Strength Analysis of Syntactic Foams Using a Three-Dimensional Continuum Damage Finite Element Model

2015 ◽  
Vol 82 (2) ◽  
Author(s):  
Yejie Shan ◽  
Guodong Nian ◽  
Qiang Xu ◽  
Weiming Tao ◽  
Shaoxing Qu
Keyword(s):  
Finite Element ◽  
Tensile Strength ◽  
Volume Fraction ◽  
Three Dimensional ◽  
Syntactic Foam ◽  
Interfacial Strength ◽  
Strength Analysis ◽  
Failure Behavior ◽  
Fe Model ◽  
Syntactic Foams

The failure behavior of the syntactic foams is investigated based on a three-dimensional (3D) micromechanical finite element (FE) model, by varying the volume fraction, the wall thickness of the hollow particles, and the interfacial strength. The maximum principal stress criterion is adopted to determine the state (damaged or undamaged) for both interface and matrix. Material property degradation is used to describe the mechanical behavior of those damaged elements. The current model can reasonably predict the tensile strength of the syntactic foams with high volume fractions (40%–60%). The failure mechanism of the syntactic foam under uniaxial tension is captured by analyzing the stress–strain curves and the contours of damaging evolution process. Results from the quantitative simulations demonstrate that the tensile strength of the syntactic foam can be improved effectively by enhancing the interfacial strength.

Finite Element Study of the Cutting Mechanics of the Three Dimensional Rock Turning Process

2015 ◽  
Author(s):  
Demeng Che ◽  
Jacob Smith ◽  
Kornel F. Ehmann
Keyword(s):  
Finite Element ◽  
Oil And Gas ◽  
Three Dimensional ◽  
Polycrystalline Diamond ◽  
Close Correlation ◽  
Experimental Results ◽  
Failure Behavior ◽  
Fe Model ◽  
Gas Drilling ◽  
Cutting Mechanics

The unceasing improvements of polycrystalline diamond compact (PDC) cutters have pushed the limits of tool life and cutting efficiency in the oil and gas drilling industry. However, the still limited understanding of the cutting mechanics involved in rock cutting/drilling processes leads to unsatisfactory performance in the drilling of hard/abrasive rock formations. The Finite Element Method (FEM) holds the promise to advance the in-depth understanding of the interactions between rock and cutters. This paper presents a finite element (FE) model of three-dimensional face turning of rock representing one of the most frequent testing methods in the PDC cutter industry. The pressure-dependent Drucker-Prager plastic model with a plastic damage law was utilized to describe the elastic-plastic failure behavior of rock. A newly developed face turning testbed was introduced and utilized to provide experimental results for the calibration and validation of the formulated FE model. Force responses were compared between simulations and experiments. The relationship between process parameters and force responses and the mechanics of the process were discussed and a close correlation between numerical and experimental results was shown.

Finite Element Analysis on Drilling of Unidirectional Carbon Fiber Reinforced Plastic (CFRP)

2013 ◽  
Vol 455 ◽  
pp. 228-231 ◽  
Author(s):  
Yan Li He ◽  
Guo Peng Zhang ◽  
Jun Peng Xue
Keyword(s):  
Finite Element ◽  
Carbon Fiber ◽  
Thrust Force ◽  
Three Dimensional ◽  
Failure Behavior ◽  
Drilling Process ◽  
Fe Model ◽  
Fiber Reinforced ◽  
Element Analysis ◽  
Carbon Fiber Reinforced

Various kinds of damage may occur during the drilling of carbon fiber reinforced polymer composite (CFRP). To review the mechanism of CFRP drilling, a three-dimensional macro-mechanical finite element (FE) model was constructed for CFRP drilling based on FE software tool Abaqus. The workpiece was modeled as equivalent homogenous anisotropic material (EHAM) with elastic-failure behavior. Three-dimensional Hashin criterion was used to predict the material failure. The material was implemented in user subroutine VUMAT. The drilling process was analyzed and the thrust force with respect to cutting conditions was evaluated. The simulation shows that thrust force increase with feed rates while decrease with spindle speed, as agrees with experiment.

The Effect of Trabecular Bone on the Mechanical Response of Human Mandible with Implant

2014 ◽  
Vol 695 ◽  
pp. 588-591
Author(s):  
Khairul Salleh Basaruddin ◽  
Ruslizam Daud
Keyword(s):  
Computed Tomography ◽  
Finite Element ◽  
Trabecular Bone ◽  
Static Analysis ◽  
Load Distribution ◽  
Mechanical Response ◽  
Three Dimensional ◽  
Fe Model ◽  
Micro Computed Tomography ◽  
Bone Specimen

This study aims to investigate the influence of trabecular bone in human mandible bone on the mechanical response under implant load. Three dimensional voxel finite element (FE) model of mandible bone was reconstructed from micro-computed tomography (CT) images that were captured from bone specimen. Two FE models were developed where the first consists of cortical bone, trabecular bone and implants, and trabecular bone part was excluded in the second model. A static analysis was conducted on both models using commercial software Voxelcon. The results suggest that trabecular bone contributed to the strength of human mandible bone and to the effectiveness of load distribution under implant load.

scholarly journals Evaluation of the Effects of the Chincup Appliance on the Craniofacial Structures by the Finite Element Analysis

2017 ◽  
Vol 7 ◽  
pp. 219-223
Author(s):  
Beril Demir Karamanli ◽  
Hülya Kılıçoğlu ◽  
Armagan Fatih Karamanli
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Fe Model ◽  
Analysis Method ◽  
Class Iii ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Clinical Changes

Aims The aim of this study is to evaluate the effects of the chincup appliance used in the treatment of Class III malocclusions, not only on the mandible or temporomandibular joint (TMJ) but also on all the craniofacial structures. Materials and Methods Chincup simulation was performed on a three-dimensional finite element (FE) model. 1000 g (500 g per side) force was applied in the direction of chin-condyle head. Nonlinear FE analysis was used as the numerical analysis method. Results By the application of chincup, stresses were distributed not only on TMJ or mandible but also on the circummaxillary sutures and other craniofacial structures. Conclusions Clinical changes obtained by chincup treatment in Class III malocclusions are not limited by only mandible. It was seen that also further structures were affected.

An Analytical and Experimental Study of Strength and Failure Behavior of Plain Weave Composites

1998 ◽  
Vol 32 (1) ◽  
pp. 2-30 ◽  
Author(s):  
Makoto Ito ◽  
Tsu-Wei Chou
Keyword(s):  
Volume Fraction ◽  
Random Phase ◽  
Three Dimensional ◽  
Tensile Tests ◽  
Packing Fraction ◽  
Failure Behavior ◽  
Fiber Volume ◽  
Laminate Composites ◽  
Plain Weave ◽  
Geometrical Characteristics

This paper analyzes the strengxth and failure behavior of plain weave composites. First, the geometrical characteristics of yarn shape, laminate stacking configuration, fiber volume fraction, and yarn packing fraction are investigated using three-dimensional geometrical models. Based on the geometrical characteristics, iso-strain approach is developed to predict elastic properties, stress distributions, and strengths under tensile loading. The laminate stacking configuration and fabric waviness ratio have significant influence on the composite failure behavior. Specimens of iso-phase, out-of-phase and random-phase laminate composites are prepared. The mathematical models developed are evaluated by microscopic observation and tensile tests.

A Biomechanical Model of Lumbar Spine

2000 ◽  
Author(s):  
Subramanya Uppala ◽  
Robert X. Gao ◽  
Scott Cowan ◽  
K. Francis Lee
Keyword(s):  
Finite Element ◽  
Lumbar Spine ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Biomechanical Model ◽  
Element Model ◽  
Fe Model ◽  
Flexion Extension ◽  
Cortical Shell ◽  
Three Dimensional Finite Element

Abstract The strength and stability of the lumbar spine are determined not only by the bone and muscles, but also by the visco-elastic structures and the interplay between the different components of the spine, such as ligaments, capsules, annulus fibrosis, and articular cartilage. In this paper we present a non-linear three-dimensional Finite Element model of the lumbar spine. Specifically, a three-dimensional FE model of the L4-5 one-motion segment/2 vertebrae was developed. The cortical shell and the cancellous bone of the vertebral body were modeled as 3D isoparametric eight-nodal elements. Finite element models of spinal injuries with fixation devices are also developed. The deformations across the different sections of the spine are observed under the application of axial compression, flexion/extension, and lateral bending. The developed FE models provided input to both the fixture design and experimental studies.

Analysis of a Balanced Breech System for the M1A1 Main Gun System Using Finite Element Techniques

1994 ◽  
Author(s):  
David A. Hopkins ◽  
Stephen A. Wilkerson
Keyword(s):  
Finite Element ◽  
Kinetic Energy ◽  
Three Dimensional ◽  
System Change ◽  
Sine Wave ◽  
Fe Model ◽  
Firing Cycle ◽  
Entire System ◽  
Tube Shape ◽  
Series Of Experiments

Abstract A series of experiments were recently conducted in an attempt to reduce the dynamic motions of the M256 gun system during firing. Data collected during these experiments included the motion of the gun tube and breech mechanism for both the standard (unbalanced) configuration and a modified system in which mass was added such that the breech center of gravity (CG) was coincident with the gun tube centerline. The results indicated a noticeable change in the dynamic motions between these two configurations. Prior experiments indicated that the unbalanced breech drops several tenths of a millimeter during the firing cycle. Also, the gun tube whipping motion, which is induced by the powder pressure couple, vibrates the gun in a similar fashion regardless of ammunition type. Furthermore, the gun tube shape at shot exit always resembles a distorted sine wave. This behavior was noted for both heat and kinetic energy (KE) munitions in previous unbalanced breech tests conducted with the M256 gun. However, when the breech is balanced, the dynamics of the entire system change in both shape and magnitude of displacement. This report attempts to explain the results of the tests performed. This was accomplished using a three-dimensional (3-D), transient, finite element (FE) model of the entire system, which included breech, gun tube, trunnion mount, recoil, and projectile. Results from these calculations provide an explanation of the observed behavior of the system. Insight acquired about the nature of the system’s behavior was then used to propose several simple improvements to the M256 gun system which can be applied to gun systems in general. Implementation of these changes should decrease the shot-to-shot variability associated with gun accuracy.

scholarly journals A robust 3D finite element model for concrete columns confined by FRCM system

2019 ◽  
Vol 281 ◽  
pp. 01006 ◽  
Author(s):  
Majid M.A. Kadhim ◽  
Mohammed J Altaee ◽  
Ali Hadi Adheem ◽  
Akram R. Jawdhari
Keyword(s):  
Finite Element ◽  
Cement Mortar ◽  
Three Dimensional ◽  
Concrete Columns ◽  
Element Model ◽  
Fe Model ◽  
3D Finite Element ◽  
Composite Failure ◽  
Global Buckling ◽  
Fibre Reinforced Polymer

Fibre reinforced cementitious matric (FRCM) is a recent application of fibre reinforced polymer (FRP) reinforcement, developed to overcome several limitations associated with the use of organic adhesive [e.g. epoxies] in FRPs. It consists of two dimensional FRP mesh saturated with a cement mortar, which is inorganic in nature and compatible with concrete and masonry substrates. In this study, a robust three-dimensional (3D) finite element (FE) model has been developed to study the behaviour of slender reinforced concrete columns confined by FRCM jackets, and loaded concentrically and eccentrically. The model accounts for material nonlinearities in column core and cement mortar, composite failure of FRP mesh, and global buckling. The model response was validated against several laboratory tests from literature, comparing the ultimate load, load-lateral deflection and failure mode. Maximum divergence between numerical and experimental results was 12%. Following the validation, the model will be used later in a comprehensive parametric analysis to gain a profound knowledge of the strengthening system, and examine the effects of several factors expected to influence the behaviour of confined member.

A finite element model to study the effect of porosity location on the elastic modulus of a cantilever beam

2019 ◽  
Vol 43 (4) ◽  
pp. 443-453
Author(s):  
Stephen M. Handrigan ◽  
Sam Nakhla
Keyword(s):  
Finite Element ◽  
Elastic Modulus ◽  
Focused Ion Beam ◽  
Mechanical Response ◽  
Ion Beam ◽  
Three Dimensional ◽  
Beam Theory ◽  
Element Model ◽  
Fe Model ◽  
Three Dimensional Finite Element

An investigation to determine the effect of porosity concentration and location on elastic modulus is performed. Due to advancements in testing methods, the manufacturing and testing of microbeams to obtain mechanical response is possible through the use of focused ion beam technology. Meanwhile, rigorous analysis is required to enable accurate extraction of the elastic modulus from test data. First, a one-dimensional investigation with beam theory, Euler–Bernoulli and Timoshenko, was performed to estimate the modulus based on load-deflection curve. Second, a three-dimensional finite element (FE) model in Abaqus was developed to identify the effect of porosity concentration. Furthermore, the current work provided an accurate procedure to enable accurate extraction of the elastic modulus from load-deflection data. The use of macromodels such as beam theory and three-dimensional FE model enabled enhanced understanding of the effect of porosity on modulus.

Finite Element Analysis of the Nut-Supports Subassembly Based on ANSYS

2012 ◽  
Vol 215-216 ◽  
pp. 847-850
Author(s):  
Shou Jun Wang ◽  
Xing Xiong ◽  
Hong Jie Wang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Reference Data ◽  
Three Dimensional ◽  
Design Parameters ◽  
Weak Links ◽  
Fe Model ◽  
Element Analysis ◽  
Design And Optimization ◽  
Wave Maker

In the condition of alternating impact ,the nut-supports subassembly is analyzed according to uncertainty of design parameters. Firstly, a three-dimensional (3-D) finite element (FE) model of the nut-supports subassembly is built and is meshed,and the constraints and loads are imposed.Secondly,the model of nut-supports was assembled using the software ANSYS to understand the stress distribution and various parts of the deformation of the nut-supports and its weak links in the harmonic forces.Finally,socket head cap screw has not enough pre-load in the condition of alternating impact and will be simplified.It is analyzed and checked whether it is cut or not; which provides the reference data for design and optimization of the wave maker.

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