Nonconformal mesh-based finite element strategy for 3D textile composites

2016 ◽  
Vol 51 (16) ◽  
pp. 2315-2330 ◽  
Author(s):  
B Wucher ◽  
S Hallström ◽  
D Dumas ◽  
T Pardoen ◽  
C Bailly ◽  
...  
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Material Properties ◽  
Three Dimensional ◽  
Textile Composites ◽  
Thermoelastic Properties ◽  
Material Interfaces ◽  
Local Correction ◽  
Finite Element Procedure ◽  
Woven Reinforcement

A finite element procedure is developed for the computation of the thermoelastic properties of textile composites with complex and compact two- and three-dimensional woven reinforcement architectures. The purpose of the method is to provide estimates of the properties of the composite with minimum geometrical modeling effort. The software TexGen is used to model simplified representations of complex textiles. This results in severe yarn penetrations, which prevent conventional meshing. A non-conformal meshing strategy is adopted, where the mesh is refined at material interfaces. Penetrations are mitigated by using an original local correction of the material properties of the yarns to account for the true fiber content. The method is compared to more sophisticated textile modeling approaches and successfully assessed towards experimental data selected from the literature.

scholarly journals A Three-Dimensional Inverse Finite Element Analysis of the Heel Pad

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
Snehal Chokhandre ◽  
Jason P. Halloran ◽  
Antonie J. van den Bogert ◽  
Ahmet Erdemir
Keyword(s):  
Experimental Data ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Material Properties ◽  
Three Dimensional ◽  
Element Analysis ◽  
Heel Pad ◽  
Tool Force ◽  
Specific Material ◽  
Inverse Finite Element Analysis

Quantification of plantar tissue behavior of the heel pad is essential in developing computational models for predictive analysis of preventive treatment options such as footwear for patients with diabetes. Simulation based studies in the past have generally adopted heel pad properties from the literature, in return using heel-specific geometry with material properties of a different heel. In exceptional cases, patient-specific material characterization was performed with simplified two-dimensional models, without further evaluation of a heel-specific response under different loading conditions. The aim of this study was to conduct an inverse finite element analysis of the heel in order to calculate heel-specific material properties in situ. Multidimensional experimental data available from a previous cadaver study by Erdemir et al. (“An Elaborate Data Set Characterizing the Mechanical Response of the Foot,” ASME J. Biomech. Eng., 131(9), pp. 094502) was used for model development, optimization, and evaluation of material properties. A specimen-specific three-dimensional finite element representation was developed. Heel pad material properties were determined using inverse finite element analysis by fitting the model behavior to the experimental data. Compression dominant loading, applied using a spherical indenter, was used for optimization of the material properties. The optimized material properties were evaluated through simulations representative of a combined loading scenario (compression and anterior-posterior shear) with a spherical indenter and also of a compression dominant loading applied using an elevated platform. Optimized heel pad material coefficients were 0.001084 MPa (μ), 9.780 (α) (with an effective Poisson’s ratio (ν) of 0.475), for a first-order nearly incompressible Ogden material model. The model predicted structural response of the heel pad was in good agreement for both the optimization (<1.05% maximum tool force, 0.9% maximum tool displacement) and validation cases (6.5% maximum tool force, 15% maximum tool displacement). The inverse analysis successfully predicted the material properties for the given specimen-specific heel pad using the experimental data for the specimen. The modeling framework and results can be used for accurate predictions of the three-dimensional interaction of the heel pad with its surroundings.

scholarly journals On the Design of a Biodegradable POC-HA Polymeric Cardiovascular Stent

2012 ◽  
Author(s):  
Joonas Ponkala ◽  
Mohsin Rizwan ◽  
Panos S. Shiakolas
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Material Properties ◽  
Three Dimensional ◽  
Polymeric Composite ◽  
Coronary Stent ◽  
Element Analysis ◽  
Material Models ◽  
Solid Models ◽  
Biodegradable Stents

The current state of the art in coronary stent technology, tubular structures used to keep the lumen open, is mainly populated by metallic stents coated with certain drugs to increase biocompatibility, even though experimental biodegradable stents have appeared in the horizon. Biodegradable polymeric stent design necessitates accurate characterization of time dependent polymer material properties and mechanical behavior for analysis and optimization. This manuscript presents the process for evaluating material properties for biodegradable biocompatible polymeric composite poly(diol citrate) hydroxyapatite (POC-HA), approaches for identifying material models and three dimensional solid models for finite element analysis and fabrication of a stent. The developed material models were utilized in a nonlinear finite element analysis to evaluate the suitability of the POC-HA material for coronary stent application. In addition, the advantages of using femtosecond laser machining to fabricate the POC-HA stent are discussed showing a machined stent. The methodology presented with additional steps can be applied in the development of a biocompatible and biodegradable polymeric stents.

An adaptive p-FEM for three-dimensional concrete aggregate models

2020 ◽  
Vol 11 (01) ◽  
pp. 2050004
Author(s):  
Ruiqi Guo ◽  
Yingxiong Xiao
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Three Dimensional ◽  
Poor Quality ◽  
Numerical Results ◽  
Concrete Aggregate ◽  
Material Interfaces ◽  
Reinforced Composite ◽  
Text Version ◽  
Particle Reinforced Composite

Numerical simulation for concrete aggregate models (CAMs) with different shape aggregates usually requires high accuracy and convergence near the material interfaces. But high memory usage will be needed for those traditional finite element methods such as the method by using mesh refinement throughout the domain. Thus, an adaptive [Formula: see text]-version finite element method ([Formula: see text]-FEM) is proposed in this paper for the solution of 3D CAM problems, and meanwhile the resulting adaptive computational algorithm and post-processing program are presented. We firstly focused two typical 3D weak discontinuity problems on the influence of different convergence criterions for the computational results of each point on the interface in order to verify the efficiency and convergence of the resulting [Formula: see text]-FEM, and then this method is successfully applied to the numerical simulation of CAMs with different shape aggregates. In addition, an efficient hybrid realization method which combines ANSYS and Hypermesh software is also presented in order to quickly establish the geometric models of 3D CAMs. The numerical results have been shown that the proposed [Formula: see text]-FEM can efficiently solve the concrete-like particle-reinforced composite problems and more accurate numerical results can be obtained under the case of fewer elements used in simulation of CAMs, even there being some elements with poor quality.

A Novel Three-Dimensional Finite Element Model to Simulate Third Body Effects on Fretting Wear of Hertzian Point Contact in Partial Slip

2020 ◽  
Vol 143 (4) ◽  
Author(s):  
Arman Ahmadi ◽  
Farshid Sadeghi
Keyword(s):  
Finite Element ◽  
Material Properties ◽  
Three Dimensional ◽  
Point Contact ◽  
Fretting Wear ◽  
Partial Slip ◽  
Wear Particles ◽  
Third Body ◽  
Stick Slip ◽  
The Third

Abstract In this investigation, a finite element (FE) model was developed to study the third body effects on the fretting wear of Hertzian contacts in the partial slip regime. An FE three-dimensional Hertzian point contact model operating in the presence of spherical third bodies was developed. Both first bodies and third bodies were modeled as elastic–plastic materials. The effect of the third body particles on contact stresses and stick-slip behavior was investigated. The influence of the number of third body particles and material properties including modulus of elasticity, hardening modulus, and yield strength were analyzed. Fretting loops in the presence and absence of wear particles were compared, and the relation between the number of cycles and the hardening process was evaluated. The results indicated that by increasing the number of particles in contact, more load was carried by the wear particles which affect the wear-rate of the material. In addition, due to the high plastic deformation of the debris, the wear particles deformed and took a platelet shape. Local stick-slip behavior over the third body particles was also observed. The results of having wear debris with different material properties than the first bodies indicated that harder wear particles have a higher contact pressure and lower slip at the location of particles which affects the wear-rate.

Analytical evaluation of thermally induced residual stresses in ground components

2003 ◽  
Vol 217 (5) ◽  
pp. 471-482 ◽  
Author(s):  
D G Walsh ◽  
A A Torrance ◽  
J Tiberg
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Critical Temperature ◽  
Yield Strength ◽  
Residual Stresses ◽  
Material Properties ◽  
Analytical Evaluation ◽  
Simple Method ◽  
Thermally Induced

Although thermally induced tensile residual stresses have been known to occur in ground components, it has not been possible to predict the critical temperature at which these stresses begin to manifest themselves in the workpiece. In this paper, a model of the formation of thermally induced tensile residual stresses is proposed and a simple method of calculating the critical temperature above which tensile residual stresses occur is developed. The analysis makes use of dimensional methods to characterize the critical temperature. In addition, a formula characterizing the yield strength as a function of temperature was developed. The model was then validated using finite element techniques and some experimental data. The analysis reveals that it is possible to determine the critical temperature above which tensile residual stresses will be manifested based on readily available material properties. A case study illustrates the application of the technique.

scholarly journals Modeling and Stochastic Model Updating of Bolt-Jointed Structure

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Ming Zhan ◽  
Qintao Guo ◽  
Lin Yue ◽  
Baoqiang Zhang
Keyword(s):  
Finite Element ◽  
High Resolution ◽  
Material Properties ◽  
Model Updating ◽  
Computational Cost ◽  
Three Dimensional ◽  
Element Model ◽  
Joint Interface ◽  
Unknown Parameters ◽  
Updating Procedure

Bolt-jointed structure is widely used in engineering fields. The dynamic characteristics of bolt-jointed structure are complex, and there is a variety of uncertainties in the jointed structure. In this study, modeling and updating of a typical bolt-jointed structure are investigated. In modeling terms, three-dimensional brick elements are used to represent the substructures, and thin-layer elements with virtual material properties are employed to represent the joint interface. Modal tests and experimental modal analysis of substructures and built-up structure are performed. A hierarchical model updating strategy based on Bayesian inference is applied to identify the unknown parameters in the substructures model and those in the overall model. Radial basis function (RBF) models are used as surrogates of time-consuming finite element model with high resolution to avoid the enormous computational cost. The results indicate that the updated model can reproduce modal frequencies used in updating and can predict those not used in the updating procedure.

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