Identification of local constitutive model from micro-indentation testing

2011 ◽  
pp. 177-182 ◽  
Author(s):  
Y Marco ◽  
V Le Saux ◽  
G Bles ◽  
S Calloch ◽  
P Charrier
Keyword(s):  
Constitutive Model ◽  
Indentation Testing ◽  
Micro Indentation

Compressive Properties of Mouse Articular Cartilage Determined in a Novel Micro-Indentation Test Method and Biphasic Finite Element Model

2006 ◽  
Vol 128 (5) ◽  
pp. 766-771 ◽  
Author(s):  
Li Cao ◽  
Inchan Youn ◽  
Farshid Guilak ◽  
Lori A Setton
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Articular Cartilage ◽  
Indentation Test ◽  
Small Animal ◽  
Element Model ◽  
Indentation Testing ◽  
Compressive Properties ◽  
Biphasic Finite Element ◽  
Micro Indentation

The mechanical properties of articular cartilage serve as important measures of tissue function or degeneration, and are known to change significantly with osteoarthritis. Interest in small animal and mouse models of osteoarthritis has increased as studies reveal the importance of genetic background in determining predisposition to osteoarthritis. While indentation testing provides a method of determining cartilage mechanical properties in situ, it has been of limited value in studying mouse joints due to the relatively small size of the joint and thickness of the cartilage layer. In this study, we developed a micro-indentation testing system to determine the compressive and biphasic mechanical properties of cartilage in the small joints of the mouse. A nonlinear optimization program employing a genetic algorithm for parameter estimation, combined with a biphasic finite element model of the micro-indentation test, was developed to obtain the biphasic, compressive material properties of articular cartilage. The creep response and material properties of lateral tibial plateau cartilage were obtained for wild-type mouse knee joints, by the micro-indentation testing and optimization algorithm. The newly developed genetic algorithm was found to be efficient and accurate when used with the finite element simulations for nonlinear optimization to the experimental creep data. The biphasic mechanical properties of mouse cartilage in compression (average values: Young’s modulus, 2.0MPa; Poisson’s ratio, 0.20; and hydraulic permeability, 1.1×10−16m4∕N‐s) were found to be of similar orders of magnitude as previous findings for other animal cartilages, including human, bovine, rat, and rabbit and demonstrate the utility of the new test methods. This study provides the first available data for biphasic compressive properties in mouse cartilage and suggests a promising method for detecting altered cartilage mechanics in small animal models of osteoarthritis.

Test and Simulation of Indentation and Scratch on ZnS

2013 ◽  
Vol 770 ◽  
pp. 50-53
Author(s):  
Guang Yao ◽  
Bing Guo ◽  
Chang Hao Wu
Keyword(s):  
Mechanical Properties ◽  
Constitutive Model ◽  
Process Parameters ◽  
Indentation Test ◽  
Scratch Test ◽  
Nanoindentation Test ◽  
Removal Mechanism ◽  
Precision Grinding ◽  
Ultra Precision ◽  
Micro Indentation

This paper discusses the grinding performance of ZnS. Its the base for ultra-precision grinding to master the mechanical properties and removal mechanism of ZnS which is an infrared material. This study determined the hardnessfracture toughness and critical grinding depth by micro-indentation test; Based on the result of nanoindentation test, constitutive model of ZnS was established and simulation of indentation and scratch were completed. Grinding removal mechanism and effect of process parameters on scratch result were explored by scratch test. It was found that test was consistent with simulation.

Sign in / Sign up

Export Citation Format

Share Document