On the Measurement of Stress-Strain Curves by Spherical Indentation

2000 ◽  
Vol 649 ◽  
Author(s):  
E. G. Herbert ◽  
G. M. Pharr ◽  
W. C. Oliver ◽  
B. N. Lucas ◽  
J. L. Hay
Keyword(s):  
Aluminum Alloy ◽  
Uniaxial Tension ◽  
Indentation Test ◽  
Uniaxial Stress ◽  
Analytical Models ◽  
Test Material ◽  
Spherical Indentation ◽  
Stress Strain ◽  
Strain Behavior ◽  
Instrumented Indentation Test

AbstractIt has been proposed that with the appropriate models, instrumented indentation test (IIT) data can be reduced to yield the uniaxial stress-strain behavior of the test material. However, very little work has been done to directly compare the results from uniaxial tension and spherical indentation experiments. In this work, indentation and uniaxial tension experiments have been performed on the aluminum alloy 6061-T6. The purpose of these experiments was to specifically explore the accuracy with which the analytical models can be applied to IIT data to predict the uniaxial stress-strain behavior of the aluminum alloy.

Determining engineering stress–strain curve directly from the load–depth curve of spherical indentation test

2010 ◽  
Vol 25 (12) ◽  
pp. 2297-2307 ◽  
Author(s):  
Baoxing Xu ◽  
Xi Chen
Keyword(s):  
Indentation Test ◽  
Strain Curve ◽  
Spherical Indentation ◽  
Displacement Curve ◽  
Large Set ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Constraint Factors ◽  
Engineering Stress ◽  
Depth Curve

The engineering stress–strain curve is one of the most convenient characterizations of the constitutive behavior of materials that can be obtained directly from uniaxial experiments. We propose that the engineering stress–strain curve may also be directly converted from the load–depth curve of a deep spherical indentation test via new phenomenological formulations of the effective indentation strain and stress. From extensive forward analyses, explicit relationships are established between the indentation constraint factors and material elastoplastic parameters, and verified numerically by a large set of engineering materials as well as experimentally by parallel laboratory tests and data available in the literature. An iterative reverse analysis procedure is proposed such that the uniaxial engineering stress–strain curve of an unknown material (assuming that its elastic modulus is obtained in advance via a separate shallow spherical indentation test or other established methods) can be deduced phenomenologically and approximately from the load–displacement curve of a deep spherical indentation test.

Elastomer Behavior IV. Loop Structure of Elastomer Networks

1966 ◽  
Vol 39 (5) ◽  
pp. 1489-1495
Author(s):  
L. C. Case ◽  
R. V. Wargin
Keyword(s):  
Experimental Data ◽  
Crosslink Density ◽  
Strain Curve ◽  
Uniaxial Stress ◽  
Polymer Chains ◽  
Theoretical Treatment ◽  
Loop Structure ◽  
Stress Strain ◽  
Strain Behavior ◽  
Selection Of

Abstract A new theoretical treatment strongly indicates that an elastomer network actually consists of a system of fused, closed, interpenetrating loops of polymer chains. This interpenetrating loop structure restricts the movement of the chains and thereby affects the stress-strain behavior of the elastomer. Methods have been developed to enable the calculation of the number of effective crosslinks caused by loop interpenetrations (virtual crosslinks). The uniaxial stress-strain behavior of an elastomer predicted using our methods can be fitted almost perfectly to published experimental data by proper selection of chain parameters. Previous theoretical treatments gave only a qualitative fit to the experimental data for the stress-strain behavior of elastomers and were not capable of predicting the correct shape of the experimental stress-strain curve. The present treatment gives a nearly perfect fit for both stress as a function of strain at constant crosslink density, and stress as a function of crosslink density at constant strain, and thus represents a vast improvement.

scholarly journals Stress–Strain Behavior of FRC in Uniaxial Tension Based on Mesoscopic Damage Model

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 689
Author(s):  
Weifeng Bai ◽  
Xiaofeng Lu ◽  
Junfeng Guan ◽  
Shuang Huang ◽  
Chenyang Yuan ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Uniaxial Tension ◽  
Damage Evolution ◽  
Constitutive Relations ◽  
Damage Mechanism ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Stress Strain ◽  
Strain Behavior ◽  
Nonlinear Stress

Fiber-reinforced concrete (FRC) is widely used in the field of civil engineering. However, the research on the damage mechanism of FRC under uniaxial tension is still insufficient, and most of the constitutive relations are macroscopic phenomenological. The aim is to provide a new method for the investigation of mesoscopic damage mechanism of FRC under uniaxial tension. Based on statistical damage theory, the damage constitutive model for FRC under uniaxial tension is established. Two kinds of mesoscopic damage mechanisms, fracture and yield, are considered, which ultimately determines the macroscopic nonlinear stress–strain behavior of concrete. The yield damage mode reflects the potential bearing capacity of materials and plays a key role in the whole process. Evolutionary factor is introduced to reflect the degree of optimization and adjustment of the stressed skeleton in microstructure. The whole deformation-to-failure is divided into uniform damage phase and local failure phase. It is assumed that the two kinds of damage evolution follow the independent triangular probability distributions, which could be represented by four characteristic parameters. The validity of the proposed model is verified by two sets of test data of steel fiber-reinforced concrete. Through the analysis of the variation law of the above parameters, the influence of fiber content on the initiation and propagation of micro-cracks and the damage evolution of concrete could be evaluated. The relations among physical mechanism, mesoscopic damage mechanism, and macroscopic nonlinear mechanical behavior of FRC are discussed.

Modeling of stress-strain relation of cement-treated sand under compression

2021 ◽  
Author(s):  
Khawaja Adeel Tariq ◽  
Takeshi Maki
Keyword(s):  
Research Work ◽  
Fixed Ratio ◽  
Uniaxial Stress ◽  
Limestone Powder ◽  
Compressive Behavior ◽  
Stress Strain ◽  
Element Analysis ◽  
Strain Behavior ◽  
Stress Strain Relation ◽  
Uniaxial Compressive Stress

AbstractThis research work has been conducted to model the uniaxial stress-strain compressive behavior of cement-treated sand and its post-peak softening area. The cylindrical specimens were produced by using limestone powder, sand and high early strength cement. The mixtures were made by using different ratios of water to cement with fixed ratio of limestone powder to cement and cement to sand. The stress-strain behavior in post-peak zone of cement-treated is adjusted with introduction of compression softening factor. Uniaxial compressive stress-strain relationships after amending the Japanese Society of Civil Engineers model are proposed. Finite element analysis shows that the suggested model estimates well the compressive behavior of cement-treated sand.

Uniaxial Stress-Strain Model for Concrete Confined by Rectangular Steel Tubes

2010 ◽  
Vol 163-167 ◽  
pp. 1005-1011
Author(s):  
Yue Ling Long ◽  
Jian Cai
Keyword(s):  
Triaxial Compression ◽  
Uniaxial Stress ◽  
Failure Criteria ◽  
Steel Tube ◽  
Test Results ◽  
Stress Strain ◽  
Steel Tubes ◽  
Concrete Core ◽  
Strain Behavior ◽  
The Difference

This paper presents a new model for uniaxial stress-strain relationship of concrete confined by rectangular steel tubes. The difference between concrete confinement effect provided by broad faces and that provided by narrow faces of steel tube is considered in the proposed model. The failure criteria for concrete subjected to triaxial compression is applied to estimate the ultimate strength of concrete core. The parameters of the model are determined based on the test results and the calculation of complete load-stress relationship curves is conducted for axially loaded rectangular CFT specimens using the model proposed in the paper. The concrete core strength and stress-strain behavior of rectangular CFT columns is found to exhibit good agreement with test results.

Determining Stress-Strain Behavior of Zr60Cu10Al15Ni15 Bulk Metallic Glass Using Object Oriented Finite Element Analysis

2017 ◽  
Vol 29 ◽  
pp. 1-8 ◽  
Author(s):  
Ketul Arvindbhai Patel ◽  
Ganesh R. Karthikeyan ◽  
S. Vincent
Keyword(s):  
Mechanical Properties ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Metallic Glass ◽  
Strain Analysis ◽  
Indentation Test ◽  
Object Oriented ◽  
Stress Strain ◽  
Element Analysis ◽  
Strain Behavior

Determining mechanical properties of Bulk Metallic Glasses (BMGs) requires synthesizing of the alloys in bulk form. However obtaining metallic glass in bulk form is quite challenging due to its tendency towards crystallization. In such circumstances it is beneficial to determine the mechanical properties of materials using finite elemental analysis of microstructures. Thus, in the present investigation, using Object Oriented Finite Element Analysis (OOF2) software package, Stress-Strain analysis has been carried out on Zr60Cu10Al15Ni15 BMG to determine such mechanical properties. Specimen of Zr60Cu10Al15Ni15 BMG exhibiting three microstructurally distinct regions amorphous, partial crystalline and crystalline regions was used for this analysis. The Stress-Strain relationship have been estimated for each of the three distinct phases and the results are validated by determining the Modulus of Elasticity for all the phases and comparing it with the available experimental results from Nano-indentation test.

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