Evaluation of Micro-Pillar Compression Tests for Accurate Determination of Elastic-Plastic Constitutive Relations

2012 ◽  
Vol 79 (6) ◽  
Author(s):  
Huiyang Fei ◽  
Amit Abraham ◽  
Nikhilesh Chawla ◽  
Hanqing Jiang
Keyword(s):  
Mechanical Properties ◽  
Finite Element Analysis ◽  
Compression Test ◽  
Constitutive Relations ◽  
Accurate Determination ◽  
Compression Tests ◽  
Element Analysis ◽  
Plastic Materials ◽  
Properties Of Materials

The micro-pillar compression test is emerging as a novel way to measure the mechanical properties of materials. In this paper, we systematically conducted finite element analysis to evaluate the capability of using a micro-compression test to probe the mechanical properties of both elastic and plastic materials. We found that this test can provide an alternative way to accurately and robustly measure strain, and to some extent, stress. Therefore, this test can be used to measure some strain related quantities, such as strain to failure, or the stress-strain relations for plastic materials.

Polyurethane Foams Behaviour. Experiments versus Modeling

2008 ◽  
Vol 399 ◽  
pp. 123-130 ◽  
Author(s):  
Liviu Marsavina ◽  
Tomasz Sadowski ◽  
Dan Mihai Constantinescu ◽  
Radu Negru
Keyword(s):  
Mechanical Properties ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Polyurethane Foam ◽  
Polyurethane Foams ◽  
Experimental Program ◽  
High Porosity ◽  
Compression Tests ◽  
Element Analysis ◽  
Micromechanical Models

. Polyurethane foam materials are widely used as cores in sandwich composites, for packing and cushioning. The main characteristics of foams are light weight, high porosity, high crushability and good energy absorption capacity. The paper presents the experimental results obtained for the mechanical properties of polyurethane foams in different loading conditions and the influence of impregnation on the mechanical properties. A 200 kg/m3 density polyurethane foam was investigated in the experimental program in three different Strength of Materials laboratories from Lublin, Bucharest and Timisoara. The paper assesses the possibility to describe the polyurethane foam behaviour trough compression tests, micromechanical models and Finite Element Analysis (FEA). The micromechanical models and Finite Element Analysis could be used successfully for representing the engineering stress – strain behaviour if the compression tests provide reliable material parameters.

scholarly journals Numerical investigation of the mechanical properties of the additive manufactured bone scaffolds fabricated by FDM: the effect of layer penetration and post-heating

2017 ◽  
Author(s):  
Saman Naghieh ◽  
Mohammad Reza Karamooz-Ravari ◽  
Mohsen Badrossamay ◽  
Ehsan Foroozmehr
Keyword(s):  
Mechanical Properties ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Elastic Modulus ◽  
Numerical Methods ◽  
Finite Element Model ◽  
Compression Test ◽  
Element Model ◽  
Element Analysis ◽  
Bone Scaffolds

In recent years, thanks to additive manufacturing technology, researchers have gone towards the optimization of bone scaffolds for the bone reconstruction. Bone scaffolds should have appropriate biological as well as mechanical properties in order to play a decisive role in bone healing. Since the fabrication of scaffolds is time consuming and expensive, numerical methods are often utilized to simulate their mechanical properties in order to find a nearly optimum one. Finite element analysis is one of the most common numerical methods that is used in this regard. In this paper, a parametric finite element model is developed to assess the effects of layers penetration׳s effect on inter-layer adhesion, which is reflected on the mechanical properties of bone scaffolds. To be able to validate this model, some compression test specimens as well as bone scaffolds are fabricated with biocompatible and biodegradable poly lactic acid using fused deposition modeling. All these specimens are tested in compression and their elastic modulus is obtained. Using the material parameters of the compression test specimens, the finite element analysis of the bone scaffold is performed. The obtained elastic modulus is compared with experiment indicating a good agreement. Accordingly, the proposed finite element model is able to predict the mechanical behavior of fabricated bone scaffolds accurately. In addition, the effect of post-heating of bone scaffolds on their elastic modulus is investigated. The results demonstrate that the numerically predicted elastic modulus of scaffold is closer to experimental outcomes in comparison with as-built samples.

Determination of Stiffness Properties of Single-Ply Cord-Rubber Composites

1988 ◽  
Vol 16 (2) ◽  
pp. 118-126 ◽  
Author(s):  
S. Parhizgar ◽  
E. M. Weissman ◽  
C. S. Chen
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Accurate Determination ◽  
Rubber Composites ◽  
Element Analysis ◽  
Stiffness Properties ◽  
The Finite Element Analysis ◽  
Adequate Accuracy ◽  
Accuracy Determination

Abstract Accurate determination of stiffness properties of cord-rubber composites is a key to successful finite element analysis of tires. The Halpin-Tsai and similar equations which are used to determine stiffness properties of cord-rubber single plies from the stiffness properties of cord and rubber do not provide adequate accuracy. Determination of these properties from strains directly measured by the Moire technique is more appropriate. In this paper the disadvantages of Halpin-Tsai and similar equations as well as the advantages of the Moire technique for cord-rubber composites are discussed. The stiffness properties obtained using the above different methods are compared. These stiffness properties are then used in the finite element analysis of a two-ply cord-rubber strip. The results of the finite element analyses are compared with experimental data.

Finite Element Analysis of Reinforced Concrete Beams with Exterior FRP Shell

2011 ◽  
Vol 243-249 ◽  
pp. 1461-1465
Author(s):  
Chuan Min Zhang ◽  
Chao He Chen ◽  
Ye Fan Chen
Keyword(s):  
Mechanical Properties ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Reinforced Concrete ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Test Results ◽  
Contact Interface ◽  
Accurate Calculation ◽  
Element Analysis

The paper makes an analysis of the reinforced concrete beams with exterior FRP Shell in Finite Element, and compares it with the test results. The results show that, by means of this model, mechanical properties of reinforced concrete beams with exterior FRP shell can be predicted better. However, the larger the load, the larger deviation between calculated values and test values. Hence, if more accurate calculation is required, issues of contact interface between the reinforced concrete beams and the FRP shell should be taken into consideration.

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