Effect of Crack Severity on a Curved Cantilever Beam Using Differential Quadrature Element Method

Author(s):  
Baharul Islam ◽  
Prases K. Mohanty ◽  
Dayal R. Parhi
2000 ◽  
Author(s):  
Chang-New Chen

Abstract The differential quadrature element method (DQEM) and the extended differential quadrature (EDQ) have been proposed by the author. The EDQ is used to the DQEM vibration analysis frame structures. The element can be a nonprismatic beam considering the warping due to torsion. The EDQ technique is used to discretize the element-based differential eigenvalue equations, the transition conditions at joints and the boundary conditions on domain boundaries. An overall discrete eigenvalue system can be obtained by assembling all of the discretized equations. A numerically rigorous solution can be obtained by solving the overall discrete eigenvalue system. Mathematical formulations for the EDQ-based DQEM vibration analysis of nonprismatic structures considering the effect of warping torsion are carried out. By using this DQEM model, accurate results of frame problems can efficiently be obtained.


1999 ◽  
Vol 121 (2) ◽  
pp. 204-208 ◽  
Author(s):  
F.-L. Liu ◽  
K. M. Liew

A new numerical technique, the differential quadrature element method (DQEM), has been developed for solving the free vibration of the discontinuous Mindlin plate in this paper. By the DQEM, the complex plate domain is decomposed into small simple continuous subdomains (elements) and the differential quadrature method (DQM) is applied to each continuous subdomain to solve the problems. The detailed formulations for the DQEM and the connection conditions between each element are presented. Several numerical examples are analyzed to demonstrate the accuracy and applicability of this new method to the free vibration analysis of the Mindlin plate with various discontinuities which are not solvable directly using the differential quadrature method.


Author(s):  
Laleh Fatahi ◽  
Shapour Moradi

The following study deals with improving the vibration model of structures obtained by the differential quadrature element method. To this end, first, an initial model of the structure is constructed using the differential quadrature element method in which the values of several physical parameters are unknown. Then, an optimization problem is defined to find the optimum values of the design parameters. In fact, the aim is to minimize an objective function that consists of the weighted sum of the squared errors between the modal parameters (i.e. the natural frequencies, the mode shapes, and the damping ratios) of the differential quadrature element and the experimental models. To solve the optimization problem, a robust evolutionary algorithm, namely the artificial bee colony, is utilized. To verify the effectiveness of the presented approach, the experimental data obtained from the modal testing of a plane frame are utilized to update its differential quadrature element model. The results show that the updating process is successfully performed utilizing artificial bee colony, and the updated differential quadrature element model better represents the vibration behavior of the real structure. Besides, the sensitivities of the eigenvalues of the model with respect to the design parameters are also evaluated to demonstrate the effect of changing the design parameters in the modal parameters of the model.


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