A Bayesian inverse approach to measure the anisotropic plasticity properties of materials using spherical indentation experiment

Measurement ◽  
2021 ◽  
Vol 171 ◽  
pp. 108812
Author(s):  
Mingzhi Wang ◽  
Libo Gao ◽  
Ke Cao ◽  
Jianjun Wu ◽  
Weidong Wang
Keyword(s):  
Spherical Indentation ◽  
Anisotropic Plasticity ◽  
Inverse Approach ◽  
Indentation Experiment ◽  
Properties Of Materials

scholarly journals Numerical verification for instrumented spherical indentation techniques in determining the plastic properties of materials

2009 ◽  
Vol 24 (12) ◽  
pp. 3653-3663 ◽  
Author(s):  
Taihua Zhang ◽  
Peng Jiang ◽  
Yihui Feng ◽  
Rong Yang
Keyword(s):  
Numerical Experiments ◽  
Spherical Indentation ◽  
Numerical Verification ◽  
Instrumented Indentation ◽  
Plastic Properties ◽  
Wide Range ◽  
Validity Range ◽  
Indentation Tests ◽  
Properties Of Materials ◽  
Indentation Methods

Instrumented indentation tests have been widely adopted for elastic modulus determination. Recently, a number of indentation-based methods for plastic properties characterization have been proposed, and rigorous verification is absolutely necessary for their wide application. In view of the advantages of spherical indentation compared with conical indentation in determining plastic properties, this study mainly concerns verification of spherical indentation methods. Five convenient and simple models were selected for this purpose, and numerical experiments for a wide range of materials are carried out to identify their accuracy and sensitivity characteristics. The verification results show that four of these five methods can give relatively accurate and stable results within a certain material domain, which is defined as their validity range and has been summarized for each method.

A Combined Numerical and Experimental Approach to Evaluate the Hardness of AA Aluminum 6063 T6 with A Ni-P Coating

2019 ◽  
Vol 827 ◽  
pp. 209-215
Author(s):  
B. Juan S. León ◽  
Alberto Pertuz ◽  
M. Martínez
Keyword(s):  
Experimental Data ◽  
Experimental Approach ◽  
Brinell Hardness ◽  
Indentation Test ◽  
Contact Radius ◽  
Spherical Indentation ◽  
The Finite Element Method ◽  
Hard Materials ◽  
A Value ◽  
Properties Of Materials

The need to improve the surface properties of materials, has led to the development of parts coated with hard materials deposited on substrates. In this work, by using the finite element method the AA Aluminium 6063 T6 hardness with an error less of the 5 % of the Brinell hardness (HBN), in comparison with the experimental data supplied, was determined. For this, the modelling of a spherical indentation test was carried out, in which the indentation loads and the projected contact radius are obtained from several potential adjustments. Then, using the Lessage-Pertúz model the hardness of the Ni-P coating was determined, obtaining a value of 4.86 GPa.

Determination of the proof strength and flow properties of materials from spherical indentation tests: An analytical approach based on the expanding cavity model

2018 ◽  
Vol 53 (4) ◽  
pp. 225-241 ◽  
Author(s):  
Tairui Zhang ◽  
Shang Wang ◽  
Weiqiang Wang
Keyword(s):  
Finite Element ◽  
Calculation Method ◽  
Force Balance ◽  
Spherical Indentation ◽  
Cavity Model ◽  
Flow Properties ◽  
Finite Element Calculations ◽  
Indentation Tests ◽  
Properties Of Materials ◽  
Proof Strength

An analytical method based on the extended expanding cavity model was proposed in this study to determine the proof strength Rp0.2 and flow properties of materials that obey the Johnson–Cook constitutive model from spherical indentation tests. The introduction of the Johnson–Cook model made the proposed method suitable for the tensile property evaluation of materials not only at room temperature but also at elevated temperatures. The validity of the expanding cavity model was verified through comparisons of von Mises equivalent strain distributions obtained from finite element analyses with the corresponding results from theoretical analysis. From the parameter analysis, it was found that the indentation governing parameter ψempirical in the empirical method was actually determined by the tangential modulus Ep and the hardening exponent n and thus should not be considered as a constant. We also analyzed the unreliability of previous plastic zone radius rp calculation method at large indentation depths (with obvious pileup phenomenon) and put forward a new calculation method of rp based on the force balance. Finite element calculations of spherical indentation tests with tensile properties of Ti6Al4V and AISI 4340 were conducted in this study as substitutes for spherical indentation tests. The load–depth data and rp from finite element calculations were employed in the reverse analysis, the results of which showed that spherical indentation tests can provide the same reliable Rp0.2 as tensile tests and even the whole stress–strain curves. Furthermore, the influence of friction and the measuring system strain threshold in the measurement of rp, which may be inevitable in experiments, were also thoroughly discussed in this study, which also helped to verify the robustness of this study.

A Novel Method to Extract the Plastic Properties of Metal Materials from a Continuous Spherical Indentation Test

2017 ◽  
Vol 734 ◽  
pp. 206-211 ◽  
Author(s):  
Zhuang Jin ◽  
Jian Ping Zhao
Keyword(s):  
Strain Hardening ◽  
Indentation Test ◽  
New Method ◽  
Spherical Indentation ◽  
Strain Hardening Exponent ◽  
Computational Results ◽  
Plastic Properties ◽  
Novel Method ◽  
Properties Of Materials ◽  
Metal Materials

Cao and Lu had built a method to acquire the properties of materials. But they neglected the influence of strain hardening exponent n by introducing the representative strain which didan’t have any physical meaning. A new method from a continuous spherical indentation test was built, the influence of strain hardening exponent n were considered and the formulas of dimensionless functions defined in their work were improved in this present paper. Then the computational results from the new method and the actual results were compared and the error is about 8%.

On the sensitivity characteristics in the determination of the elastic and plastic properties of materials through multiple indentation

2007 ◽  
Vol 22 (4) ◽  
pp. 1043-1063 ◽  
Author(s):  
Hongzhi Lan ◽  
T.A. Venkatesh
Keyword(s):  
Spherical Indentation ◽  
Plastic Properties ◽  
Reverse Analysis ◽  
Properties Of Materials ◽  
Sharp Indentation ◽  
Comprehensive Study

A comprehensive study of the sensitivity characteristics associated with the determination of the elasto-plastic properties of a large number of materials using several combinations of dual, triple, and quadruple sharp indentation, and spherical indentation illustrates that: (i) The lowest sensitivity to the determination of plastic properties is observed for the indenter combination that corresponds either to the largest difference in the corresponding representative stresses or the largest difference in the indenter apex angles. (ii) The triple or quadruple sharp indenter combinations considered in the present study do not show a significant improvement in the sensitivity characteristics when compared to that of the dual sharp indentation. (iii) In the determination of plastic properties through spherical indentation where two representative stresses are invoked, the highest and the lowest sensitivity, respectively, are observed for the combinations in which the differences in the representative stresses are the lowest and the highest. The sensitivity is further reduced if a large number of representative stresses are considered for the reverse analysis.

scholarly journals An Inverse Method for Measuring Elastoplastic Properties of Metallic Materials Using Bayesian Model and Residual Imprint from Spherical Indentation

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7105
Author(s):  
Mingzhi Wang ◽  
Weidong Wang
Keyword(s):  
Inverse Method ◽  
Measuring Method ◽  
Indentation Load ◽  
Weighting Coefficient ◽  
Spherical Indentation ◽  
Model Parameters ◽  
Metallic Materials ◽  
Elastoplastic Properties ◽  
Indentation Experiment ◽  
Tensile Experiment

In this paper, an inverse method is proposed for measuring the elastoplastic properties of metallic materials using a spherical indentation experiment. In the new method, the elastoplastic parameters are correlated with sub-space coordinates of indentation imprints using proper orthogonal decomposition (POD), and inverse identification of material properties is solved using a statistical Bayesian framework. The advantage of the method is that model parameters in the numerical optimization process are treated as the stochastic variables, and potential uncertainties can be considered. The posterior results obtained from the measuring method can provide valuable probabilistic information of the estimated elastoplastic properties. The proposed method is verified by the application on 2099-T83 Al-Li alloys. Results indicate that posterior distribution of material parameters exhibits more than one peak region when indentation load is not large enough. In addition, using the weighting imprints under different loads can facilitate the uniqueness in identification of elastoplastic parameters. The influence of the weighting coefficient on posterior identification results is analyzed. The elastoplastic properties identified by indentation and tensile experiment show good agreement. Results indicate that the established measuring method is effective and reliable.

Spherical Indentation Testing of Polymers at Various Temperatures

2001 ◽  
Vol 695 ◽  
Author(s):  
Vincent D. Jardret ◽  
Pierre Morel ◽  
Nicolas Conté
Keyword(s):  
Polymeric Materials ◽  
Spherical Indentation ◽  
Indentation Testing ◽  
Stress Strain ◽  
Topographic Analysis ◽  
Strain Behavior ◽  
Strain Relationship ◽  
Indentation Experiment ◽  
The Subject ◽  
The Relationship

ABSTRACTContact mechanics for indentation testing with spherical indenter is very attractive. Numerous projects have established equations to define strain and stress distribution in order to obtain stress-strain relationship from a single indentation experiment. Also a large number of studies have focused on metallic materials with the objective of estimating the yield point.The subject of this work is to analyze the behavior of various polymeric materials during spherical indentation testing at various temperature in order to observe the relationship between the indentation behavior and compression stress-strain behavior of the same materials as a function of temperature. Thermal effects on the indentation data are used to understand the actual effects of the mechanical properties on the indentation behavior. In addition to the load, displacement, and frequency specific stiffness information, topographic analysis of the residual indentation print is used to accurately estimate the contact area, therefore, validate the indentation models for contact depth calculations using spherical indentation. Results presented in this article include spherical indentation data obtained on PMMA and Polycarbonate over a range of temperature from 5°C to l00°C.

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