A Nonlinear Elastic Model for Isotropic Materials With Different Behavior in Tension and Compression

1982 ◽  
Vol 104 (1) ◽  
pp. 26-28 ◽  
Author(s):  
Gianluca Medri
Keyword(s):  
Mechanical Characterization ◽  
Three Dimensional ◽  
Small Deformation ◽  
Stress And Strain ◽  
Elastic Model ◽  
Strain Fields ◽  
Isotropic Materials ◽  
Tension And Compression ◽  
Nonlinear Elastic

This note presents a model suitable for the mechanical characterization of isotropic materials with different behavior in tension and compression. The model has been derived from the nonlinear elastic theory and elaborated to adapt it to the small deformation field; the constitutive relation may reliably correlate stress and strain fields even in three-dimensional elastic problems.

scholarly journals Modeling of the Tension and Compression Behavior of Sintered 316L Using Micro Computed Tomography

2015 ◽  
Vol 9 (2) ◽  
pp. 70-74 ◽  
Author(s):  
Michał Doroszko ◽  
Andrzej Seweryn
Keyword(s):  
Numerical Modeling ◽  
Three Dimensional ◽  
Stress And Strain ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Strain Fields ◽  
Compression Behavior ◽  
X Ray ◽  
Tension And Compression ◽  
Material Discontinuities

Abstract This paper describes the method of numerical modeling of the tension and compression behavior of sintered 316L. In order to take into account the shape of the mesostructures of materials in the numerical modeling, X-ray microtomography was used. Based on the micro-CT images, three-dimensional geometrical models mapped shapes of the porosity were generated. To the numerical calculations was used finite element method. Based on the received stress and strain fields was described the mechanism of deformation of the materials until fracture. The influence of material discontinuities at the mesoscopic scale on macromechanical properties of the porous materials was investigated.

Wave motion in relaxation-testing of nonlinear elastic media

2005 ◽  
Vol 461 (2058) ◽  
pp. 1599-1626 ◽  
Author(s):  
Ali Nekouzadeh ◽  
Guy M Genin ◽  
Philip V Bayly ◽  
Elliot L Elson
Keyword(s):  
Wave Motion ◽  
Wave Speed ◽  
Mechanical Characterization ◽  
Wave Pattern ◽  
Elastic Model ◽  
Dynamic Experiments ◽  
Propagation Of Waves ◽  
Nonlinear Elastic ◽  
Wave Properties

Relaxation testing is a fundamental tool for mechanical characterization of viscoelastic materials. Inertial effects are usually neglected when analysing these tests. However, relaxation tests involve sudden stretching of specimens, which causes propagation of waves whose effects may be significant. We study wave motion in a nonlinear elastic model specimen and derive expressions for the conditions under which loading may be considered to be quasi-static. Additionally, we derive expressions for wave properties such as wave speed and the time needed to reach a steady-state wave pattern. These expressions can be used to deduce nonlinear elastic material properties from dynamic experiments.

scholarly journals Analysis of Stress Deformation Characteristics of Composite Geomembrane Rock-Fill Dam with Core Wall

2013 ◽  
Vol 470 ◽  
pp. 962-965
Author(s):  
Dong Yan Ding ◽  
Jian Min Ren
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Elastic Model ◽  
Deformation Characteristics ◽  
Distribution Rule ◽  
Dimensional Finite Element ◽  
Stress And Deformation ◽  
Three Dimensional Finite Element ◽  
Nonlinear Elastic

The Chengzigou hydropower station of composite geomembrane rockfill dam as an example of the dam body and the composite geotechnical membrane stress and deformation characteristics are used nonlinear elastic model - Duncan EB model establish three-dimensional finite element model of rockfill,by using the large finite element softwareFLAC3D,whice provided geogrid element to simulate lexible geomembrane shear interaction with soil.The stress and deformation of the dam and the composite geomembrane is calculated under two conditionscompletion period and impoundment period.And analyze the change of the stress and strain distribution rule,whice will provide the basis for the design of the geomembrane.

Three-Dimensional Nonlinear Finite Element Analysis on the Concrete Face Cock-Fill Dam of TianChi Upper Reservoir

2013 ◽  
Vol 838-841 ◽  
pp. 1763-1767
Author(s):  
Shuang Mei Chang ◽  
Wen She He ◽  
Yu Qiang Cheng ◽  
Su Min Zhao
Keyword(s):  
Finite Element ◽  
Water Pressure ◽  
Three Dimensional ◽  
Elastic Model ◽  
Finite Element Software ◽  
Dimensional Finite Element ◽  
Stress And Deformation ◽  
Three Dimensional Finite Element ◽  
Nonlinear Elastic ◽  
Concrete Face

Taking the concrete face cock-fill dam upper reservoir of Tianchi as an example, the stress and deformation characteristics of concrete face rock-fill dam are studied in-depth in this paper. The article builds a fine three-dimensional finite element model of Tianchi upper reservoir by a nonlinear elastic model of the finite element software ADINA. The stress and deformation of the two conditions under completion and storage for the dam are calculated ,which will be analyzed to obtain stress - strain distribution of the dam in two conditions, comparing dam stress and deformation before and after impoundment to get impact of the water pressure on the dam stress and deformation: comparing after impoundment and completion , the dam water level displacement of upstream side from role of horizontal water pressure will increase , the dam upstream offsets to downstream , but the offset is little ; Due to dam is affected by vertical hydrostatic pressure and uplift pressure after impoundment , the dam settlement is slightly less than the completion in storage. KEY WORDS: Tianchi upper reservoir, The concrete face cock-fill dam, Three-dimensional finite element, Nonlinear elastic model, Analysis of stress and deformation

Three-Dimensional Finite Element Analysis of Subsurface Stress and Strain Fields Due to Sliding Contact on an Elastic-Plastic Layered Medium

1997 ◽  
Vol 119 (2) ◽  
pp. 332-341 ◽  
Author(s):  
E. R. Kral ◽  
K. Komvopoulos
Keyword(s):  
Finite Element Analysis ◽  
Material Properties ◽  
Layered Medium ◽  
Three Dimensional ◽  
Stress And Strain ◽  
Element Analysis ◽  
Strain Fields ◽  
Contact Loads ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

A three-dimensional finite element analysis of a rigid sphere sliding on an elastic-plastic layered medium is presented. Results for the subsurface stress and strain fields are given for a perfectly adhering layer with an elastic modulus and yield stress both two and four times that of the substrate, and contact loads 100 and 200 times the initial yield load of the substrate material. Sliding is simulated to distances of approximately two to three times the initial contact radius. The sphere is modeled by contact elements, and the interface friction coefficient is assumed equal to 0.1 and 0.25. The effects of layer material properties, contact friction, and normal load on the sliding and residual stresses in the layer and the substrate are examined. The distributions of tensile stresses in the layered medium and shear stresses at the layer/substrate interface are presented and their significance for crack initiation and layer decohesion is discussed. Reyielding during unloading is also analyzed for different material properties and contact loads.

scholarly journals Mechanical Characterization of Timber-to-Timber Composite (TTC) Joints with Self-Tapping Screws in a Standard Push-Out Setup

2020 ◽  
Vol 10 (18) ◽  
pp. 6534
Author(s):  
Chiara Bedon ◽  
Martina Sciomenta ◽  
Massimo Fragiacomo
Keyword(s):  
Mechanical Characterization ◽  
Numerical Models ◽  
Three Dimensional ◽  
Analytical Models ◽  
Small Scale ◽  
Load Bearing ◽  
Timber Constructions ◽  
Technical Interest ◽  
Push Out

Self-tapping screws (STSs) can be efficiently used in various fastening solutions for timber constructions and are notoriously able to offer high stiffness and load-carrying capacity, compared to other timber-to-timber composite (TTC) joint typologies. The geometrical and mechanical characterization of TTC joints, however, is often hard and uncertain, due to a combination of various influencing parameters and mechanical aspects. Among others, the effects of friction phenomena between the system components and their reciprocal interaction under the imposed design loads can remarkably influence the final estimates on structural capacity, in the same way of possible variations in the boundary conditions. The use of Finite Element (FE) numerical models is well-known to represent a robust tool and a valid alternative to costly and time consuming experiments and allows one to further explore the selected load-bearing components at a more refined level. Based on previous research efforts, this paper presents an extended FE investigation based on full three-dimensional (3D) brick models and surface-based cohesive zone modelling (CZM) techniques. The attention is focused on the mechanical characterization of small-scale TTC specimens with inclined STSs having variable configurations, under a standard push-out (PO) setup. Based on experimental data and analytical models of literature, an extended parametric investigation is presented and correlation formulae are proposed for the analysis of maximum resistance and stiffness variations. The attention is then focused on the load-bearing role of the steel screws, as an active component of TTC joints, based on the analysis of sustained resultant force contributions. The sensitivity of PO numerical estimates to few key input parameters of technical interest, including boundaries, friction and basic damage parameters, is thus discussed in the paper.

Fast Fourier Transform Based Numerical Methods for Elasto-Plastic Contacts of Nominally Flat Surfaces

2008 ◽  
Vol 75 (1) ◽  
Author(s):  
W. Wayne Chen ◽  
Shuangbiao Liu ◽  
Q. Jane Wang
Keyword(s):  
Fourier Transform ◽  
Numerical Methods ◽  
Fast Fourier Transform ◽  
Analytical Solutions ◽  
Three Dimensional ◽  
Stress And Strain ◽  
Two Dimensional ◽  
Response Functions ◽  
Strain Fields ◽  
Flat Surfaces

This paper presents a three-dimensional numerical elasto-plastic model for the contact of nominally flat surfaces based on the periodic expandability of surface topography. This model is built on two algorithms: the continuous convolution and Fourier transform (CC-FT) and discrete convolution and fast Fourier transform (DC-FFT), modified with duplicated padding. This model considers the effect of asperity interactions and gives a detailed description of subsurface stress and strain fields caused by the contact of elasto-plastic solids with rough surfaces. Formulas of the frequency response functions (FRF) for elastic/plastic stresses and residual displacement are given in this paper. The model is verified by comparing the numerical results to several analytical solutions. The model is utilized to simulate the contacts involving a two-dimensional wavy surface and an engineering rough surface in order to examine its capability of evaluating the elasto-plastic contact behaviors of nominally flat surfaces.

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