineering
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE