scholarly journals COMPARISON OF VIRTUAL FIELDS METHOD, PARALLEL NETWORK MATERIAL MODEL AND FINITE ELEMENT UPDATING FOR MATERIAL PARAMETER DETERMINATION

2016 ◽  
Vol 7 ◽  
pp. 7
Author(s):  
Florian Dirisamer ◽  
Umut D. Çakmak ◽  
Imre Kállai ◽  
Martín Machado ◽  
Zoltán Major

Extracting material parameters from test specimens is very intensive in terms of cost and time, especially for viscoelastic material models, where the parameters are dependent of time (frequency), temperature and environmental conditions. Therefore, three different methods for extracting these parameters were tested. Firstly, digital image correlation combined with virtual fields method, secondly, a parallel network material model and thirdly, finite element updating. These three methods are shown and the results are compared in terms of accuracy and experimental effort.

2019 ◽  
Author(s):  
Rolland Delorme ◽  
Patrick Diehl ◽  
Ilyass Tabiai ◽  
Louis Laberge Lebel ◽  
Martin Levesque

This paper implements the Virtual Fields Method within the ordinary state based peridynamic framework to identify material properties. The key equations derived in this approach are based on the principle of virtual works written under the ordinary state based peridynamic formalism for two-dimensional isotropic linear elasticity. In-house codes including a minimization process have also been developed to implement the method. A three-point bending test and two independent virtual fields arbitrarily chosen are used as a case study throughout the paper. The numerical validation of the virtual fields method has been performed on the case study by simulating the displacement field by finite element analysis. This field has been used to extract the elastic material properties and compared them to those used as input in the finite element model, showing the robustness of the approach. Noise analysis and the effect of the missing displacement fields on the specimen’s edges to simulate digital image correlation limitations have also been studied in the numerical part. This work focuses on pre-damage properties to demonstrate the feasibility of the method and provides a new tool for using full-field measurements within peridynamics with a reduced calculation time as there is no need to compute the displacement field. Future works will deal with damage properties which is the main strength of peridynamics.


2014 ◽  
Vol 611 ◽  
pp. 188-193 ◽  
Author(s):  
Vladimír Ivančo ◽  
Gabriel Fedorko ◽  
Ladislav Novotný

In the paper, the influence of material model selection on the behaviour of Finite Element model of a compressed thin-walled channel is studied. Results of three material models of channels of two different lengths and two types of geometric imperfections are compared and discussed.


2010 ◽  
Vol 165 ◽  
pp. 394-399 ◽  
Author(s):  
E. Szymczyk ◽  
Grzegorz Slawinski

The paper deals with the numerical analysis of a tensile loaded riveted joint. Finite element simulations of the upsetting process were carried out with the use of Marc code to determine the residual stress field. The contact with friction is defined between the mating parts of the joint. The computations were performed for four cases of material and load conditions and a comparison was performed on the basis of results obtained for standard elasto plastic and Gurson material models. Moreover, the influence of material model and residual stress on the tensile loaded joint was analyzed.


Author(s):  
Jennifer M. Bastiaan ◽  
Amir Khajepour

A physical testing program is performed in support of finite element model creation for a 50-series passenger car tire. ABAQUS finite element analysis software is used along with its standard material models. Uniaxial tension testing of tire samples cut from the tread composite, tread rubber and sidewall composite is performed in order to obtain material properties. Hyper-elastic material coefficients for tread rubber are fit using uniaxial tension test data. Results show that the Arruda-Boyce hyper-elastic material model fits the test data well and it predicts reasonable overall behavior in uniaxial tension and uniaxial compression. Most other hyperelastic material models are found to predict unrealistic behavior in uniaxial compression for the tire samples, especially in the 0 to 20% compressive strain range. Frequency response testing of two inflated passenger car tires of different sizes, makes and models is also performed to assist in defining the viscoelastic material model for tread rubber. Test results show that tire modal damping is in the 2 to 4% range for most modes below 200 Hz, and the response curves, modal density and modal damping are remarkably similar for the two tires tested. The tire finite element model with updated material properties is simulated for nine combinations of air inflation pressure and vertical load in order to calculate static loaded radius. The analysis results are compared with physical test results and the analysis results are found to deviate at most by 3% compared to the tests.


1996 ◽  
Vol 118 (4) ◽  
pp. 503-508 ◽  
Author(s):  
G. E. Vallee ◽  
Arun Shukla

A numerical method is described for determining a dynamic finite element material model for elastomeric materials loaded primarily in compression. The method employs data obtained using the Split Hopkinson Pressure Bar (SHPB) technique to define a molecular constitutive model for elastomers. The molecular theory is then used to predict dynamic material behavior in several additional deformation modes used by the ABAQUS/Explicit (Hibbitt, Karlsson, and Sorenson, 1993a) commercial finite element program to define hyperelastic material behavior. The resulting dynamic material models are used to create a finite element model of the SHPB system, yielding insights into both the accuracy of the material models and the SHPB technique itself when used to determine the dynamic behavior of elastomeric materials. Impact loading of larger elastomeric specimens whose size prohibits examination by the SHPB technique are examined and compared to the results of dynamic load-deflection experiments to further verify the dynamic material models.


2021 ◽  
Vol 2021 (1) ◽  
pp. 28-33
Author(s):  
Andrey Kirichek ◽  
Sergey Barinov ◽  
Sergey Silantiev ◽  
Aleksandr Yashin ◽  
Aleksey Zaycev

The problem of necessity in the development of loading environment models (materials processed) which has great importance at the finite element simulation of basic processes (technologies) is considered. As a rule, material model programs embedded into CAE cannot be used completely in the computations because of their limited set of physical-mechanical properties, most often insufficient for the adequate simulation of the process under investigation. By the example of the technology of wave deformation strengthening taking into account its peculiarities in the paper for the first time there are developed material models: steel45, BrAZh9-4; VT1-0; B-95 and the estimation of their adequacy is carried out. The creation of each model of material is a unique process and implies not only the pattern completion with data from reference books, but also with data obtained as a result of the fulfillment of corresponding experimental investigations of properties peculiar to material under working. As a result there are developed adequate models of materials having an admissible error (not exceeding 7.4%) for micro-hardness and depth of surface layer strengthening that allows recommending their use at the investigation of wave deformation strengthening through a finite element method.


2018 ◽  
Vol 53 (5) ◽  
pp. 302-312 ◽  
Author(s):  
Gioacchino Alotta ◽  
Olga Barrera ◽  
Elise C Pegg

Wear debris from ultra-high-molecular-weight polyethylene components used for joint replacement prostheses can cause significant clinical complications, and it is essential to be able to predict implant wear accurately in vitro to prevent unsafe implant designs continuing to clinical trials. The established method to predict wear is simulator testing, but the significant equipment costs, experimental time and equipment availability can be prohibitive. It is possible to predict implant wear using finite element methods, though those reported in the literature simplify the material behaviour of polyethylene and typically use linear or elastoplastic material models. Such models cannot represent the creep or viscoelastic material behaviour and may introduce significant error. However, the magnitude of this error and the importance of this simplification have never been determined. This study compares the volume of predicted wear from a standard elastoplastic model, to a fractional viscoelastic material model. Both models have been fitted to the experimental data. Standard tensile tests in accordance with ISO 527-3 and tensile creep recovery tests were performed to experimentally characterise both (a) the elastoplastic parameters and (b) creep and relaxation behaviour of the ultra-high molecular weight polyethylene. Digital image correlation technique was used in order to measure the strain field. The predicted wear with the two material models was compared for a finite element model of a mobile-bearing unicompartmental knee replacement, and wear predictions were made using Archard’s law. The fractional viscoelastic material model predicted almost ten times as much wear compared to the elastoplastic material representation. This work quantifies, for the first time, the error introduced by use of a simplified material model in polyethylene wear predictions, and shows the importance of representing the viscoelastic behaviour of polyethylene for wear predictions.


2018 ◽  
Vol 10 (6) ◽  
pp. 168781401878002 ◽  
Author(s):  
Wei-chen Lee ◽  
Chen-hao Zhang

The objective of this research was to investigate the effects of material models, element types, and boundary conditions on the consistency of finite element analysis. Two cantilever beams were used; one made of stainless steel SUS301 3/4H and the other made of polymer polyoxymethylene. The load–deflection curves of the two cantilever beams obtained by experiments were compared to those obtained by finite element analysis, where the material models—including bilinear, trilinear, and multi-linear—were used. Four element types—beam, plane stress, shell, and solid—were also employed with the material models to obtain the simulated load–deflection curves of the cantilever beams. It was found that bilinear material models had the stiffest behavior due to their overestimated yield strength. In addition, by applying a finite displacement to simulate the grip of the cantilever beams, the discrepancy between the simulated permanent set and the experimental set could be reduced from 80% to 5%. To sum up, both the selection of the material model and the setup of the boundary conditions are critical for obtaining good agreement between the finite element analysis results and the experimental data.


Author(s):  
Maryam Shirmohammadi ◽  
Prasad KDV Yarlagadda

Abstract Finite element (FE) models of uniaxial loading of pumpkin peel and flesh tissues were developed and validated using experimental results. The tensile model was developed for both linear elastic and plastic material models, the compression model was developed only with the plastic material model. The outcomes of force versus time curves obtained from FE models followed similar pattern to the experimental curves; however the curve resulted with linear elastic material properties had a higher difference with the experimental curves. The values of predicted forces were determined and compared with the experimental curve. An error indicator was introduced and computed for each case and compared. Additionally, Root Mean Square Error (RMSE) values were also calculated for each model and compared. The results of modeling were used to develop material model for peel and flesh tissues in FE modeling of mechanical peeling of tough skin vegetables. The results presented in this paper are a part of a study on mechanical properties of agricultural tissues focusing on mechanical peeling methods using mathematical, experimental and computational modeling.


2020 ◽  
Author(s):  
Danuta Miedzińska

The paper deals with numerical simulations of materials printed with SLA technology. SLA (stereolitography) is an additive manufacturing technique, which main idea is printing with the use of a photocurable resin, e.g. epoxy or acrylic. The crosslinking is carried out under UV exposition. The chosen resin was experimentally tested and then numerical analyses were carried out using material models available in LS Dyna library (MAT_24, MAT_168, MAT_081). The results were compared. The best convergence was achieved for MAT_168.


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