Thermomechanical Finite Element Analysis of Impact-Induced Magnetic Erasures in Magnetic Storage Thin Film Media

2007 ◽  
Author(s):  
Ning Yu ◽  
Andreas A. Polycarpou ◽  
Jorge V. Hanchi
Keyword(s):  
Finite Element ◽  
Hard Disk Drives ◽  
Three Dimensional ◽  
Thermal Response ◽  
Rotating Disk ◽  
Oblique Impact ◽  
Magnetic Storage ◽  
The Finite Element Method ◽  
Element Analysis ◽  
The Impact

Oblique impact of a slider with a rotating disk in hard disk drives was analyzed using the finite element method. A three dimensional, thermomechanical, impact model was developed to study the mechanical and thermal response during the impact of a spherical slider corner with the disk. The model was validated by comparing finite element results with analytical solutions for homogeneous glass disk under simple conditions. Impact penetration, stress and incurred flash temperature were obtained for various normal impact velocities.

Towards Predicting Relative Belt Edge Endurance With the Finite Element Method

1990 ◽  
Vol 18 (4) ◽  
pp. 216-235 ◽  
Author(s):  
J. De Eskinazi ◽  
K. Ishihara ◽  
H. Volk ◽  
T. C. Warholic
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Three Dimensional ◽  
The Finite Element Method ◽  
Shear Deformations ◽  
Element Analysis ◽  
Vertical Loading ◽  
Predicted Values ◽  
Element Method

Abstract The paper describes the intention of the authors to determine whether it is possible to predict relative belt edge endurance for radial passenger car tires using the finite element method. Three groups of tires with different belt edge configurations were tested on a fleet test in an attempt to validate predictions from the finite element results. A two-dimensional, axisymmetric finite element analysis was first used to determine if the results from such an analysis, with emphasis on the shear deformations between the belts, could be used to predict a relative ranking for belt edge endurance. It is shown that such an analysis can lead to erroneous conclusions. A three-dimensional analysis in which tires are modeled under free rotation and static vertical loading was performed next. This approach resulted in an improvement in the quality of the correlations. The differences in the predicted values of various stress analysis parameters for the three belt edge configurations are studied and their implication on predicting belt edge endurance is discussed.

scholarly journals New Design Procedure of Transtibial ProsthesisBed Stump Using Topological Optimization Method

Symmetry ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 1837 ◽  
Author(s):  
Martin Sotola ◽  
David Stareczek ◽  
David Rybansky ◽  
Jiri Prokop ◽  
Pavel Marsalek
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Design Procedure ◽  
Optimization Method ◽  
Topological Optimization ◽  
Element Analysis ◽  
Current Application ◽  
Transtibial Prosthesis ◽  
Walking Biomechanics ◽  
The Impact

This paper presents a new design procedure for production of a transtibial prosthesis bed stump by three-dimensional (3D) printing with topological optimization. The suggested procedure combines the medical perspective with finite element analysis and facilitates regaining the symmetry in patients with transtibial prosthesis, which leads to life improvement. The particular focus of the study is the weight reduction of the lower part of the bed stump, while taking into account its stiffness and load-bearing capacity. The first part of the work deals with the analysis of the subject geometry of the bed stump, which is usually oversized in terms of the weight and stiffness that are necessary for the current application. In the second part, an analysis of walking biomechanics with a focus on the impact and rebound phases is presented. Based on the obtained information, a spatial model of the lower part of the bed stump is proposed in the third phase, in which the finite element method is described. In the fourth part, the topological optimization method is used for reducing the structure weight. In the last part, the results of the designed model are analyzed. Finally, the recommendations for the settings of the method are presented. The work is based on the practical industry requirements, and the obtained results will be reflected in the design of new types of transtibial prosthesis.

Finite-element analysis of multi-body contacts for pile driving using a hydraulic pile hammer

2011 ◽  
Vol 225 (5) ◽  
pp. 1153-1161 ◽  
Author(s):  
Y Guo ◽  
J P Hu ◽  
L Y Zhang
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Test Point ◽  
Pile Driving ◽  
Penalty Function Method ◽  
Three Dimensional Model ◽  
Element Analysis ◽  
Material Choice ◽  
Multi Body ◽  
The Impact

This article treats the pile driving as multi-body dynamic contacts. By using the penalty function method and three-dimensional model of finite-element method, the dynamic process of pile driving is acquired and a method for choosing the cushion material of the hydraulic pile hammer to improve driving efficiency is proposed. The process of pile driving in the real situation of an industrial experiment is simulated. The results of stress on test point are consistent with the test point. By analysing the stress distributed along the direction of pile radius and pile axis, the rule of the stress distribution on the pile is concluded. The rule for cushion material choice is obtained by comparing the influence for the impact stress with different elastic modulus ratio of the hammer cushion to the pile and the pile cushion to the pile.

scholarly journals New Analytical Model Used in Finite Element Analysis of Solids Mechanics

Mathematics ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1401 ◽  
Author(s):  
Sorin Vlase ◽  
Adrian Eracle Nicolescu ◽  
Marin Marin
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Equations Of Motion ◽  
Classical Mechanics ◽  
Three Dimensional ◽  
Elastic Solid ◽  
The Finite Element Method ◽  
Governing Equations ◽  
Element Analysis ◽  
Elastic Multibody System

In classical mechanics, determining the governing equations of motion using finite element analysis (FEA) of an elastic multibody system (MBS) leads to a system of second order differential equations. To integrate this, it must be transformed into a system of first-order equations. However, this can also be achieved directly and naturally if Hamilton’s equations are used. The paper presents this useful alternative formalism used in conjunction with the finite element method for MBSs. The motion equations in the very general case of a three-dimensional motion of an elastic solid are obtained. To illustrate the method, two examples are presented. A comparison between the integration times in the two cases presents another possible advantage of applying this method.

Influence of temperature and strain rate on the longitudinal compressive crashworthiness of 3D braided composite tubes and finite element analysis

2016 ◽  
Vol 26 (7) ◽  
pp. 1003-1027 ◽  
Author(s):  
Xianyan Wu ◽  
Qian Zhang ◽  
Bohong Gu ◽  
Baozhong Sun
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Strain Rate ◽  
Coupling Effect ◽  
Three Dimensional ◽  
Composite Tubes ◽  
Element Analysis ◽  
Impact Compression ◽  
Mechanical Coupling ◽  
The Impact

This article reports the longitudinal compressive crashworthiness of three-dimensional four-step circular braided carbon/epoxy composite tubes at temperatures of 23, −50, and −100℃ under strain rate ranging from 340 to 760/s both experimentally and finite element analysis. The experimental results showed that the compression strength, stiffness, and specific energy absorption increased with the decrease in temperature and with the increase in strain rate. It also showed that, the compressive damage morphologies were sensitive to the change in temperature and strain rate. A coupled thermal-mechanical numerical analysis was conducted to find the thermo/mechanical coupling effect on the compressive crashworthiness of the three-dimensional composite tube. The temperature distributions in the braided preform and the resin during the impact compression were also calculated through finite element analysis. From the finite element analysis results, the inelastic heat generation was seen to be more in the preform than the matrix and its distribution and accumulation led to the damage progress along the loading direction.

Finite-element analysis of axi-symmetric rotors

1969 ◽  
Vol 4 (3) ◽  
pp. 163-168
Author(s):  
H Stordahl ◽  
H Christensen
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Three Dimensional ◽  
Two Dimensional ◽  
The Finite Element Method ◽  
Element Analysis ◽  
Engineering Problems ◽  
Symmetric Rotor ◽  
Practical Engineering ◽  
Element Method

The finite-element method (1) (2)∗ is increasingly used in the stress analysis of mechanical-engineering problems. It is the purpose of this paper to described how the finite-element method can be used as an effective tool in the design of rotors. Up to the present time this method has mainly been used in the analysis of two-dimensional problems. However, a special class of three-dimensional problems, namely axi-symmetric rotors, can be treated as a nearly two-dimensional problem. This paper summarizes the development of the finite-element method as applied to the analysis of the axi-symmetric rotor. A computer programme is then briefly described, and the application of the method to the solution of three examples taken from practical engineering experience are presented.

DESIGN STRATEGY OF THREE-DIMENSIONAL PRINTED CAGES TO REDUCE IMPACT-INDUCED DEBRIS ALONG THE LOAD-TRANSFERRING PATH

2021 ◽  
pp. 2050021
Author(s):  
Shang-Chih Lin ◽  
Yu-Pao Hsu ◽  
Ching-Hsiao Yu ◽  
Chun-Ming Chen ◽  
Po-Quang Chen
Keyword(s):  
Finite Element ◽  
Cellular Structure ◽  
Three Dimensional ◽  
Peak Stress ◽  
Transforaminal Lumbar Interbody Fusion ◽  
Design Strategy ◽  
Cellular Structures ◽  
The Finite Element Method ◽  
3D Printed ◽  
The Impact

Peri-implant debris certainly lead to osteolysis, necrosis, pseudotumor formation, tissue granulation, fibrous capsule contractions, and even implant failure. For the three-dimensional (3D) printed cage, impaction during cage insertion is one of the most potential sources of fracture debris. A finite-element study was carried out to reduce the impact-induced debris of the 3D-printed cage. This study focused on the design strategy of solid and cellular structures along the load-transferring path. Using the finite-element method, the cellular structure of the transforaminal lumbar interbody fusion (TLIF) cage was systematically modified in the following four variations: a noncellular cage (NC), a fully cellular (FC) cage, a solid cage with a cellular structure in the middle concave (MC) zone, and a strengthened cage (SC) in the MC zone. Three comparison indices were considered: the stresses at the cage-instrument interfaces, in the MC zone, and along the specific load-transferring path. The NC and FC were the least and most highly stressed variations at the cage-instrument interfaces and in the MC zone, respectively. Along the entirely load-transferring path, the FC was still the most highly stressed variation. It showed a higher risk of stress fracture for the FC cage. For the MC and SC, the MC zone was consistently more stressed than the directly impacted zone. The further strengthened design of the SC had a lower peak stress (approximately 29.2%) in the MC zone compared with the MC. Prior to 3D printing, the load-transferring path from the cage-instrument interfaces to the cage-tissue interfaces should be determined. The cage-instrument interfaces should be printed as a solid structure to avoid impact-induced fracture. The other stress-concentrated zones should be cautiously designed to optimize the coexistence strategy of the solid and cellular structures.

A Finite Element Analysis of the Navier-Stokes Equations Applied to High Speed Thin Film Lubrication

1987 ◽  
Vol 109 (1) ◽  
pp. 71-76 ◽  
Author(s):  
J. O. Medwell ◽  
D. T. Gethin ◽  
C. Taylor
Keyword(s):  
Finite Element ◽  
High Speed ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Navier Stokes ◽  
The Finite Element Method ◽  
Thin Film Lubrication ◽  
Element Analysis ◽  
Navier Stokes Equations ◽  
Film Lubrication

The performance of a cylindrical bore bearing fed by two axial grooves orthogonal to the load line is analyzed by solving the Navier-Stokes equations using the finite element method. This produces detailed information about the three-dimensional velocity and pressure field within the hydrodynamic film. It is also shown that the method may be applied to long bearing geometries where recirculatory flows occur and in which the governing equations are elliptic. As expected the analysis confirms that lubricant inertia does not affect bearing performance significantly.

Comparison of Stress Distribution in Surrounding Bone during Insertion of Dental Implants on Four Implant Threads under the Effect of an Impact: A Finite Element Study

2022 ◽  
Vol 54 ◽  
pp. 89-101
Author(s):  
Noureddine Djebbar ◽  
Abdessamed Bachiri ◽  
Benali Boutabout
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Load Transfer ◽  
Three Dimensional ◽  
Primary Stability ◽  
Implant Design ◽  
Element Analysis ◽  
Three Dimensional Finite Element ◽  
The Impact ◽  
Surrounding Bone

The design of an implant thread plays a fundamental role in the osseointegration process, particularly in low-density bone. It has been postulated that design features that maximize the surface area available for contact may improve mechanical anchorage and stability in cancellous bone. The primary stability of a dental implant is determined by the mechanical engagement between the implant and bone at the time of implant insertion. The contact area of implant-bone interfaces and the concentrated stresses on the marginal bones are principal concerns of implant designers. Numerous factors influence load transfer at the bone-implant interface, for example, the type of loading, surface structure, amount of surrounding bone, material properties of the implant and implant design. The purpose of this study was to investigate the effects of the impact two different projectile of implant threads on stress distribution in the jawbone using three-dimensional finite element analysis.

Stress Distribution of the Variable Dynamic Loading in the Dental Implant: A Three-Dimensional Finite Element Analysis

2017 ◽  
Vol 31 ◽  
pp. 44-52 ◽  
Author(s):  
Noureddine Djebbar ◽  
B. Serier ◽  
Bel Abbès Bachir Bouiadjra
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Dynamic Loading ◽  
Equivalent Stress ◽  
Three Dimensional ◽  
The Finite Element Method ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Chewing Activity

Stable osseointegration between implant threads and the surrounding marginal bone provides the mechanical base of an implant for daily chewing activity. The contact area of implant-bone interfaces and the concentrated stresses on the marginal bones are principal concerns of implant designers. In this work we numerically analyze by the finite element method the distribution of the equivalent stress and their level in the bone the most fragile element of the dental prosthesis. Each set of the model contained a crown, framework, abutment, implant and bone, subjected to variable dynamic loading according to time.

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