Papers by Keyword: Principle of Superposition

Abstract: A Continously Embedded Force Doublet over the Particular Region can be Regardedas the Distributing Eigen Strain. this Fact Implies that many Sorts of Inelastic Strain can Bereplaced by the Force Doublet. in the Present Paper, the Force Doublet is Used to Alter the Localconstitutive Relationship. as a Result, a Method for Analyzing the General Inclusion Problem Inwhich the Material Properties of the Inclusion are Not only Different from those of the Matrixmaterial but also can be even a Function of Spacial Coordinate Variables is Proposed. Thetheoretical Background of the Present Analysis is Explained Followed by some Representativenumerical Results.

Abstract: A key problem in engineering application of “design by analysis” approach is how to decompose a total stress field obtained by the finite element analysis into different stress categories defined in the ASME Code III and VIII-2. In this paper, we suggested an approach to separate primary stress with the principle of superposition, in which the structure does not need to be cut into primary structure but analyzed as a whole only with decomposed load. Taking pressurized cylindrical vessel with plate head as example, the approach is demonstrated and discussed in detail. The allowable load determined by the supposed method is a little conservative than that determined by limited load analysis.

Abstract: When two materials are bonded, the free-edge stress singularity usually develops near the intersection of the interface and the free-surface. Fracture in bonded dissimilar materials may therefore occur from an interface crack which develops at the intersection of interface and free-surface. Free-edge stress singularity is very important in the evaluation of strength of bonded dissimilar materials. In this study, the relationship between the stress intensity factor of a small edge crack on interface of bonded dissimilar materials and the intensity of free-edge stress singularity of bonded dissimilar materials with no crack under external mechanical loading was investigated numerically by using the boundary element method. The relationship was also investigated theoretically by using the principle of superposition. The results of numerical analyses were compared with those of theoretical analyses. It was found that stress intensity factors of small edge crack on interface K1 and K2 were proportional to the intensity of free-edge stress singularity of bonded dissimilar materials Kσ without crack irrespective of the combination of materials. The numerically determined proportional coefficient between K1 and Kσ agreed well with the theoretical one, and was not affected by crack length when proper normalizations were applied. From these results, it is suggested that stress intensity factor of small edge crack on interface can be used as a strength criterion of interface of bonded dissimilar materials.