Papers by Keyword: Failure Mechanics

Abstract: Among the different test methods to characterize the fibre/matrix interfacial shear strength, the fragmentation test is one of the most simple in terms of experimental setup and the amount of data that can be extracted from one single test. In this work, the fragmentation test method was implemented to assess the interface shear strength obtained for a single steel filament embedded in an unsaturated polyester resin.. The fragment lengths were discriminated and processed using the Kolmogorov-Smirnov and Chi-square fitting test methods showing that the fragment lengths correspond to the extreme statistical distributions. In addition, a very high shear strength (67MPa) of the steel/polyester interface was estimated using the Kelly and Tyson criteria considering the critical fragment length.

Abstract: FE models of both the single-layer Kiewitt reticulated domes and the impactor were developed incorporating ANSYS/LS-DYNA. Three failure modes for Kiewitt reticulated dome under impact load are discerned. Moreover, Global collapse of structure belongs to the progressive collapse, and is the most serious failure. After this, stress of members, velocity and strain energy of each component are introduced to display the progressive process of collapse. It shows that the dome does not defend impact load as a whole. Each component of structure is impacted and dented in turn. And the collapse enlarges from impact zone to the supports of dome. Furthermore, collapse relates to energy transform among kinetic energy, stain energy and potential energy of structure. Moreover, collapse will continue, if initial kinetic energy and release of potential energy of structure exceed the strain needed.

Abstract: Based on the stress characteristics of freeze shinking shaft lining at construction and operation stages, it is set up that The anisotropic damage model including initial damage, which suit to make Damage and Fracture Mechanics analysis for the shaft lining. A 3 dimensional anisotropic damage program is compiled using FEPG software, which take the following factors into consideration: temperature, conduction conditions, concrete facture energy and its aggregate gradation. Take the liangbosi mine shaft lining for example, its damage evolutionary process under complicated stresses such as permanence field stress, the gravity and vertical additional stress changed with time is obtained. It is discussed that the facture’s position and its development process, and the mechanical mechanics of the shaft lining structure failure.

Abstract: Suitable testing arrangements are made for assessing the strength of welded T-joint specimens and providing input for the validation of finite element simulations of their behaviour under load. Material characterisation across the various weld areas is carried out through tensile and hardness tests as well as standard metallographic procedures for examining the microstructure. Strain is measured at critical locations identified through initial FEM analysis. Failure mechanisms are monitored, failure loads recorded and linked to the joint material and geometric characteristics. The consistency of FEM predictions with these measurements and observations provide a reasonable degree of confidence that the developed model can yield reliable stress and strain distributions for failure analysis.