Numerical methods solving finite element dynamic equations

2017 ◽  
Vol 54 (2) ◽  
pp. 195-202
Author(s):  
Vasile Nastasescu ◽  
Silvia Marzavan

The paper presents some theoretical and practical issues, particularly useful to users of numerical methods, especially finite element method for the behaviour modelling of the foam materials. Given the characteristics of specific behaviour of the foam materials, the requirement which has to be taken into consideration is the compression, inclusive impact with bodies more rigid then a foam material, when this is used alone or in combination with other materials in the form of composite laminated with various boundary conditions. The results and conclusions presented in this paper are the results of our investigations in the field and relates to the use of LS-Dyna program, but many observations, findings and conclusions, have a general character, valid for use of any numerical analysis by FEM programs.


Author(s):  
Soroosh Hassanpour ◽  
G. R. Heppler

This paper is devoted to the dynamic modeling of micropolar gyroelastic beams and explores some of the modeling and analysis issues related to them. The simplified micropolar beam torsion and bending theories are used to derive the governing dynamic equations of micropolar gyroelastic beams from Hamilton’s principle. Then these equations are solved numerically by utilizing the finite element method and are used to study the spectral and modal behaviour of micropolar gyroelastic beams.


Symmetry ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1489
Author(s):  
Yongbo Guo ◽  
Fansheng Wang

Based on the rigid finite element method and multibody dynamics, a discrete model of a flexible conveyor belt considering the material viscoelasticity is established. RFE (rigid finite element) and SDE (spring damping element) are used to describe the rigidity and flexibility of a conveyor belt. The dynamic differential equations of the RFE are derived by using Lagrange’s equation of the second kind of the non-conservative system. The generalized elastic potential capacity and generalized dissipation force of the SDE are considered. The forward recursive formula is used to construct the conveyor belt model. The validity of dynamic equations of conveyor belt is verified by field test. The starting mode of the conveyor is simulated by the model.


Author(s):  
Vladimir Ivanovich Matselya ◽  
Igor Nikolaevich Seelev ◽  
Alexey Valentinovich Lekontsev ◽  
Robert Rafaelevich Khafizov ◽  
Pavel Viktorovich Yakovlev ◽  
...  

The popularity of numerical methods for modeling soil bases determines the increased demand for the accuracy of calculations. The choice of a model that meets the requirements of accuracy of calculations and minimization of costs is determined by comparative analysis of common soil models described in scientific literature and used in calculations of sediments and dynamic effects of buildings (finite element linear elastic, elastic, ideal-plastic, Mora - Coulomb with strengthening, elasto-plastic with strengthening at small deformation). The results have been obtained on test models using finite element method in the environment of PLAXIS 3D and SCAD Office programs. In order to compare results obtained, subject to requirements of the current regulatory documents, a comparative analysis of soils was carried out according to the model of Body of rules 22.13330.2011 "Foundations of buildings and structures". The analysis results were used for choosing an optimal model of soil bases of industrial buildings estimated in earthquake-proof design. It should be noted that the strong and weak points identified for each model justify the choice of the best model for each particular case.


2018 ◽  
Vol 8 (2) ◽  
pp. 29-34
Author(s):  
A. Moghaddam ◽  
A. Nayeri ◽  
S.M. Mirhosseini

Abstract Although various analytical and numerical methods have been proposed by researchers to solve equations, but use of numerical tools with low volume calculations and high accuracy instead of other numerical methods with high volume calculations is inevitable in the analysis of engineering equations. In this paper, B-Spline spectral method was used to study buckling equations of the piles. Results were compared with the calculated amounts of the exact solution and finite element method. Uniform horizontal reaction coefficient has been used in most of proposed methods for analyzing buckling of the pile on elastic base. In reality, soil horizontal reaction coefficient is nonlinear along the pile. So, in this research by using B-Spline method, buckling equation of the pile with nonlinear horizontal reaction coefficient of the soil was investigated. It is worth mentioning that B-Spline method had not been used for buckling of the pile.


Author(s):  
S. Nakamura ◽  
Rainald Löhner ◽  
Evangelos Hytopoulos ◽  
Tayfun E. Tezduyar ◽  
Marek Behr ◽  
...  

2019 ◽  
Vol 945 ◽  
pp. 857-865
Author(s):  
A.L. Grigorieva ◽  
Y.Y. Grigoriev ◽  
A.I. Khromov

In this paper, we obtained analytical solutions of the fields of strain tensors under uniaxial tension of a rigidplasticstrip underthe conditions of a plane stress state.The topicalityof the construction of these solutions is connected with significant difficulties in determining the strain fields by numerical methods (for example, the finite element method).In the construction of these solutions, the change in the geometric characteristics of the strip (thickness, width) was taken into account, which led to the solution of the nonlinear problem of the continuum mechanics.


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