Young’s Modulus of Polysilicon Thin Film Evaluated by Finite Element Analysis

2007 ◽  
Vol 353-358 ◽  
pp. 2227-2230
Author(s):  
Kazuto Tanaka ◽  
Kohji Minoshima ◽  
Takehiro Imoto

To analyze the effect of the crystal orientations and the grain size on the Young's modulus of thin polysilicon microelements, two-dimensional finite element models in plain strain condition were developed using a Voronoi structure. The number of grains in a model of a 10 μm square area was changed from 23 to 1200. The grain size and the crystal orientation of the film were analyzed by means of an electron back-scattering diffraction pattern (EBSP) method. The average grain size of the front surface of the thin film was about 0.69 μm, which is almost equal to the grain size of the Voronoi model having 300 grains. From the results of EBSP analysis, the specimen had no oriented structure. Therefore, random crystal orientation was given to each grain of the FEM models. When the number of grains increased, the Young's modulus converged on about 171 GPa and its scatter caused by the different sets of the random orientation was reduced. The Young's modulus obtained by the FEM analysis was larger than the value obtained by the tensile tests.

2006 ◽  
Vol 326-328 ◽  
pp. 219-222 ◽  
Author(s):  
Dong Cheon Baek ◽  
Soon Bok Lee

As a reliable tool to measure the Young’s modulus, nanoindention technique has been used widely recently. In this paper, nanoindetation technique was overviewed with its advantage and limitation and a new method was proposed to determine material properties of film, i.e. both Young’s modulus E and Poisson’s ratio ν from load-displacement curve of shallow-depth indentation using ‘inverse method’.


2018 ◽  
Vol 2018 ◽  
pp. 1-12
Author(s):  
J. Jakubowicz ◽  
M. Sopata ◽  
G. Adamek ◽  
P. Siwak ◽  
T. Kachlicki

The nanocrystalline tantalum-ceramic composites were made using mechanical alloying followed by pulse plasma sintering (PPS). The tantalum acts as a matrix, to which the ceramic reinforced phase in the concentration of 5, 10, 20, and 40 wt.% was introduced. Oxides (Y2O3 and ZrO2) and carbides (TaC) were used as the ceramic phase. The mechanical alloying results in the formation of nanocrystalline grains. The subsequent hot pressing in the mode of PPS results in the consolidation of powders and formation of bulk nanocomposites. All the bulk composites have the average grain size from 40 nm to 100 nm, whereas, for comparison, the bulk nanocrystalline pure tantalum has the average grain size of approximately 170 nm. The ceramic phase refines the grain size in the Ta nanocomposites. The mechanical properties were studied using the nanoindentation tests. The nanocomposites exhibit uniform load-displacement curves indicating good integrity and homogeneity of the samples. Out of the investigated components, the Ta-10 wt.% TaC one has the highest hardness and a very high Young’s modulus (1398 HV and 336 GPa, resp.). For the Ta-oxide composites, Ta-20 wt.% Y2O3 has the highest mechanical properties (1165 HV hardness and 231 GPa Young’s modulus).


2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Chunlai Tian ◽  
Pengfei Duan

Composite has been widely used in various fields due to its advanced performance. To reveal the relation between the mechanical properties of the composite and that of each individual component, finite element analysis (FEA) has usually been adopted. In this study, in order to predict the mechanical properties of hard coating on a soft polymer, the response of this coating system during nanoindentation was modelled. Various models, such as a viscoelastic model and fitting model, were adopted to analyse the indentation response of this coating system. By varying the substrate properties (i.e., Young’s modulus, viscoelasticity, and Poisson’s ratio), Young’s modulus, energy loss, and the viscoelastic model of the coating system were analysed, and how the mechanical properties of the substrate will affect the indentation response of the coating system was discussed.


2015 ◽  
Vol 52 (7) ◽  
pp. 961-970 ◽  
Author(s):  
Christopher T. Senseney ◽  
Jacob Grasmick ◽  
Michael A. Mooney

A dynamic finite element (FE) model of lightweight deflectometer (LWD) loading on a two-layer soil system, validated with an analytical solution and experimental data, is presented. Peak dynamic FE vertical deflections can be substantially different (almost always smaller) than FE static deflections. The numerically simulated measurement depth of the LWD center sensor is found to be 2–2.5 times the plate diameter, deeper than other experimental studies. Using the FE model, we conduct a sensitivity analysis of peak vertical deflections to the top layer Young’s modulus and underlying Young’s modulus of two-layer systems. Peak deflections from the center sensor are found to be more sensitive to the top layer Young’s modulus while peak deflections at radial offsets are found to be more sensitive to the underlying layer Young’s modulus. Sensitivities of layer moduli to FE deflections offer guidance in selecting weighting factors for the inverse solver in an LWD back-calculation procedure.


2006 ◽  
Vol 321-323 ◽  
pp. 278-281
Author(s):  
Wen Quan Cui ◽  
Ye Yeon Won ◽  
Myong Hyun Baek ◽  
Kwang Kyun Kim

The purpose of this study was to investigate the contribution of the microstructural properties of trabecular bone in predicting its elastic modulus in the intertrochanteric region. A total of 15 trabecular bone core specimens were obtained from the proximal femurs of patients undergoing total hip arthroplasty. The micro-computed tomography (micro-CT) was used to scan each specimen to obtain micro-morphology. Microstructural parameters were directly calculated using software. Micro-CT images were converted to micro-finite element model using meshing technique, and then micro-finite element analysis (FEA) was performed to assess the mechanical property (Young’s modulus) of trabecular bone. The results showed that the ability to explain this variance of Young’s modulus is improved by combining the structural indices with each other. It suggested that assessment of bone microarchitecture should be added as regards detection of osteoporosis and evaluation of the efficacy of drug treatments for osteoporosis.


2017 ◽  
Vol 139 (10) ◽  
Author(s):  
Andrew Shin ◽  
Lawrence Yoo ◽  
Joseph Park ◽  
Joseph L. Demer

Historical emphasis on increased intraocular pressure (IOP) in the pathogenesis of glaucoma has been challenged by the recognition that many patients lack abnormally elevated IOP. We employed finite element analysis (FEA) to infer contribution to optic neuropathy from tractional deformation of the optic nerve head (ONH) and lamina cribrosa (LC) by extraocular muscle (EOM) counterforce exerted when optic nerve (ON) redundancy becomes exhausted in adduction. We characterized assumed isotropic Young's modulus of fresh adult bovine ON, ON sheath, and peripapillary and peripheral sclera by tensile elongation in arbitrary orientations of five specimens of each tissue to failure under physiological temperature and humidity. Physical dimensions of the FEA were scaled to human histological and magnetic resonance imaging (MRI) data and used to predict stress and strain during adduction 6 deg beyond ON straightening at multiple levels of IOP. Young's modulus of ON sheath of 44.6 ± 5.6 MPa (standard error of mean) greatly exceeded that of ON at 5.2 ± 0.4 MPa, peripapillary sclera at 5.5 ± 0.8 MPa, and peripheral sclera at 14.0 ± 2.3 MPa. FEA indicated that adduction induced maximum stress and strain in the temporal ONH. In the temporal LC, the maximum stress was 180 kPa, and the maximum strain was ninefold larger than produced by IOP elevation to 45 mm Hg. The simulation suggests that ON sheath traction by adduction concentrates far greater mechanical stress and strain in the ONH region than does elevated IOP, supporting the novel concept that glaucomatous optic neuropathy may result at least partly from external traction on the ON, rather than exclusively on pressure on the ON exerted from within the eye.


2014 ◽  
Vol 64 ◽  
pp. 1-8 ◽  
Author(s):  
K. Zhuravleva ◽  
R. Müller ◽  
L. Schultz ◽  
J. Eckert ◽  
A. Gebert ◽  
...  

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