scholarly journals 3D Mesoscale Finite Element Modelling of Concrete under Uniaxial Loadings

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4585
Author(s):  
Tiago Forti ◽  
Gustavo Batistela ◽  
Nadia Forti ◽  
Nicolas Vianna

Concrete exhibits a complex mechanical behavior, especially when approaching failure. Its behavior is governed by the interaction of the heterogeneous structures of the material at the first level of observation below the homogeneous continuum, i.e., at the mesoscale. Concrete is assumed to be a three-phase composite of coarse aggregates, mortar, and the interfacial transitional zone (ITZ) between them. Finite element modeling on a mesoscale requires appropriate meshes that discretize the three concrete components. As the weakest link in concrete, ITZ plays an important role. However, meshing ITZ is a challenging issue, due to its very reduced thickness. Representing ITZ with solid elements of such reduced size would produce very expensive finite element meshes. An alternative is to represent ITZ as zero-thickness interface elements. This work adopts interface elements for ITZ. Damage plasticity model is adopted to describe the softening behavior of mortar in compression, while cohesive fractures describe the cracking process. Numerical experiments are presented. First example deals with the estimation of concrete Young’s modulus. Experimental tests were performed to support the numerical test. A second experiment simulates a uniaxial compression test and last experiment simulates a uniaxial tensile test, where results are compared to data from the literature.

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7665
Author(s):  
Marcin Daniel Gajewski ◽  
Mikołaj Miecznikowski

The paper presents modeling of bridge elastomeric bearings using large deformation theory and hyperelastic constitutive relations. In this work, the simplest neo-Hookean model was compared with the Yeoh model. The parameters of the models were determined from the elastomer uniaxial tensile test and then verified with the results from experimental bearing compression tests. For verification, bearing compression tests were modeled and executed using the finite element method (FEM) in ABAQUS software. Additionally, the parameters of the constitutive models were determined using the inverse analysis method, for which the simulation results were as close as possible to those recorded during the experimental tests. The overall assessment of the suitability of elastomer bearings modeling with neo-Hookean and Yeoh hyperelasticity models is presented in detail.


2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Debora Francisco Lalo ◽  
Marcelo Greco ◽  
Matias Meroniuc

Elastomeric components are widely used in the engineering field since their mechanical properties can vary according to a specific condition, enabling their applications under large deformations and multiaxial loading. In this context, the present study seeks to investigate the main challenges involved in the finite element hyperelasticity simulation of rubber-like material components under different cases of multiaxial loading and precompression. The complex geometry of a conical rubber spring was chosen to deal with several deformation modes; this component is in the suspension system placed between the frame and the axle for railway vehicles. The framework of this study provides the correlation between axial and radial stiffness under precompression obtained by experimental tests in prototypes and virtual modeling obtained through a curve fitting procedure. Since the material approaches incompressibility, different shape functions were adopted to describe the fields of pressure and displacements according to the finite element hybrid formulation. The material parameters were accurately adjusted through an optimization algorithm implemented in Python program language which calibrates the finite element model according to the prototype test data. However, as an initial guess, the proper constitutive model and its parameters were first defined based only on the uniaxial tensile test data, since this test is easy to perform and well understood. The validation of the simulation results in comparison with the experimental data demonstrated that care should be given when the same component is subjected to different multiaxial loading cases.


2019 ◽  
Vol 276 ◽  
pp. 01013
Author(s):  
Ahmad Basshofi Habieb ◽  
Tavio Tavio ◽  
Gabriele Milani ◽  
Usman Wijaya

Lead Rubber Bearing (LRB) has been widely applied for seismic protection of mid and high-rise buildings around the world. Its excellent energy dissipation becomes the most important aspect of this isolation system thanks to the plasticity and recovery behavior of the lead core. Aiming to develop a deeper knowledge on the behavior of LRB’s, a 3D detailed finite element (FE) modeling is performed in Abaqus FE software. Some important parameters involved in the model are plasticity of the lead core and hyper-elasticity and viscosity of the rubber material. The parameters for rubber material are derived from the results of experimental works in the laboratory, including uniaxial tensile test and relaxation test. The bearing model is then subjected to a cyclic shear-test under constant vertical load. The result of the 3D-FE model is then compared with the analytic-Abaqus model for LRB isolators, developed in the literature. Finally, both 3D-FE model and analytic model result in a good agreement on the shear behaviour of the presented LRB.


Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2929
Author(s):  
Andrzej Kubit ◽  
Tomasz Trzepieciński ◽  
Bogdan Krasowski ◽  
Ján Slota ◽  
Emil Spišák

This paper presents a new product, a glass laminate aluminium-reinforced epoxy (GLARE)-based thin-walled structure with a stiffener in the form of a longitudinal rib. The stiffening rib in an outer metallic layer of a GLARE-based panel was fabricated by the incremental sheet forming technique and Alclad 2024-T3 aluminium alloy sheets were used as adherends. The strength properties of the adhesive joint between the layers of the fibre metal laminates (FMLs) were determined in a uniaxial tensile test, peel drum test, tensile/shear test and short-beam three-point-bending test. Two variants of FMLs were considered, with an adhesive film and without an adhesive film between the adherends and the epoxy/glass prepreg. The FMLs were tested at three different temperatures that corresponded to those found under real aircraft operating conditions, i.e., −60 °C, room temperature and +80 °C. It was found that the temperatures do not affect the tensile strength and shear strength of the FMLs tested. However, there was a noticeable increase in the stiffness of samples stretched at reduced temperature. An additional adhesive film layer between the adherends and the glass/epoxy prepreg significantly improves the static peeling strength of the joint both at reduced and at elevated temperatures. A clear increase in the critical force at which buckling occurs has been clearly demonstrated in the uniaxial compression test of GLARE-based rib-stiffened panels. In the case of GLARE-based rib-stiffened panels, the critical force averaged 15,370 N, while for the non-embossed variant, it was 11,430 N, which translates into a 34.5% increase in critical force.


2010 ◽  
Vol 02 (03n04) ◽  
pp. 235-255 ◽  
Author(s):  
MAKOTO UCHIDA ◽  
NAOYA TADA

The two-scale elasto-viscoplastic deformation behavior of amorphous polymer was investigated using the large deformation finite element homogenization method. In order to enable a large time increment for the simulation step in the plastic deformation stage, the tangent modulus method is introduced into the nonaffine molecular chain network theory, which is used to represent the deformation behavior of pure amorphous polymer. Two kinds of heterogeneous microstructures were prepared in this investigation. One was the void model, which contains uniformly or randomly distributed voids, and the other was the heterogeneous strength (HS) model, which contains a distribution of initial shear strength. In the macroscopic scale, initiation and propagation processes of necking during uniaxial tension were considered. The macroscopic nominal stress–strain relation was strongly characterized by the volume fraction and distribution of voids for the void model and by the width of the strength distribution for the HS model. Non-uniform deformation behaviors in microscopic and macroscopic scales are closely related to each other for amorphous polymers because continuous stretching and hardening in the localized zone of the microstructure brings about an increase in macroscopic deformation resistance. Furthermore, computational results obtained from the homogenization model are compared to those obtained from the full-scale finite element model, and the effect of the scale difference between microscopic and macroscopic fields is discussed.


2011 ◽  
Vol 704-705 ◽  
pp. 811-816
Author(s):  
Jian Bin Sang ◽  
Wen Ying Yu ◽  
Bo Liu ◽  
Xiao Lei Li ◽  
Tie Feng Liu

This paper start with a discussion on various types of strain energy functions of rubber like materials. Theoretical analysis based on the strain energy function given in by Y.C.Gao in 1997 is proposed. The material parameters of strain energy function were curve-fitted from the uniaxial tensile test. The selected constitutive relation of rubber like materials was implemented into a finite element code MSC.Marc as a user material subroutine to analyze the thermal and mechanical behavior of rubber seal under the plane strain conditions. Contact force and distribution of the contact stress between lip seal and shaft are analyzed and coupled thermal mechanical analysis of rubber seal was proposed. The contact pressure distribution is readily obtainable from the nonlinear finite element analysis and the coupled thermal mechanical analyses results indicate that the thermal stress only have minor influence on the deformed shape of rubber seal, which will be a useful technique for predicting the properties of rubber seal and providing reference for engineering design. Keywords:rubber like materials, nonlinear finite element, contact analysis, thermal mechanical analysis


Author(s):  
Xiao-Yan Gong ◽  
Alan R. Pelton

Nitinol, an alloy of about 50% Ni and 50% Ti, is a very unique material. At constant temperature above its Austenite finish (Af) temperature, under uniaxial tensile test, the material is highly nonlinear and capable of large deformation to the ultimate strain on the order of 15%. This material behavior, known as superelasticity, along with its excellent biocompatibility and corrosion resistance, makes Nitinol a perfect material candidate for many medical device applications. However, the nonlinear material response also requires a specific material description to perform the stress analysis. The user developed material subroutine from HKS/West makes the simulation of the Nitinol devices possible. This article presents two case studies of the nonlinear finite element analysis using ABAQUS/Standard and the Nitinol UMAT.


Author(s):  
Vishnu Verma ◽  
A. K. Ghosh ◽  
G. Behera ◽  
Kamal Sharma ◽  
R. K. Singh

Miniature disk bending test is used to evaluate the mechanical behavior of irradiated materials and its properties — mainly ductility loss due to irradiation in steel. In Miniature Disk Bending Machine the specimen is firmly held between the two horizontal jaws of punch, and an indentor with spherical ball travels vertically. Researchers have observed reasonable correlations between values of the yield stress, strain hardening and ultimate tensile strength estimated from this test and mechanical properties determined from the uniaxial tensile test. Some methods for the analysis of miniature disk bending, proposed by various authors have been discussed in the paper. It is difficult to distinguish between the regimes of elastic and plastic deformation since local plastic deformation occurs for very small values of load when the magnitude of spatially averaged stress will be well below the yield stress. Also, the analytical solution for large amplitude, plastic deformation becomes rather unwieldy. Hence a finite element analysis has been carried out. The finite element model, considers contact between the indentor and test specimen, friction between various pairs of surfaces and elastic plastic behavior. The load is increased in steps and converged solution has been obtained and analysis terminated at a load beyond which a stable solution cannot be obtained. A sensitivity study has been carried out by varying the various parameters defining the material properties by ±10% around the base values. This study has been carried out to generate a data base for the load-deflection characteristics of similar materials from which the material properties can be evaluated by an inverse calculation. It is seen that the deflection obtained by analytical elastic bending theory is significantly lower than that obtained by the elasto-plastic finite element solution at relatively small values of load. The FE solution and experimental results are in reasonably good agreement.


2014 ◽  
Vol 644-650 ◽  
pp. 670-673
Author(s):  
Guo You Han ◽  
Ming Qi Wang ◽  
Yu Hou ◽  
Qiang Li

The finite element analysis of PCP involves three nonlinear of geometry, material and contact, and the load of PCP is diversity, leading to it difficult to establish the finite element model and calculate by finite method. This article takes GLB120-27 as an example, to establish 3D solid model of PCP by using SolidWorks; to determine M-R model constant of stator rubber by using the data of uniaxial tensile test: to separate the seal band from the stator chamber by using Boolean operation and set up contact pairs, to achieve the correct simulation of stator chamber fluid pressure; to correctly simulate the interference fit between stator and rotor through setting correlation parameters; to establish 3D finite element analysis model and verify the correctness by using the experiment data of hydraulic characteristics of PCP.


Sign in / Sign up

Export Citation Format

Share Document