Composite Structural Reliability Calculation by Finite Element and Statistical Strength Theory

摘要

The reliability of the structure can be calculated by combining the non-uniform stress distribution of a structure from finite element analysis with the statistical strength theory under two dimensional nonhomogeneous, uniaxial stress limitations. The specimen models with and without notch are the sample structures to illustrate the calculations. The statistical strength of the structure is cast in the standard Weibull form characterized by the structural scale parameter, Beta E and shape parameter, Alpha E which are functions of the material scale shape parameters (Alpha and Beta.) Therefore, this thesis demonstrated that the scale parameter of the structure remains constant for different load magnitude, only the structural geometry and loading condition cause the change of material scale parameter, Beta to the structural scale parameter, Beta E. The results also shows that the degree of uniformity of stress within structural element and the linearity of the load magnitude and stress distribution within the structure affect the accuracy for the calculation.