Mechanical Properties Identification of Viscoelastic/Hyperplastic Materials Using Haptic Device Based Experimental Setup

2011 ◽  
Vol 486 ◽  
pp. 115-118
Author(s):  
Alican Tabakci ◽  
Erhan Ilhan Konukseven

Mechanical behavior simulation of viscoelastic materials is a difficult task. In order to obtain accurate simulations, material model should be well chosen and hyperelastic characteristics of the viscoelastic materials should also be incorporated in the model. Once the material model is selected the coefficients can be identified with the help of mechanical tests/experiments. The main goal of this study is to optimize material model’s coefficients by using the designed indenter test setup results and inverse finite element modeling. Indenter test setup was designed by using a haptic device, force sensor and data acquisition card to test the mechanical properties of the viscoelastic/hyperelastic materials. Inverse finite element modeling method is used in order to model the materials according to their material characteristics. The model obtained from the analysis was optimized by using the data obtained from indenter tests. The conformity of the chosen model and the tested materials is shown by inverse finite element modeling and the material model coefficients are proved to be identified correctly.

1996 ◽  
Vol 444 ◽  
Author(s):  
S. M. Myers ◽  
D. M. Follstaedt ◽  
J. A. Knapp ◽  
T. R. Christenson

AbstractDual ion implantation of titanium and carbon was shown to produce an amorphous surface layer in annealed bulk nickel, in electroformed Ni, and in electroformed Ni7 5Fe 2 5. Diamond-tip nanoindentation coupled with finite-element modeling quantified the elastic and plastic mechanical properties of the implanted region. The amorphized matrix, with a thickness of about 100 nm, has a yield stress of approximately 6 GP and an intrinsic hardness near 16 GPa, exceeding by an order of magnitude the corresponding values for annealed bulk Ni. Implications for micro-electromechanical systems are discussed.


1996 ◽  
Vol 438 ◽  
Author(s):  
J. A. Knapp ◽  
D. M. Follstaedt ◽  
J. C. Barbour ◽  
S. M. Myers ◽  
J. W. Ager ◽  
...  

AbstractWe present a methodology based on finite-element modeling of nanoindentation data to extract reliable and accurate mechanical properties from thin, hard films and surface-modified layers on softer substrates. The method deduces the yield stress, Young's modulus, and hardness from indentations as deep as 50% of the layer thickness.


2018 ◽  
Vol 773 ◽  
pp. 3-9 ◽  
Author(s):  
Ilya A. Morozov ◽  
Anton Y. Beliaev ◽  
Roman I. Izyumov

Stiff coating on the phase-separated soft polyurethane substrate under the compression deformation is investigated by the finite element modeling (FEM). External strain leads to the wrinkling of layer surface, which is characterized by a set of wavelengths and amplitudes. The influence of the thickness and stiffness of the layer, elastic modulus of the substrate on the structural-mechanical properties of the deformed surface is studied. The results of the model are in good accordance with the experiment (plasma immersion ion impanation of nitrogen ions into the polyurethane substrate) and allowed to estimate the modulus of the coating and the deformation of the surface.


1999 ◽  
Vol 593 ◽  
Author(s):  
P.J. Wolff ◽  
B.N. Lucas ◽  
E.G. Herbert

ABSTRACTA commonly used technique to compute mechanical properties from indentation tests is the Oliver and Pharr method. Using dimensional analysis and finite element modeling, this paper investigates errors when the Oliver and Pharr method is used to compute thin film properties.


2004 ◽  
Vol 19 (1) ◽  
pp. 218-227 ◽  
Author(s):  
J.A. Knapp ◽  
D.M. Follstaedt

Thin-film mechanical properties can be measured using nanoindentation combined with detailed finite element modeling. This technique was used for a study of very fine grained Ni films, formed using pulsed-laser deposition on fused silica, sapphire, and Ni substrates. The grain sizes in the films were characterized by electron microscopy, and the mechanical properties were determined by ultra-low load indentation, analyzed using finite element modeling to separate the mechanical properties of the thin layers from those of the substrates. Some Ni films were deposited at high temperature or annealed after deposition to enlarge the grain sizes. The observed hardnesses and grain sizes in these thin Ni films are consistent with the empirical Hall–Petch relationship for grain sizes ranging from a few micrometers to as small as 10 nm, suggesting that deformation occurs preferentially by dislocation movement even in such nanometer-size grains.


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