scholarly journals COMPARATIVE ANALYSIS OF THE PARAMETERS OF FINITE-ELEMENT MODELS OF SOILS OBTAINED BY NUMERICAL METHODS

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.

1999 ◽  
Vol 123 (1) ◽  
pp. 33-42 ◽  
Author(s):  
A. Saxena ◽  
G. K. Ananthasuresh

Optimal design methods that use continuum mechanics models are capable of generating suitable topology, shape, and dimensions of compliant mechanisms for desired specifications. Synthesis procedures that use linear elastic finite element models are not quantitatively accurate for large displacement situations. Also, design specifications involving nonlinear force-deflection characteristics and generation of a curved path for the output port cannot be realized with linear models. In this paper, the synthesis of compliant mechanisms is performed using geometrically nonlinear finite element models that appropriately account for large displacements. Frame elements are chosen because of ease of implementation of the general approach and their ability to capture bending deformations. A method for nonlinear design sensitivity analysis is described. Examples are included to illustrate the usefulness of the synthesis method.


2020 ◽  
Author(s):  
Yaobao Yin ◽  
Chengpeng He ◽  
Jing Li

Abstract The armature assembly of the jet pipe pressure servo valve plays an important role in connecting the torque motor and the jet pipe amplifier. A stiffness model of its complex structure is very necessary for analyzing the dynamic/static performance of the jet pipe pressure servo valve. At the present work, the component parts in the armature assembly are simplified into linear elastic beams. The simplified armature assembly is a fourfold statically indeterminate structure under the premise of small deformation. The unknown forces and moments are solved by using the section continuity condition as the additional supplement equation, and the functional relationship between the electromagnetic torque produced from the torque motor and the armature rotation angle /the nozzle displacement is derived based on the Castigliano's Theorem. The finite element model of the armature assembly is also established to calculate the deformation under different loads and different spring tube lengths. The simulated displacements with the finite element method are consistent with the theoretical results. The experimental results of the recovery pressure of the jet pipe valve verified the theoretical model. The proposed stiffness calculation method can be used as a reference for designing and optimizing the armature assembly in the jet pipe pressure servo valve.


Author(s):  
R. Michael Van Auken

Math models of flexible dynamic systems have been the subject of research and development for many years. One area of interest is exact Laplace domain solutions to the differential equations that describe the linear elastic deformation of idealized structures. These solutions can be compared to and complement finite order models such as state-space and finite element models. Halevi (2005) presented a Laplace domain solution for a finite length rod in torsion governed by a second order wave equation. Using similar methods Van Auken (2010, 2012) presented a Laplace domain solution for the transverse bending of an undamped uniform slender beam based on the fourth order Euler-Bernoulli equation, where it was assumed that rotary inertia and shear effects were negligible. This paper presents a new exact Laplace domain solution to the Timoshenko model for an undamped uniform non-slender beam that accounts for rotary inertia and shear effects. Example models based on the exact Laplace domain solution are compared to finite element models and to slender beam models in order to illustrate the agreement and differences between the methods and models. The method is then applied to an example model a half-car with a flexible body.


2020 ◽  
Vol 23 (2) ◽  
pp. 255-268
Author(s):  
Olga Liivapuu ◽  
Jüri Olt ◽  
Tanel Tärgla

In the process of cutting, often the selection of cutting parameters is done considering empirical methods. This approach is more expensive and does not usually lead to the best solutions. Numerical methods for simulating the chip formation have been under development over the last thirty years. The aim of the present research is to compare models based on rheological properties of metals with 2D Finite Element Models of chip formation process.


2012 ◽  
Vol 450-451 ◽  
pp. 1625-1628
Author(s):  
Li Qin ◽  
Yuan Miao ◽  
Ya Nan Luo

This paper presents a new-type forging flange used in steel transmission towers, that is to forge a same flange and same bolts in large a forging flange, in order to increase the strength and rigidity. This paper seted up finite element models of inner forging flange and outer forging flange. At the same time the article established finite element models of the new-type forging flange and new-type rigid flange used in engineering.The comparative analysis of the results shows that, the new-type forging flanges greatly improved the strength and rigidity of the joints because of the reasonable stress distribution and constraints of deformation.


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