Determination of mechanical property of nanostructure using nano-macro equivalent mechanics method

2010 ◽  
Author(s):  
Chao-Jen Huang ◽  
Chung-Jung Wu ◽  
Hung-An Teng ◽  
Kuo-Ning Chiang
Keyword(s):  
Mechanical Property

Computational mechanical property determination of viscoelastic/plastic materials from nanoindentation creep test data

2009 ◽  
Vol 24 (3) ◽  
pp. 1245-1257 ◽  
Author(s):  
Jianjun Wang ◽  
Timothy C. Ovaert
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Finite Element ◽  
Test Data ◽  
Plastic Material ◽  
Test Method ◽  
Element Formulation ◽  
Unknown Parameters ◽  
Plastic Materials

Nanoindentation is a widely accepted test method for materials characterization. On account of the complexity of contact deformation behavior, design of parametric constitutive models and determination of the unknown parameters is challenging. To address the need for identification of mechanical properties of viscoelastic/plastic materials from nanoindentation data, a combined numerical finite element/optimization-based indentation modeling tool was developed, fully self-contained, and capable of running on a PC as a stand-alone executable program. The approach uses inverse engineering and formulates the material characterization task as an optimization problem. The model development consists of finite element formulation, viscoelastic/plastic material models, heuristic estimation to obtain initial solution boundaries, and a gradient-based optimization algorithm for fast convergence to extract mechanical properties from the test data. A four-parameter viscoelastic/plastic model is presented, then a simplified three-parameter model with more rapid convergence. The end result is a versatile tool for indentation simulation and mechanical property analysis.

Stiffness and strength properties of five paperboards and their moisture dependency

TAPPI Journal ◽  
2020 ◽  
Vol 19 (2) ◽  
pp. 71-85
Author(s):  
GUSTAV MARIN ◽  
MIKAEL NYGARDS ◽  
SOREN OSTLUND
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Shear Strength ◽  
Three Dimensional ◽  
Strength Properties ◽  
Bending Stiffness ◽  
Moisture Ratio ◽  
Machine Direction ◽  
Product Series

Five commercial multiply folding boxboards made on the same paperboard machine have been analyzed. The paperboards were from the same product series but had different grammage (235, 255, 270, 315, 340 g/m2) and different bending stiffness. The paperboards are normally used to make packages, and because the bending stiffness and grammage varies, the performance of the packages will differ. Finite element simulations can be used to predict these differences, but for this to occur, the stiffness and strength properties need to be deter-mined. For efficient determination of the three-dimensional properties in the machine direction (MD), cross direction (CD), and Z direction (ZD), it is proposed that the paperboard should be characterized using in-plane tension, ZD-tension, shear strength profiles, and two-point bending. The proposed setups have been used to determine stiff-ness and strength properties at different relative humidity (20,% 50%, 70%, and 90% RH), and the mechanical proper-ties have been evaluated as a function of moisture ratio. There was a linear relation between mechanical properties and moisture ratio for each paperboard. When the data was normalized with respect to the standard climate (50% RH) and plotted as a function of moisture ratio, it was shown that the normalized mechanical properties for all paperboards coincided along one single line and could therefore be expressed as a linear function of moisture ratio and two constants. Consequently, it is possible to obtain the mechanical properties of a paperboard by knowing the structural prop-erties for the preferred level of RH and the mechanical property for the standard climate (50% RH and 23°C).

scholarly journals Direct determination of graphene amount in electrochemical deposited Cu-based composite foil and its enhanced mechanical property

RSC Advances ◽  
2017 ◽  
Vol 7 (3) ◽  
pp. 1735-1742 ◽  
Author(s):  
Gongsheng Song ◽  
Zhongchi Wang ◽  
Youning Gong ◽  
Yanpeng Yang ◽  
Qiang Fu ◽  
...  
Keyword(s):  
Mechanical Property ◽  
Direct Determination

The amount of graphene (Gr) in a composite plays a key role in enhancing the performance of the composite.

Analytical and experimental resolutions in the duality of mechanical property extractions from instrumented indentation experiments: Comments on “On determination of material parameters from loading and unloading responses in nanoindentation with a single sharp indenter” by L. Wang and S.I. Rokhlin [J. Mater. Res. 21, 995, (2006)]

2007 ◽  
Vol 22 (5) ◽  
pp. 1138-1144 ◽  
Author(s):  
O. Casals ◽  
J. Alcalá
Keyword(s):  
Mechanical Property ◽  
Finite Element ◽  
Applied Load ◽  
Instrumented Indentation ◽  
Material Parameters ◽  
Acta Mater ◽  
Loading And Unloading ◽  
Computational Procedures ◽  
Contact Response

A controversial issue in mechanical property extractions from instrumented indentation applied load (P)–penetration depth (hs) curves concerns the possibility of finding more than one solid that essentially exhibits the same contact response. By recourse to finite element simulations of elastic-power law strain hardening solids, it was shown that for both the elasto-plastic and the fully plastic contact regimes it becomes possible to find an arbitrary number of solids whose P-hs curves are visually similar [L. Wang and S.I. Rokhlin, J. Mater. Res. 21, 995 (2006)]. Although this assertion supports prior findings [e.g., C.M. Cheng and Y.T. Cheng, J. Mater. Res. 14, 3493 (1999); K.K. Tho et al., Mater. Sci. Eng.A 390, 202 (2005); and J. Alkorta et al., J. Mater. Res.20, 432 (2005)], it apparently contradicts the work by Casals and Alcalá in which, through similar computational procedures and constitutive theory, it was shown that there can be “only” two solids with strictly the same P-hs curve [O. Casals and J. Alcalá, Acta Mater.53, 3545 (2005)]. The purpose of this comment is to reconcile the different views on the multiplicity of inferred properties that can be extracted from a single P-hs curve, as well as to address the issue of whether visually similar P-hs curves can be taken to be statistically identical both from analytical and experimental standpoints. Some considerations are also given regarding experiments performed with dual indenters.

Mechanical Property Determination of Thin Porous Low-kFilms by Twin-Transducer Laser Generated Surface Acoustic Waves

2004 ◽  
Vol 43 (2) ◽  
pp. 508-513 ◽  
Author(s):  
Xia Xiao ◽  
Nobuhiro Hata ◽  
Kazuhiro Yamada ◽  
Takamaro Kikkawa
Keyword(s):  
Mechanical Property ◽  
Acoustic Waves ◽  
Surface Acoustic Waves

Experimental Research on Dependencies of Mechanical Property of Elastomeric Isolator with Lower Hardness and Parameters Analysis

2012 ◽  
Vol 166-169 ◽  
pp. 2982-2994
Author(s):  
Chao Yong Shen ◽  
Yu Hong Ma ◽  
Xue Zhen Zhuang ◽  
Yang Yang Chen ◽  
Shi Bin Wang
Keyword(s):  
Mechanical Property ◽  
Shear Modulus ◽  
Bilinear Model ◽  
Rubber Bearing ◽  
Shear Property ◽  
Complete Study ◽  
Parameters Analysis ◽  
Elastomeric Isolator ◽  
Determination Of Parameters

LNR and LRB in which the value of shear modulus of inner rubber is 0.392MPa have been widely used in the practical isolation projects, although there are some test researches about dependency of shear property of them, but there is little complete study under high design compressive stress, such as 15MPa, and equations of dependency of shear property of them have seldom been found. In this paper, completely experiments about dependency of shear property of them have been done, and the fitted equations about various dependencies for LNR and LRB are given. Effect of size of rubber bearing on various dependencies is also studied. Formulas of determination of parameters in bilinear model of LRB are proposed, and have been testified well with FEA program.

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