H. El Bhilat; K. El Had; H. Salmi; A. Hachim
Abstract
In this study, the effect of six successive recycling cycles of the recycled material including high impact polystyrene disposable cups on tensile properties, glass transition temperature, flexural, impact strength tests and fluidity were studied. It has been found that after increasing recycling, the ...
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In this study, the effect of six successive recycling cycles of the recycled material including high impact polystyrene disposable cups on tensile properties, glass transition temperature, flexural, impact strength tests and fluidity were studied. It has been found that after increasing recycling, the molar mass and the viscosity decrease (a slight increase of melt flow index) until the fifth cycle; the maximum yielding stress decreased due to material brittleness.The impact strength has only been relatively influenced by a 17% increase, whereas the elongation at break and the Young’s modulus dropped with reprocessing cycles. Glass transition temperature has undergone a remarkable decrease: It dropped in a consistent way by the sixth cycle we measured a drop of almost 11°C was compared to the virgin material, with a notable increase in flexural modulus and hardness. The resulted curves show the reliability of this material to be used after a specific number of processing in several industrial applications.
Fracture Mechanics
H. Salmi; A. Hachim; H. El Bhilat; K. El had
Abstract
The present work deals with the effect of an external circumferential elliptical crack located at thickness transition on a varied stepped diameter pipe .The purpose is the application of the extended finite element method (XFEM) for the calculation of SIF at the thickness transition region of pipe considering ...
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The present work deals with the effect of an external circumferential elliptical crack located at thickness transition on a varied stepped diameter pipe .The purpose is the application of the extended finite element method (XFEM) for the calculation of SIF at the thickness transition region of pipe considering internal pressure and compare the effect of the crack between pipes straight and with thickness transition. To model a crack with precision , enrichment functions are used to enrich the displacement approximation, the level set functions are calculated from the crack mesh and definition of the strategy of integration has been performed.A comparative study is made on SIF of crack defect in straight pipe compared to one with thickness transition using XFEM for the crack and pipe geometrical parameters variations. The result shows that the XFEM is an effective and practical tool for elliptic crack modeling in a pipe with thickness transition because a crack is easily modeled through enrichment functions.The comparison of the SIF of a similar defect between pipes shows that a pressurized pipe with thickness transition is more sensitive to the used cracks.
