Papers by Keyword: DQM

Abstract: In this study, the entropy generation due to the flow of a gravity-driven laminar viscous incompressible fluid through an incline channel is investigated. Fully developed flow field is solved for a Newtonian fluid. Then, the temperature field is numerically resolved using Differential Quadrature Method (DQM) subject to isothermal boundary conditions on the walls and constant rectangular profile at the inlet. The result of DQM is compared to analytical solution and method of lines (MOL) numerical method. Rate of entropy generation is found and its relation with temperature and velocity field is examined.

Abstract: Considering the geometric and material coupling of a composite wing, the equations of motion are derived based on Hamilton theory. Frequencies computing and validation of a composite wing with bending-torsion coupling using differential quadrature method (DQM). And the DQM is applied to the flutter speed solution of a composite wing. The results thus obtained are then compared with some available results and a good agreement is observed. The computing time of DQM is highly improved compared with Galerkin method. Moreover, the effect of material coupling rigidity on flutter speed is analyzed and this is important to the design of composite wings.

Abstract: On the basis of fluid-structure-interaction of the liquefaction soil, pipeline and the conveying fluid, in this paper, the differential vibration equations of the buried pipeline are deduced. The differential quadrature method (DQM) was tried to use to analyze the natural frequency of buried pipeline in liquefaction soil under the effect of flow velocity, fluid density, pressure in pipe, viscosity of pipe, axial force, elastic coefficient of the soil. Some preliminary conclusions concerning with the natural frequency of buried pipeline are also obtained. The theoretical research of the seismic effect on the pipeline in the liquefaction soil is presented.

Abstract: In this study, the natural frequencies of composite wings are investigated using the differential quadrature method (DQM) with Mechanical Properties. DQM is an efficient discretization technique for obtaining accurate numerical solutions to initial and/or boundary value problems using a considerably small number of grid points. In this way, a theoretical DQM model for the laminated composite beam has been developed. Some of the results obtained from DQM are compared with the results obtained in the literature. It has been seen that all of the results considered are very close to each other. It is also been concluded that the bending-torsional coupling rigidity of the composite beam has great and different influence on the first three natural frequencies.

Abstract: In this paper, we combined the Fourier cosine series and differential quadrature method (DQM) in barycentric form to develop a new method (FCDQM), which is applied to the 1D fourth order beam problem and the 2D thin isotropic plate problems. Furthermore, we solved the complex boundary conditions on irregular domains with DQM directly. The numerical results illustrate the stability, validity and good accuracy of the method in treating this class of engineering problems.

Abstract: The scale effects on free vibration of micro-plate under the different boundary conditions are studied in this paper. The vibrating differential equation is presented based on modified Cosserat theory and Hamilton principle .The numerical solution is obtained using differential quadrature method. The results show that scale effects is highly significant on the natural frequency when characteristic length and thickness are close, and the natural frequencies increase along with the increase of characteristic length. Additionally, the thickness has significant influence on scale effects and the aspect ratio doesn’t affect.

Abstract: This paper presents a damage detection of surface crack in composite laminate. Carbon/epoxy composite AS4/PEEK was used to fabricate a quasi-isotropic laminate [0/90/±45]2s. Surface crack was created by using laser cutting machine. Modal analysis was performed to obtain the mode shapes of the laminate before and after damage. The mode shapes were then adopted to compute the strain energy, which was used to define a damage index. Consequently, the damage index successfully predicted the location of surface crack in the laminate. Differential quadrature method (DQM) was introduced to calculate the partial differential terms in strain energy formula.