The Determination of Stress-Strain Curves of Thin Layers Using Indentation Tests

1986 ◽  
Vol 108 (3) ◽  
pp. 230-232 ◽  
Author(s):  
A. G. Tangena ◽  
G. A. M. Hurkx

A method is presented for estimating the plastic part of stress-strain curves of metal coatings, using a Brinell indentation test. The accuracy of the stress-strain curves obtained in this way is tested by using these curves in a finite element calculation and comparing the calculated results with results from experiments. Stress-strain curves are given for galvanic layers such as citrate Au, Co-Au, sulfamate Ni and also for solid annealed pure Au.

2004 ◽  
Vol 841 ◽  
Author(s):  
Karsten Durst ◽  
Björn Backes ◽  
Mathias Göken

ABSTRACTThe determination of plastic properties of metallic materials by nanoindentation requires the analysis of the indentation process and the evaluation methods. Particular effects on the nanoscale, like the indentation size effect or piling up of the material around the indentation, need to be considered. Nanoindentation experiments were performed on conventional grain sized (CG) as well as on ultrafine-grained (UFG) copper and brass. The indentation experiments were complemented with finite element simulations using the monotonic stress-strain curve as input data. All indentation tests were carried out using cube-corner and Berkovich geometry and thus different amount of plastic strain was applied to the material, according to Tabors theory. We find an excellent agreement between simulations and experiments for the UFG materials from which a representative strain of εB ≈ 0.1 and εcc ≈ 0.2 is determined. With these data, the slope of the stress-strain curve is predicted for all materials down to an indentation depth of 800 nm.


2013 ◽  
Vol 804 ◽  
pp. 320-324
Author(s):  
Xiang Zan Xie

This paper adopts universal finite element calculation software to carry out finite element analysis for Tianerya trench-buried inverted siphon. Researching variation law of the inverted siphons stress and displacement in construction process and operational process. The calculation results further shown design schemes rationality and safety. The analysis results provide a certain reference for design of trench-buried inverted siphon structure.


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.


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