Elastic-plastic properties evaluation of copper by micro-indentation tests

2000 ◽  
Vol 2000 (0) ◽  
pp. 593-594
Author(s):  
Chikao KURAMOCHI ◽  
Norimasa CHIBA ◽  
Nagahisa OGASAWARA
2013 ◽  
Vol 592-593 ◽  
pp. 610-613
Author(s):  
Sina Amiri ◽  
Nora Lecis ◽  
Andrea Manes ◽  
Davide Mombelli ◽  
Marco Giglio

Different approaches have been proposed in order to determine the material behavior of ductile materials. Since, the mechanical properties of a mechanical component are modified during manufacturing process due to plastic deformation, heat treatment and etc, a non-destructive indentation experimental procedure addressed to predict the elastic-plastic properties of material after manufacturing process is of interest. This is especially true for small size components where it is complex to extract specimens to test on standard test system. Based on dimensionless analysis and the concept of a representative strain, different approaches have been proposed to determine the material properties of power law materials by using indentation process. In this work, the Johnson-Cook (JC) constitutive model of the aluminum alloy Al6061-T6 is characterized by means of a well-defined optimization procedure based on micro-indentation testing and high fidelity finite element models and an optimization procedure but without the concept of dimensionless analysis and a representative strain. This methodology allows determining a set of JC constants for Al6061-T6. The obtained results have good agreement with parameters calibrated by means of universal standard tests and reverse engineering approach.


2019 ◽  
Vol 26 (07) ◽  
pp. 1850225
Author(s):  
YONG MA ◽  
ZHAO YANG ◽  
SHENGWANG YU ◽  
BING ZHOU ◽  
HONGJUN HEI ◽  
...  

The aim of this paper is to establish an approach to quantitatively determine the elasto-plastic parameters of the Mo-modified Ti obtained by the plasma surface alloying technique. A micro-indentation test is conducted on the surface under 10[Formula: see text]N. Considering size effects, nanoindentation tests are conducted on the cross-section with two loads of 6 and 8[Formula: see text]mN. Assuming nanoindentation testing sublayers are homogeneous, finite element reverse analysis is adopted to determine their plastic parameters. According to the gradient distributions of the elasto-plastic parameters with depth in the Mo-modified Ti, two types of mathematical expressions are proposed. Compared with the polynomial expression, the linear simplified expression does not need the graded material to be sectioned and has practical utility in the surface treatment industry. The validation of the linear simplified expression is verified by the micro-indentation test and corresponding finite element forward analysis. This approach can assist in improving the surface treatment process of the Mo-modified Ti and further enhancing its load capacity and wear resistance.


2006 ◽  
Vol 326-328 ◽  
pp. 361-364
Author(s):  
Yun Jae Kim ◽  
Tae Kwang Song ◽  
Jun Hee Hanh ◽  
Jun Hyub Park

This paper discusses possibilities to extract elastic-plastic properties of nano-scale materials using combined nano-indentation tests with FE simulations. One interesting finding is that FE simulations of nano-indentation with a number of different plastic properties give same load-displacement response, which suggests that plastic properties cannot be determined from simulating load-depth curves from nano-indentation tests. However, careful examination of possible plastic properties suggests a concept of the reference strain, which makes it possible to effectively determine plastic properties from nano-indentation tests with FE simulations.


2011 ◽  
Vol 46 (8) ◽  
pp. 749-759 ◽  
Author(s):  
J J Kang ◽  
A A Becker ◽  
W Sun

Loading–unloading curves obtained from indentation experiments can be used to extract elastic-plastic mechanical properties using the finite element (FE) method. However, extensive computation times are required in such an approach due to the fact that the optimization procedure is based on iterative FE computations. In this study, a combined dimensional analysis and optimization approach is developed for the determination of the elastic-plastic mechanical properties of power law materials, without the need for iterative FE analysis. A parametric study using FE analysis is first conducted to construct the appropriate dimensional functions. The optimization algorithm with either a single indenter or dual indenters is then used to obtain the material properties from the given loading–unloading curves. Different sets of materials properties are used and the accuracy and validity of the predicted mechanical properties using the single indenter or dual indenters are assessed.


Author(s):  
Y. C. Lu ◽  
D. M. Shinozaki

Large displacement micro-indentation tests have been performed on various polymeric solids to measure the plastic properties. Cylindrical flat-ended indenters with diameter in the range of 10–90 μm are mostly used. The mechanism of large-strain indentation has been examined with optical microscopy and finite element simulations. Results show that under a flat-tipped indenter, the material can quickly reach a fully plastic state. The size (diameter) of the plastic zone is constant in large-strain regions and unaffected by the exact tip profile (flat, spherical, and conical). The indentation stress-displacement curve at large strains is linear as a result of the steady-state plastic flow, from which the mean indentation pressure, a measure of yield strength, can be readily extrapolated. The indentation stress-displacement response is independent of the indenter diameters but strongly dependent on the strain-hardening behavior of the material and the friction between a material and an indenter. Compared with other shaped indenters, the flat-ended indenter requires the least penetration depth in order to probe the plastic properties of a material or structure.


Symmetry ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 145
Author(s):  
Sergei Alexandrov ◽  
Elena Lyamina ◽  
Yeong-Maw Hwang

The present paper concerns the general solution for finite plane strain pure bending of incompressible, orthotropic sheets. In contrast to available solutions, the new solution is valid for inhomogeneous distributions of plastic properties. The solution is semi-analytic. A numerical treatment is only necessary for solving transcendent equations and evaluating ordinary integrals. The solution’s starting point is a transformation between Eulerian and Lagrangian coordinates that is valid for a wide class of constitutive equations. The symmetric distribution relative to the center line of the sheet is separately treated where it is advantageous. It is shown that this type of symmetry simplifies the solution. Hill’s quadratic yield criterion is adopted. Both elastic/plastic and rigid/plastic solutions are derived. Elastic unloading is also considered, and it is shown that reverse plastic yielding occurs at a relatively large inside radius. An illustrative example uses real experimental data. The distribution of plastic properties is symmetric in this example. It is shown that the difference between the elastic/plastic and rigid/plastic solutions is negligible, except at the very beginning of the process. However, the rigid/plastic solution is much simpler and, therefore, can be recommended for practical use at large strains, including calculating the residual stresses.


2010 ◽  
Vol 103 (2) ◽  
pp. 493-496 ◽  
Author(s):  
S. K. Deb Nath ◽  
Hironori Tohmyoh ◽  
M. A. Salam Akanda

Sign in / Sign up

Export Citation Format

Share Document