Determination of Coulomb’s Friction Coefficient Directly from Cylinder Compression Tests

Duran, Deniz; Karadoğan, Celalettin

doi:10.5545/sv-jme.2015.3141

Cited by 11 publications

(6 citation statements)

References 27 publications

(25 reference statements)

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“…The relationship F versus h shows that the measured values of indentation test fits well with the FE data using the friction coefficient of μ = 0.20. The so-defined coefficient of the friction is aligned with Trzepieciński and Lemu [31] and slightly lower value as defined by Duran [32]. The limiting values of the diagram in Fig.…”

Section: Experimental Calibration Of Friction Coefficient μ Used In Fsupporting

confidence: 67%

Study of Influential Parameters of the Sphere Indentation Used for the Control Function of Material Properties in Forming Operations

Satošek

Valeš

Pepelnjak

2019

SV-JME

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The uncertainties of modern, adaptable sheet metal forming systems are classified into model errors and disturbances. To improve the control of production, disturbances in the forming process need to be reduced. For this purpose, a new data flow system was introduced. It connected the data flow of all influencing material parameters into the “material property control function”. To control on-line the forming production line and acquire necessary material data, an indentation test was implemented. The main parameters to follow in this test are pile-up or sink-in values after the embossing of the ball-shaped tool into the material where the innovative approach of fully anisotropic material description was used. To set-up an optimal indentation test, parametric studies were performed with material data of AW 5754-H22. Finite element simulations were used to evaluate the influences of indenter diameter, contact friction and forming history of used the material. Fully anisotropic material behaviour was considered. Novel to this approach were a) the linking of the linear correlation of pile-up with the indentation depth described by gradient k, and b) the linking of gradient k with different pre-strains by a new power function.

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Section: Experimental Calibration Of Friction Coefficient μ Used In Fsupporting

confidence: 67%

Study of Influential Parameters of the Sphere Indentation Used for the Control Function of Material Properties in Forming Operations

Satošek

Valeš

Pepelnjak

2019

SV-JME

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“…An obvious one is via comparison with outcomes from uniaxial testing. This can be done in tension and/or compression, although the latter does tend to have an element of uncertainty associated with the effects of interfacial friction [38][39][40][41][42][52][53][54] and comparisons with tensile test outcomes are more common. The easiest comparison to make is between the nominal stress-strain curves, with that for the tensile test being obtained directly and that from PIP testing via FEM simulation of the tensile test (using the inferred true stress-strain relationship and the sample dimensions used in the test-although these only affect the postnecking part of the plot).…”

Section: Cross-checking With Other Experimental Outcomesmentioning

confidence: 99%

“…There is information available in the literature about likely values of μ under different conditions. [38][39][40][41][42] Concerning indentation with a large sphere specifically, the surfaces of both indenter and sample are normally quite smooth and the value of μ is expected to be fairly low-probably somewhere in the approximate range of 0.1-0.2. In practice, the exact value does not have a very strong effect on outcomes, although neglect of friction (μ ¼ 0) will lead to interfacial sliding occurring throughout the test, which is rather unrealistic.…”

Section: Constitutive Laws and Fem Model Formulationmentioning

confidence: 99%

Profilometry‐Based Inverse Finite Element Method Indentation Plastometry

Clyne

Campbell²,

Burley³

et al. 2021

Adv Eng Mater

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This is a review of the current state‐of‐the‐art regarding a particular approach to extraction of the (quasistatic) stress–strain relationship of a metallic sample from an indentation experiment. It is based on the application of a relatively high load (kN range) to the sample via a large spherical indenter (≈1 mm radius), followed by measurement of the indent profile. This profile is then used as the target outcome for inverse finite element method (FEM) modeling of the test, aimed at converging on the best fit set of parameter values in a constitutive plasticity law (true stress–true strain relationship). This can then be used to simulate any specified loading configuration, including a conventional tensile test. Commercial products are now available in which the indentation, profilometry, and convergence operations are all automated and completed within a few minutes. The review covers the various conceptual and practical issues involved in implementation and optimization of these procedures, including both those related to the measurement system (experimental and FEM simulation) and those associated with the sample (such as anisotropy, inhomogeneities, and residual stresses). An attempt is made to convey an impression of the expected levels of reliability and also the scope for obtaining insights that are not readily obtainable using other types of test.

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“…In such cases, the assumption of uniform stress and strain fields is again invalid, although it is again possible to take its effect into account via FEM modeling. [53][54][55][56][57][58][59][60] Unlike necking during tensile testing, friction during compression affects the outcome from the start. On the other hand, its effects may be relatively small, whereas necking always has a strong effect on a plot of nominal stress against nominal strain.…”

Section: Uniaxial Testingmentioning

confidence: 99%

A Critical Appraisal of the Instrumented Indentation Technique and Profilometry‐Based Inverse Finite Element Method Indentation Plastometry for Obtaining Stress–Strain Curves

Campbell¹,

Zhang

Burley³

et al. 2021

Adv Eng Mater

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A comparison is presented between conventional tensile stress‐strain curves and those obtained via two methodologies based on (spherical) indentation. The first, termed Instrumented Indentation Technique (IIT), involves conversion of load‐displacement data to stress‐strain curves via analytical expressions. This has been done using loads below 1 N (“nano”) and in the kN range (“macro”). The other procedure, termed profilometry‐based indentation plastometry (PIP), is based on repeated finite element method (FEM) simulation, using the residual indent profile as the target outcome and obtaining the best fit set of parameter values in a constitutive stress‐strain law. This has been done on a macro scale only. The data from nano‐IIT tend to be very noisy and variable, whereas those from macro‐IIT are more reproducible and less noisy. With one of the two empirical formulations employed, the agreement of the macro‐IIT with experiment is close to being acceptable for the work hardening characteristics, although inferred values of the yield stress are in poor agreement with those from tensile testing. In contrast to this, the PIP procedure provides outcomes that are in close agreement with those from tensile testing, concerning both yield stress and work hardening. The causes of this are explored and discussed.

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Determination of Coulomb’s Friction Coefficient Directly from Cylinder Compression Tests

Cited by 11 publications

References 27 publications

Study of Influential Parameters of the Sphere Indentation Used for the Control Function of Material Properties in Forming Operations

Study of Influential Parameters of the Sphere Indentation Used for the Control Function of Material Properties in Forming Operations

Profilometry‐Based Inverse Finite Element Method Indentation Plastometry

A Critical Appraisal of the Instrumented Indentation Technique and Profilometry‐Based Inverse Finite Element Method Indentation Plastometry for Obtaining Stress–Strain Curves

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