Papers by Keyword: Cracking Propagation

Abstract: This paper reports the results on cracking propagation and pattern of reinforced concrete (RC) beam conducted using irregular-shaped Polyethylene Terephthalate (IPET) as a fibre. Three volume fraction of IPET fibre is used namely, 0.5%, 1% and 1.5%. All RC beam specimens are tested under four point loading under flexural capacity behaviour. Prior to structural test, the materials properties which include the compressive and tensile strength test and modulus of elasticity test were determined. The results than are compared with control RC beam. It is found that the RC beam with IPET fibre does not significantly change the behaviour of failure mode, cracking propagation and pattern compared to control RC beam.

Abstract: A coupled thermo-mechanical model is employed to analyze the thermo-mechanical behavior of a widely used laminated composite subject to temperature decrease at service conditions. Three sets of governing equations, i.e. heat transfer, thermo-mechanical deformation and damage evolution are respectively described in the model. These equations are then assembled into a coupled matrix equation using finite element formulation and then solved simultaneously at each time interval. A numerical model of two layered composites with some preexisting equal-spacing cracks along the interface in the lower layer is set up to investigate the thermal induced crack propagation due to temperature decrease. Results are presented in the form of crack propagation process in stress profiles and discussed. Numerical simulations show that the crack propagation behavior of the composites is closely dependent on the physico-mechanical properties of two layers and preexisting cracks. It is found that thermal induced cracks penetrate into the upper layer and grow in the upper layer due to the low strength of the upper layer when the model is subject to uniform temperature decrease.

Abstract: Wear is often of definite influence in the service life of mechanical components and has been recognised as one of the major causes of failure in engineering practice. It is noted that although extensive attention has been paid to phenomenological studies like surface morphology analysis for wear assessment, the physical mechanism of wear particle formation remains unclear. This paper proposes a micro damage and fracture model to simulate the process of wear particle generation. An explicit finite element (FE) formulation is employed to capture the nonlinearities involved. Unlike existing FE analysis (FEA), any initial sub-fractures underlying the wear surface are no longer required. Crack initiation and propagation as well as the corresponding mesh updating are implemented in an automatic fashion associated with the explicit FE framework. The results presented are in good agreement with experimental observation and the reports in existing literature.