Characterization of the strain-induced plastic anisotropy of rolled sheets by using sequences of simple shear and uniaxial tensile tests

2006 ◽  
Vol 174 (1-3) ◽  
pp. 115-126 ◽  
Author(s):  
S. Bouvier ◽  
B. Gardey ◽  
H. Haddadi ◽  
C. Teodosiu
Keyword(s):  
Simple Shear ◽  
Plastic Anisotropy ◽  
Tensile Tests ◽  
Uniaxial Tensile

Development of a Global Indicator to Assess Mechanical Tests

2015 ◽  
Vol 651-653 ◽  
pp. 883-888
Author(s):  
Nelson Souto ◽  
Sandrine Thuillier ◽  
António Andrade-Campos
Keyword(s):  
Plane Strain ◽  
Simple Shear ◽  
Kinematic Hardening ◽  
Tensile Tests ◽  
Mechanical Tests ◽  
Material Behavior ◽  
Uniaxial Tensile ◽  
Strain Fields ◽  
Global Indicator

Full-field measurement methods have emerged in the last years and these methods are characterized by directly providing displacement and strain fields for all points over the specimen surface. Thus, the design of heterogeneous tests can be performed for material parameter identification purposes since the inhomogeneous strain fields can be measured. However, (i) no defined criterion yet exists for designing new heterogeneous tests, (ii) it is rather difficult to compare and rate different tests and (iii) a quantitative way to define the best test for material behavior characterization of sheet metals has yet to be proposed. Due to this, the goal of this work is the development of a global indicator able to assess mechanical tests. The proposed indicator quantifies the strain state range, the deformation heterogeneity and the strain level achieved in the test, based on a continuous evaluation of the strain field up to rupture. This global indicator was applied to rank some classical tests, such as uniaxial tensile, simple shear, plane strain and biaxial tensile tests. These tests were carried out numerically by reproducing the virtual behavior of DC04 mild steel. A constitutive model composed by the non-quadratic Yld2004-18p yield criterion combined with a mixed isotropic-kinematic hardening law and a macroscopic rupture criterion was used. The performance of the tests was compared with the indicator and a ranking was established. The results obtained show that biaxial tension is the test providing more information for the mechanical behavior characterization of the material. It was also verified that plane strain test presents a better performance than simple shear and uniaxial tensile tests.

Inverse Mechanical Characterization of Tissue Engineered Heart Valves

2008 ◽  
Author(s):  
Martijn A. J. Cox ◽  
Jeroen Kortsmit ◽  
Niels J. B. Driessen ◽  
Carlijn V. C. Bouten ◽  
Frank P. T. Baaijens
Keyword(s):  
Heart Valves ◽  
Soft Tissues ◽  
Mechanical Characterization ◽  
Tensile Tests ◽  
Material Behavior ◽  
Uniaxial Tensile ◽  
Mechanical Conditioning ◽  
Indentation Tests ◽  
Tissue Engineered Heart Valves

Over the last few years, research interest in tissue engineering as an alternative for current treatment and replacement strategies for cardiovascular and heart valve diseases has significantly increased. In vitro mechanical conditioning is an essential tool for engineering strong implantable tissues [1]. Detailed knowledge of the mechanical properties of the native tissue as well as the properties of the developing engineered constructs is vital for a better understanding and control of the mechanical conditioning process. The nonlinear and anisotropic behavior of soft tissues puts high demands on their mechanical characterization. Current standards in mechanical testing of soft tissues include (multiaxial) tensile testing and indentation tests. Uniaxial tensile tests do not provide sufficient information for characterizing the full anisotropic material behavior, while biaxial tensile tests are difficult to perform, and boundary effects limit the test region to a small central portion of the tissue. In addition, characterization of the local tissue properties from a tensile test is non-trivial. Indentation tests may be used to overcome some of these limitations. Indentation tests are easy to perform and when indenter size is small relative to the tissue dimensions, local characterization is possible. We have demonstrated that by recording deformation gradients and indentation force during a spherical indentation test the anisotropic mechanical behavior of engineered cardiovascular constructs can be characterized [2]. In the current study this combined numerical-experimental approach is used on Tissue Engineered Heart Valves (TEHV).

Methods for the Experimental Evaluation of True Stress-Strain Curves After Necking of Conventional Tensile Specimens: Exploratory Investigation and Proposals

2012 ◽  
Author(s):  
Grace Kelly Q. Ganharul ◽  
Nick de Brangança Azevedo ◽  
Gustavo Henrique B. Donato
Keyword(s):  
Real Time ◽  
Weighted Average ◽  
Tensile Tests ◽  
Plastic Instability ◽  
True Stress ◽  
Experimental Results ◽  
Uniaxial Tensile ◽  
High Definition ◽  
Stress Strain

Numerical elastic-plastic simulations have undergone significant expansion during the last decades (e.g. refined fracture mechanics finite element models including ductile tearing). However, one limitation to increase the accuracy of such models is the reliable experimental characterization of true stress-strain curves from conventional uniaxial tensile tests after necking (plastic instability), which complicates the direct assessment of the true stress-strain curves until failure. As a step in this direction, this work presents four key activities: i) first, existing correction methods are presented, including Bridgman, power law, weighted average and others; ii) second, selected metals are tested to experimentally characterize loads and the geometric evolution of necking. High-definition images are used to obtain real-time measurements following a proposed methodology; iii) third, refined non-linear FEM models are developed to reproduce necking and assess stresses as a function of normalized neck geometry; iv) finally, existing correction methods are critically compared to experimental results and FEM predictions in terms of potential and accuracy. The experimental results evaluated using high-definition images presented an excellent geometrical characterization of instability. FEM models were able to describe stress-strain-displacement fields after necking, supporting the exploratory validations and proposals of this work. Classical methodologies could be adapted based on experiments to provide accurate stress-strain curves up to failure with less need for real-time measurements, thus giving further support to the determination of true material properties considering severe plasticity.

scholarly journals Experimental and Computational analysis of springback in dual phase steels

2021 ◽  
Vol 26 (2) ◽  
pp. 137-145
Author(s):  
Rodolfo Rodríguez Baracaldo ◽  
Yeison Parra-Rodríguez ◽  
José Manuel Arroyo-Osorio
Keyword(s):  
Elastic Recovery ◽  
Plastic Anisotropy ◽  
Microstructural Analysis ◽  
Rolling Direction ◽  
Experimental Tests ◽  
Tensile Tests ◽  
Bending Test ◽  
Uniaxial Tensile ◽  
Dual Phase ◽  
Characteristic Region

In this work the comfortability of dual-phase automotive steel DP600 is studied through uniaxial tensile tests and V-die bending tests in different directions relative to the rolling direction. A microstructural analysis was also carried out in each characteristic region of the deformation zone, evidencing the changes in the morphology of the microstructure grains. Additionally, the plastic anisotropy of the material was studied by implementing the constitutive anisotropy models known as Hill-48 and Barlat-89. The results showed an increase in elastic recovery at 45 ° and 90 ° from the rolling direction. This variation can be attributed to the morphology of the martensite that created preferential location zones within the material during the rolling process. The two models Hill-48 and Barlat-89 correctly describe the yield surface and the plastic anisotropy obtained in the experimental tests carried out. The simulation using the finite element method and the Hill-48 model gave satisfactory results in the prediction of the elastic recovery as compared to the experimental results obtained with the V-die bending test.

scholarly journals Future-Oriented Experimental Characterization of 3D Printed and Conventional Elastomers Based on Their Swelling Behavior

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4402
Author(s):  
Klara Loos ◽  
Vivianne Marie Bruère ◽  
Benedikt Demmel ◽  
Yvonne Ilmberger ◽  
Alexander Lion ◽  
...  
Keyword(s):  
Tensile Tests ◽  
Swelling Behavior ◽  
Uniaxial Tensile ◽  
Stress And Strain ◽  
Experimental Characterization ◽  
Synthetic Fuels ◽  
Fuel Component ◽  
3D Printed ◽  
Fuel Components

The present study investigates different elastomers with regard to their behavior towards liquids such as moisture, fuels, or fuel components. First, four additively manufactured materials are examined in detail with respect to their swelling in the fuel component toluene as well as in water. The chemical nature of the materials is elucidated by means of infrared spectroscopy. The experimentally derived absorption curves of the materials in the liquids are described mathematically using Fick’s diffusion law. The mechanical behavior is determined by uniaxial tensile tests, which are evaluated on the basis of stress and strain at break. The results of the study allow for deriving valuable recommendations regarding the printing process and postprocessing. Second, this article investigates the swelling behavior of new as well as thermo-oxidatively aged elastomers in synthetic fuels. For this purpose, an analysis routine is presented using sorption experiments combined with gas chromatography and mass spectrometry and is thus capable of analyzing the swelling behavior multifacetted. The transition of elastomer constituents into the surrounding fuel at different aging and sorption times is determined precisely. The change in mechanical properties is quantified using density measurements, micro Shore A hardness measurements, and the parameters stress and strain at break from uniaxial tensile tests.

Experimental Analysis of Forming Limits and Thickness Strains of DP600-800 Steels

2016 ◽  
Vol 835 ◽  
pp. 230-235 ◽  
Author(s):  
Marcelo Costa Cardoso ◽  
Alexandre de Melo Pereira ◽  
Fabiane Roberta Freitas da Silva ◽  
Luciano Pessanha Moreira
Keyword(s):  
Shear Failure ◽  
Plastic Anisotropy ◽  
Rolling Direction ◽  
Tensile Tests ◽  
Plastic Instability ◽  
Tensile Fracture ◽  
Forming Limit ◽  
Uniaxial Tensile ◽  
Plastic Behavior ◽  
Fractured Surface

In this work, the plastic behavior of cold-rolled zinc coated dual-phase steel sheets DP600 and DP800 grades is firstly investigated by means of uniaxial tensile and Forming Limit Curve (FLC) testing. The uniaxial tensile tests were carried out at 0o, 45o and 90o angular orientations with respect to the rolling direction to evaluate the mechanical properties and the plastic anisotropy Lankford r-values. The forming limit strains are defined according to Nakajima’s procedure. Thickness measurements of tested Nakajima’s samples cut perpendicular to the fracture allowed to identify a rapid decrease of the strain, which governs the plastic instability that preceded the fracture in the drawing region of the FLC. Optical metallographic and scanning electron microscopy techniques helped to characterize and distinguish the orientation of rotated grains and flat fractured surface (ductile shear failure in blank specimens close to plane-strain tension) from no grain rotations and rough fractured surface (ductile tensile fracture in blank geometries in the biaxial stretching domain).

Heterogeneous Biaxial Tensile Tests For The Characterization Of Sheet Metals Plastic Anisotropy

2011 ◽  
Author(s):  
M. Teaca ◽  
M. Martiny ◽  
I. Charpentier ◽  
G. Ferron ◽  
Francisco Chinesta ◽  
...  
Keyword(s):  
Plastic Anisotropy ◽  
Tensile Tests ◽  
Sheet Metals ◽  
Biaxial Tensile

Hyperelastic characterization of synthetic mesh for abdominal wall hernia repair

MRS Advances ◽  
2019 ◽  
Vol 4 (57-58) ◽  
pp. 3181-3185
Author(s):  
Javier Ortiz Ortiz ◽  
Georgina Carbajal de la Torre ◽  
Miguel Villagómez Galindo ◽  
Marco Antonio Espinosa Medina ◽  
Hilda Aguilar Rodriguez
Keyword(s):  
Hernia Repair ◽  
Abdominal Wall ◽  
Abdominal Wall Hernia ◽  
Tensile Tests ◽  
Synthetic Mesh ◽  
Uniaxial Tensile ◽  
Marquardt Algorithm ◽  
Hyperelastic Model ◽  
Abdominal Wall Hernia Repair

ABSTRACTHernia is defined as the protrusion of one or several internal organs through an opening in the cavity that contains them due to a tissue defect, abdominal wall surgery by means of synthetic meshes is the most common method used for hernia repair, however, postsurgical effects can range from some discomfort, to chronic pain and even the reappearance of the hernia due to a poor mechanical adaptability between the synthetic tissue and the host tissue. The knowledge of the mechanical properties of the materials involved in hernia repair is fundamental in the understanding and subsequent solution of this type of problems. In this work, experimental data were obtained by means of uniaxial tensile tests in two perpendicular directions of commercial meshes used in hernia repair. The tests were carried out on the UniVert® machine of the CellScale® brand. Anisotropic mechanical behavior is observed due to the structure of the mesh and the interaction between each of the yarns that make it up. The data found vary with respect to the direction of traction and also has non-linear hyperelastic behavior, so the adjustment of curves was made through a hyperelastic model in the COMSOL Multiphysics® software through the Levenberg-Marquardt Algorithm for the characterization of these materials.

Sign in / Sign up

Export Citation Format

Share Document