Material Characterization and Modeling of Single-Wall Carbon Nanotube/Polyelectrolyte Multilayer Nanocomposites

2006 ◽  
Vol 73 (5) ◽  
pp. 737-744 ◽  
Author(s):  
Gang Huang ◽  
Bo Wang ◽  
Hongbing Lu ◽  
Arif Mamedov ◽  
Sachin Gupta
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Relaxation Modulus ◽  
Nanocomposite Films ◽  
Single Wall Carbon Nanotubes ◽  
Element Analysis ◽  
Single Wall Carbon ◽  
Volume Fractions

Strong single-wall carbon nanotubes (SWNTs) possess very high stiffness and strength. They have potential for use to tailor the material design to reach desired mechanical properties through SWNT nanocomposites. Layer-by-layer (LBL) assembly technique is an effective method to fabricate SWNT/polyelectrolyte nanocomposite films. To determine the relationship between the constituents of the SWNT/polymer nanocomposites made by LBL technique, a method has been developed to extend the recent work by Liu and Chen (Mech. Mater., 35, pp. 69–81, 2003) for the calculation of the effective Young’s modulus. The work by Liu and Chen on the mixture model is evaluated by finite element analysis of nanocomposites with SWNT volume fraction between 0% and 5%. An equivalent length coefficient is introduced and determined from finite element analysis. A formula is presented using this coefficient to determine the effective Young’s modulus. It is identified that the current work can be applied to SWNT loadings between 0% and 5%, while Liu and Chen’s approach is appropriate for relatively high SWNT volume fractions, close to 5%, but is not appropriate for relatively low SWNT volume fractions. The results obtained from this method are used to determine the effective Young’s modulus of SWNT/polyelectrolyte nanocomposite with 4.7% SWNT loading. The material properties are characterized using both nanoindentation and tensile tests. Nanoindentation results indicate that both the in-plane relaxation modulus and the through-thickness relaxation modulus of SWNT nanocomposites are very close to each other, despite the orientation preference of the SWNTs in the nanocomposites. The steady state in-plane Young’s relaxation modulus compares well with the tensile modulus, and measurement results are compared with Young’s modulus determined from the method presented.

scholarly journals Finite Element Analysis of the Nanomechanics of Hard Coatings on a Soft Polymer Substrate by a Spherical Indenter

2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Chunlai Tian ◽  
Pengfei Duan
Keyword(s):  
Mechanical Properties ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Viscoelastic Model ◽  
Coating System ◽  
Element Analysis ◽  
Soft Polymer ◽  
Indentation Response

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.

Contribution of Three-Dimensional Trabecular Bone Microstructure of the Proximal Femur to its Mechanical Properties as Assessed by Micro-Finite Element Analysis

2006 ◽  
Vol 321-323 ◽  
pp. 278-281
Author(s):  
Wen Quan Cui ◽  
Ye Yeon Won ◽  
Myong Hyun Baek ◽  
Kwang Kyun Kim
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Trabecular Bone ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Bone Microarchitecture ◽  
Element Model ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Element Analysis

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.

Determination of the Young’s modulus of porous ß-type Ti–40Nb by finite element analysis

2014 ◽  
Vol 64 ◽  
pp. 1-8 ◽  
Author(s):  
K. Zhuravleva ◽  
R. Müller ◽  
L. Schultz ◽  
J. Eckert ◽  
A. Gebert ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Element Analysis

Speed of sound reflects Young’s modulus as assessed by microstructural finite element analysis

Bone ◽  
2000 ◽  
Vol 26 (5) ◽  
pp. 519-524 ◽  
Author(s):  
J.P.W van den Bergh ◽  
G.H van Lenthe ◽  
A.R.M.M Hermus ◽  
F.H.M Corstens ◽  
A.G.H Smals ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Young’S Modulus ◽  
Speed Of Sound ◽  
Young's Modulus ◽  
Element Analysis

scholarly journals Numerical Evaluation of Spinal Stability after Posterior Spinal Fusion with Various Fixation Segments and Screw Types in Patients with Osteoporotic Thoracolumbar Burst Fracture Using Finite Element Analysis

2021 ◽  
Vol 11 (7) ◽  
pp. 3243
Author(s):  
Cheol-Jeong Kim ◽  
Seung Min Son ◽  
Sung Hoon Choi ◽  
Tae Sik Goh ◽  
Jung Sub Lee ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Spinal Fusion ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Burst Fracture ◽  
Posterior Spinal Fusion ◽  
Spinal Stability ◽  
Thoracolumbar Burst Fracture ◽  
Element Analysis

The aim of this study was to analyze the spinal stability and safety after posterior spinal fusion with various fixation segments and screw types in patients with an osteoporotic thoracolumbar burst fracture based on finite element analysis (FEA). To realize various osteoporotic vertebral fracture conditions on T12, seven cases of Young’s modulus, namely 0%, 1%, 5%, 10%, 25%, 50%, and 100% of the Young’s modulus, for vertebral bones under intact conditions were considered. Four types of fixation for thoracolumbar fracture on T12 (fixed with T11-L1, T10-T11-L1, T11-L1-L2, and T10-T11-L1-L2) were applied to the thoracolumbar fusion model. The following screw types were considered: pedicle screw (PS) and cortical screw (CS). Using FEA, four motions were performed on the fixed spine, and the stress applied to the screw, peri-implant bone (PIB), and intervertebral disc (IVD) and the range of motion (ROM) were calculated. The lowest ROM calculated corresponded to the T10-T11-L1-L2 model, while the closest to the intact situation was achieved in the T11-L1-L2 fixation model using PS. The lowest stress in the screw and PB was detected in the T10-T11-L1-L2 fixation model.

Further analysis of energy-based indentation relationship among Young’s modulus, nominal hardness, and indentation work

2010 ◽  
Vol 25 (6) ◽  
pp. 1131-1136 ◽  
Author(s):  
Dejun Ma ◽  
Chung Wo Ong
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Experimental Results ◽  
Poisson's Ratio ◽  
Element Analysis ◽  
Conical Indenter ◽  
Elastic Effect ◽  
Elastic Plastic

In our previous study, we modeled the indentation performed on an elastic–plastic solid with a rigid conical indenter by using finite element analysis, and established a relationship between a nominal hardness/reduced Young’s modulus (Hn/Er) and unloading work/total indentation work (We/Wt). The elasticity of the indenter was absorbed in Er ≡ 1/[(1 − ν2)/E + (1 − νi2)/Ei], where Ei and νi are the Young’s modulus and Poisson’s ratio of the indenter, and E and ν are those of the indented material. However, recalculation by directly introducing the elasticity of the indenter show that the use of Er alone cannot accurately reflect the combined elastic effect of the indenter and indented material, but the ratio η = [E/(1 − ν2)]/[Ei/(1 − νi2)] would influence the Hn/Er–We/Wt relationship. Thereby, we replaced Er with a combined Young’s modulus Ec ≡ 1/[(1 − ν2)/E + 1.32(1 − νi2)/Ei] = Er/[1 + 0.32η/(1 + η)], and found that the approximate Hn/Ec–We/Wt relationship is almost independent of selected η values over 0–0.3834, which can be used to give good estimates of E as verified by experimental results.

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