Performance evaluation of implicit and explicit method of finite element dynamic analysis using GPGPU

2017 ◽  
Vol 2017.30 (0) ◽  
pp. 134
Author(s):  
Kazuki MATSUMURA ◽  
Fei JIANG ◽  
Xian CHEN ◽  
Junji OHGI
2011 ◽  
Vol 52-54 ◽  
pp. 1698-1702
Author(s):  
Xu Dong Yang ◽  
Liang Liang Jin ◽  
Jia Chun Li ◽  
Zhi Qiang Jin ◽  
Jin Zhao

The finite element model of cross simulator including supporting structure, beam, etc. was set up in the environment of ABAQUS. After the static analysis which meets the requirements, the model’s dynamic characteristics when bearing impact load was obtained using explicit method according to modal analysis results. Comparing different analysis results with technical index, it indicates that larger impact load makes the dynamic characteristics worse significantly.


2018 ◽  
Vol 9 (4) ◽  
pp. 465-474 ◽  
Author(s):  
Evangelos Gavalas ◽  
Ioannis Pressas ◽  
Spyros Papaefthymiou

Purpose The purpose of this paper is to compare the performance of implicit and explicit integration schemes for simulating the metal rolling process using commercial software packages ANSYS™ and LS-DYNA™. Design/methodology/approach For the industrial application of finite element method, the time discretization is one of the most important factors that determine the stability and efficiency of the analysis. An iterative approach, which is unconditionally stable in linear analyses, is the obvious choice for a quasi-static problem such as metal rolling. However, this approach may be challenging in achieving convergence with non-linear material behavior and complicated contact conditions. Therefore, a non-iterative method is usually adopted, in order to achieve computational accuracy through very small time steps. Models using both methods were constructed and compared for computational efficiency. Findings The results indicate that the explicit method yields higher levels of efficiency compared to the implicit method as model complexity increases. Furthermore, the implicit method displayed instabilities and numerical difficulties in certain load conditions further disfavoring the solver’s performance. Originality/value Comparison of the implicit and explicit procedures for time stepping was applied in 3D finite element analysis of the plate rolling process in order to evaluate and quantify the computational efficiency.


Author(s):  
Tsu-te Wu

The explicit method of the finite-element analysis is capable of analyzing the dynamic responses of a complex structure with complicated contact conditions. The method has been widely used in evaluating the dynamic responses of shipping package for radioactive materials. However, the previous analyses focused on the stresses and deformations of the structure components subjected impact loads and the possibility of the locking-ring closure separating from the drum body is not accounted for. The major difficulty for applying the explicit method to a container with a locking-ring closure is that the phenomenon of pre-loading a locking-ring closure is a static process; whereas, the explicit method involves the propagation of stress waves in the structure and thus is only applicable to dynamic analyses. The purpose of the present paper is to propose a technique that extends the application of the explicit finite-element method to the dynamic analysis of the container pre-loaded by a lock-ring. Unlike the conventional dynamic analysis by the explicit method that only needs one load step, the proposed technique requires three sequential procedure steps (not load steps) to complete an entire analysis. Furthermore, one procedure step may consist of two load steps. The paper discusses the procedures of the proposed technique in details. The application of the technique is illustrated by an example problem. The adequacy of the technique is also verified.


Vibration ◽  
2021 ◽  
Vol 4 (1) ◽  
pp. 151-174
Author(s):  
André F. S. Rodrigues ◽  
Zuzana Dimitrovová

In this paper, the three-layer model of ballasted railway track with discrete supports is analyzed to access its applicability. The model is referred as the discrete support model and abbreviated by DSM. For calibration, a 3D finite element (FE) model is created and validated by experiments. Formulas available in the literature are analyzed and new formulas for identifying parameters of the DSM are derived and validated over the range of typical track properties. These formulas are determined by fitting the results of the DSM to the 3D FE model using metaheuristic optimization. In addition, the range of applicability of the DSM is established. The new formulas are presented as a simple computational engineering tool, allowing one to calculate all the data needed for the DSM by adopting the geometrical and basic mechanical properties of the track. It is demonstrated that the currently available formulas have to be adapted to include inertial effects of the dynamically activated part of the foundation and that the contribution of the shear stiffness, being determined by ballast and foundation properties, is essential. Based on this conclusion, all similar models that neglect the shear resistance of the model and inertial properties of the foundation are unable to reproduce the deflection shape of the rail in a general way.


2018 ◽  
Vol 18 (02) ◽  
pp. 1850017 ◽  
Author(s):  
Iwona Adamiec-Wójcik ◽  
Łukasz Drąg ◽  
Stanisław Wojciech

The static and dynamic analysis of slender systems, which in this paper comprise lines and flexible links of manipulators, requires large deformations to be taken into consideration. This paper presents a modification of the rigid finite element method which enables modeling of such systems to include bending, torsional and longitudinal flexibility. In the formulation used, the elements into which the link is divided have seven DOFs. These describe the position of a chosen point, the extension of the element, and its orientation by means of the Euler angles Z[Formula: see text]Y[Formula: see text]X[Formula: see text]. Elements are connected by means of geometrical constraint equations. A compact algorithm for formulating and integrating the equations of motion is given. Models and programs are verified by comparing the results to those obtained by analytical solution and those from the finite element method. Finally, they are used to solve a benchmark problem encountered in nonlinear dynamic analysis of multibody systems.


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