Applied Mechanics and Materials Vol. 367

Abstract: In this paper, thehydrothermal synthesis of NaY zeolite, and using SEM, XRD and FT-IR werecharacterized, on the crystallization process parameters were discussed andoptimized. Finalized under 100°Cin a particular formulation 12h synthetic zeolite crystallization has a highercrystallization rate and purity suitable for preparation of zeolite membranesas a seed.

Abstract: The investigation on the sensitivity of the flows to the initial conditions was carried with varying grid resolutions, turbulence models and perturbations. The Direct Numerical Simulation study of Pantano and Sarkar [1] was taken as the reference study and the computational model used in this study was built with a similar configuration of theirs except for the perturbations used. Important results were arrived pertaining to the effect of initial conditions on the turbulent properties and the turbulent structures of the flow.

Abstract: The model of finite element analysis is established reasonably through combining the principle of gear engagement, contact mechanics, and finite element concept and method. Simulation analysis is made for the meshing process of the internal gear pairs with few teeth difference using finite element method. It is found out that the effect of cusp contact along the direction of tooth depth will be generated in the meshing process of the internal gear pairs with few teeth difference when studying the multi-teeth contact. The complexity of multi-teeth meshing effect and the effect of the effect of cusp contact during the meshing process is pointed out.

Abstract: The paper deals with dynamic stability and natural frequency of composite corrugated bellows expansion joint. In this simplified formulae are developed by a thin walled pipe model. The dynamic model determined by integration method. According to the EJMA formulae the torsional stability calculation is modified using two different equivalent radii. The torsional natural frequencies are calculated using the formula based on equivalent thin walled pipe model. The modified formulae are verified by those from a finite element model and good agreement is shown between the simplified formulae and the finite element model.

Abstract: When designing a tire, a good contact pressure distribution and a good contact area are necessary. The contact pressure and contact area are determined by tire material and structure, but there is few public researches on these. So, in this article, tire material properties’ influence on tire/road contact pressure and area are analyzed by using finite element method. The results show that there are ten rubber materials have negative correlation with contact pressure, the most effective material is tread rubber; there are four rebar materials have positive relation with contact pressure, the major is the first belt rebar. But they are different in contact area: the most effective rebar to contact area is bead rebar. The positive and negative effect factors and the effect coefficients are obtained for the seventeen rubber materials and seven rebar materials in tire about contact pressure and contact area. That has an important guidance on tire design and engineering applications.

Abstract: There are formalisms available in the literature for determining the force and torque on a particle moving in a fluid at zero and low Reynolds numbers. The formalism for determining the force and torque on a particle in a fluid at arbitrary Reynolds numbers has only recently been developed, Magnaudet [. This paper focuses on developing a formalism for the special case of a sphere moving in a quiescent fluid at arbitrary Reynolds numbers using the formalism of Magnaudet.

Abstract: Fatigue cracks nucleate at the surface of the shaft operating under cyclic load. These cracks then grow into semi-elliptical shapes while extending into the shaft. The paper presents numerical estimation of stress intensity factor (SIF) of such cracks in circular solid shaft when subjected to bending and twisting loads in elastic conditions. The finite element model is first validated with the help of results reported elsewhere for a single surface crack. Later on, multiple coplanar surface cracks are modeled and the effect of the number of cracks and the distance between them on SIF of the main crack is investigated. The results are in line with the expectations.Nomenclature

Abstract: Tremendous efforts were made in the last couple of decades showing remarkable development in new welding technologies for defect free structures capable of excellent in-service thermal and structural load bearing features. The weld penetration plays an important role in weld induced imperfections and transient temperature distributions followed by transient and residual stress fields. This paper therefore, presents the investigation on the finite element analysis using COMSOL Multiphysics and MATLAB with moving heat sources, temperature dependent material properties, and transient heat transfer and the experimental study by thermogrphy method to the analysis of arc welded plates of Al.alloy 6061-T6 and shows a good co-relation and also close agreement to the previously published literature for temperature distribution. The effect of process parameters viz., welding speed, arc current and standoff distance on weld penetration also has been studied.

Abstract: Full Authority Digital Electronic Control (FADEC) system is common in all modern jet engines. In jet engine, the simplest control system is to produce desired engine thrust by changing the fuel flow. Since in flight engine thrust measurement is practically not possible, engine low pressure shaft rotational speed (N1/NL), engine pressure ratio (EPR), or exhaust jet temperature (EJT) has been effectively used as an indicator of the engine thrust. In this paper, the model used is twin spool turbofan engine. If any fault occurs in N1 sensor, the entire engine operation will be affected. Since there exists a unique aerodynamic relationship among the spool speeds, if any fault occurs in N1 sensor, engine thrust can be controlled with a certain amount of degradation using high pressure spool speed (N2/NH).Both soft and hard failures are detected using kalman filter, range, rate and comparison techniques. The effectiveness of the proposed approach is demonstrated by means of simulations.

Abstract: This paper focuses on optimizing the design of an eco-car chassis cross-section. This is done by constructing design maps and by carrying out a parametric study on the relative stiffness and mass of three different cross-sections: round-tubular, square-tubular and I-section. The objective is to determine the section that yields the desired safety factor while maintaining the lowest possible mass. An iterative approach is employed and the safety of the final design is verified both numerically and experimentally.