Determination of elasto-plastic properties by instrumented sharp indentation: guidelines for property extraction

Venkatesh, T. A.; Vliet, Krystyn J. Van; Giannakopoulos, A.E.; Suresh, S.

doi:10.1016/s1359-6462(00)00311-0

Cited by 204 publications

(108 citation statements)

References 1 publication

Supporting

Mentioning

102

Contrasting

Unclassified

Order By: Relevance

“…Concurrently, comprehensive theoretical and computational studies have emerged to elucidate the contact mechanics and deformation mechanisms in order to systematically extract material properties from P versus h curves obtained from instrumented indentation (e.g., [3,5,11,12,[16][17][18][19][20][21]). For example, the hardness and Young's modulus can be obtained from the maximum load and the initial unloading slope using the methods suggested by Oliver and Pharr [5] or Doerner and Nix [3].…”

Section: Introductionmentioning

confidence: 99%

Computational modeling of the forward and reverse problems in instrumented sharp indentation

et al. 2001

View full text Add to dashboard Cite

Abstract-A comprehensive computational study was undertaken to identify the extent to which elastoplastic properties of ductile materials could be determined from instrumented sharp indentation and to quantify the sensitivity of such extracted properties to variations in the measured indentation data. Large deformation finite element computations were carried out for 76 different combinations of elasto-plastic properties that encompass the wide range of parameters commonly found in pure and alloyed engineering metals: Young's modulus, E, was varied from 10 to 210 GPa, yield strength, s y , from 30 to 3000 MPa, and strain hardening exponent, n, from 0 to 0.5, and the Poisson's ratio, n, was fixed at 0.3. Using dimensional analysis, a new set of dimensionless functions were constructed to characterize instrumented sharp indentation. From these functions and elasto-plastic finite element computations, analytical expressions were derived to relate indentation data to elasto-plastic properties. Forward and reverse analysis algorithms were thus established; the forward algorithms allow for the calculation of a unique indentation response for a given set of elasto-plastic properties, whereas the reverse algorithms enable the extraction of elasto-plastic properties from a given set of indentation data. A representative plastic strain e r was identified as a strain level which allows for the construction of a dimensionless description of indentation loading response, independent of strain hardening exponent n. The proposed reverse analysis provides a unique solution of the reduced Young's modulus E*, a representative stress s r , and the hardness p ave . These values are somewhat sensitive to the experimental scatter and/or error commonly seen in instrumented indentation. With this information, values of s y and n can be determined for the majority of cases considered here, provided that the assumption of power law hardening adequately represents the full uniaxial stress-strain response. These plastic properties, however, are very strongly influenced by even small variations in the parameters extracted from instrumented indentation experiments. Comprehensive sensitivity analyses were carried out for both forward and reverse algorithms, and the computational results were compared with experimental data for two materials. 

show abstract

Section: Introductionmentioning

confidence: 99%

Computational modeling of the forward and reverse problems in instrumented sharp indentation

et al. 2001

View full text Add to dashboard Cite

show abstract

“…With the help of indentation tests carried out on different scales, a wide range of materials can be characterized: metals, alloys, ceramics, concrete [3] or even graded materials [4][5][6][7][8] and the test can also be applied to an actual structure without the need for cutting-out a specimen for tensile testing. Indentation-based assessment of material properties usually relies on the recorded force-displacement curve (P-h curve) [9][10][11][12] obtained in two main phases. In the loading phase, a hard indenter is pressed against the specimen surface.…”

Section: Introductionmentioning

confidence: 99%

“…It is also recommended to calculate the derivative of the indentation curve in order to limit the effects of a false determination of the zero position [31]. It has been shown that even a small noise in the input data makes the accurate identification of parameters difficult [11,12]. The indentation curve is observed to be mesh-dependent due to large oscillations with a coarse mesh [32].…”

Section: Introductionmentioning

confidence: 99%

Identification of material properties using indentation test and shape manifold learning approach

Liang

Breitkopf

Raghavan

et al. 2015

Computer Methods in Applied Mechanics and Engineering

View full text Add to dashboard Cite

The conventional approach for the identification of the work hardening properties of a material by an indentation test usually relies on the force-displacement curve. However, finite element modeling of the indenter-specimen system is a complex task, and the unicity of the solution to the inverse problem of identifying material parameters using the force-displacement curve is not always guaranteed. Also, the precise measurement of the displacement of the indenter tip requires the determination of the indenter frame compliance and indenter tip deformation. To alleviate these problems, we propose in this work an approach based solely on the 3D indentation imprint shape measured after indenter withdrawal, rather than relying on the minimization of the pointwise discrepancy between the experimental and simulated indentation curve. We first build a mathematical "shape space" of indentation shapes in which a lower-dimensional manifold of imprints admissible according to a postulated material constitutive law is approximated. Then, we solve the inverse problem by using a series of predictor-corrector algorithms minimizing the distance between the estimated solution and the experimental imprint in this shape space. We finally apply the proposed approach to indentation tests using a spherical tip indenter on two different materials: a C100 steel specimen and a specimen of the AU4G (AA2017) aluminium alloy.

show abstract

“…It is found that for ideally sharp indenter, [6][7][8][9][10] an approximate one-to-one correspondence exists between the ratio of hardness to reduced Young's modulus and the ratio of elastic work to total work. A similar relationship for spherical indentation 11 with any definite ratio of indentation depth to spherical radius in the range of 0.05-0.5 has also been revealed.…”

Section: Introductionmentioning

confidence: 99%

New relationship between Young's modulus and nonideally sharp indentation parameters

Ong

Wong

2004

J. Mater. Res.

View full text Add to dashboard Cite

Both analysis and numerical calculations have been carried out to investigate the relationship between Young's modulus and nonideally sharp indentation parameters. The results confirm that there exists an approximate one-to-one correspondence between the ratio of nominal hardness/reduced Young's modulus (H n /E r ) and the ratio of elastic work/total work (W e /W) for any definite bluntness ratio (⌬h/h m ) of a nonideally sharp indenter. Based on this relationship, the Young's modulus of the indented material can be determined just from the values of H n , W e , and W, which are directly measurable quantities in an indentation test.

show abstract

Determination of elasto-plastic properties by instrumented sharp indentation: guidelines for property extraction

Cited by 204 publications

References 1 publication

Computational modeling of the forward and reverse problems in instrumented sharp indentation

Computational modeling of the forward and reverse problems in instrumented sharp indentation

Identification of material properties using indentation test and shape manifold learning approach

New relationship between Young's modulus and nonideally sharp indentation parameters

Contact Info

Product

Resources

About