A Finite-Element-Based Study of the Load Distribution of a Heavily Loaded Spur Gear System With Effects of Transmission Shafts and Gear Blanks

2003 ◽  
Vol 125 (3) ◽  
pp. 625-631 ◽  
Author(s):  
Tian Yong-tao ◽  
Li Cong-xin ◽  
Tong Wei ◽  
Wu Chang-hua
Keyword(s):  
Finite Element ◽  
Load Distribution ◽  
Contact Region ◽  
Three Dimensional ◽  
Gear Wheel ◽  
Spur Gear ◽  
Gear System ◽  
Fe Model ◽  
Tooth Width ◽  
Quadratic Programming Method

Spur gears were typically analyzed in the past using two-dimensional (2-D) Finite Element (FE) models. This is not adequate in many cases. A three-dimensional (3-D) FE model of a spur gear system, which accommodates all the gear teeth, the gear bodies, and the two transmission shafts, is developed in this paper using a sub-structuring method. The load between pinion and gear wheel is delivered by elastic frictional contact. The contact problem is solved according to the FE parametric quadratic programming method. The paper presents the shape of the contact region as well as the load distribution along the tooth width and profile. The results show that the transmission shafts have significant effects on the contact conditions including load distribution, contact region, and load deviation. The proposed method also applies to other types of gearing.

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.

Contact Stress Evaluation of Involute Gear Pairs, Including the Effects of Friction and Helix Angle

2015 ◽  
Vol 137 (4) ◽  
Author(s):  
Santosh S. Patil ◽  
Saravanan Karuppanan ◽  
Ivana Atanasovska
Keyword(s):  
Finite Element ◽  
Friction Factor ◽  
Contact Stress ◽  
Three Dimensional ◽  
Helix Angle ◽  
Spur Gear ◽  
Helical Gear ◽  
Contact Stresses ◽  
Fe Model ◽  
3D Finite Element Method

The aim of this technical brief is to provide a new viewpoint of friction factor for contact stress calculations of gears. The idea of friction factor has been coined, for the calculation of contact stresses along the tooth contact for different helical gear pairs. Friction factors were developed by evaluating contact stresses with and without friction for different gear pairs. In this paper, three-dimensional (3D) finite element method (FEM) and Lagrange multiplier algorithm have been used to evaluate the contact stresses. Initially, a spur gear finite element (FE) model was validated with the theoretical analysis under frictionless condition, which is based on Hertz's contact theory. Then, similar FE models were constructed for 5 deg, 15 deg, 25 deg, and 35 deg helical gear pairs. The contact stresses of these models were evaluated for different coefficients of friction. These results were employed for the development of friction factor.

Three-Dimensional Analyses of Spur Gear Bending Stresses by Global-Local Finite Element Technique

2013 ◽  
Vol 365-366 ◽  
pp. 309-313 ◽  
Author(s):  
Ya Zhou Xu ◽  
Zhi Xue Wu ◽  
Shu Ai Tian ◽  
Ya Jun Hua
Keyword(s):  
Load Distribution ◽  
Gear Tooth ◽  
Three Dimensional ◽  
Spur Gear ◽  
Elastic Stresses ◽  
Distribution Form ◽  
Face Width ◽  
Tooth Width ◽  
Bending Stresses ◽  
Element Technique

Three-dimensional elastic stresses developed in the root fillet of spur gear tooth due to uniform or non-uniform load distribution are analyzed in detail using global-local technique. Results indicate that root stresses distribute always non-uniformly along tooth width, and the maximum critical root stress (CRS) and its position depend on the face width and load distribution form. The maximum CRS is always higher than the corresponding value obtained under plane assumption and the value on the free surface. So, it is dangerous to use the CRSs calculated in practical gear designs. This research provides knowledge of root stresses for engineer to guard against gear failure and to design for increased loading.

A Simple Approach for Determining the Holding Capacity of Torpedo Anchors Embedded in Cohesive Soils

2013 ◽  
Author(s):  
Cristiano S. de Aguiar ◽  
José Renato M. de Sousa ◽  
Luís V. S. Sagrilo ◽  
Gilberto B. Ellwanger ◽  
Elisabeth C. Porto
Keyword(s):  
Finite Element ◽  
Contact Region ◽  
Low Cost ◽  
Three Dimensional ◽  
Computational Effort ◽  
Simple Approach ◽  
Cohesive Soils ◽  
Fe Model ◽  
Inclined Loads ◽  
Surrounding Soil

Torpedo anchors have been used in various offshore applications especially due to its low cost installation and the ability to withstand high inclined loads. This anchor consists of a shaft in which flukes are welded in order to increase the soil-anchor contact region and, consequently, its holding capacity. Since this anchor presents a singular geometry, different from a regular cylindrical anchor/pile, the computation of the holding capacity of a torpedo anchor is not straightforward. In a previously presented work, the holding capacities of typical torpedo anchors were assessed with a finite element (FE) model in which both the anchor and the surrounding soil are represented with three-dimensional finite elements. However, this FE model demands a significant computational effort and, consequently, simpler approaches would be desirable in order to design these anchors. Relying on the FE model and a parametric study, this paper presents simple formulae to predict the holding capacities of torpedo anchors embedded into cohesive soils. These formulae are employed to predict the holding capacities of two different torpedo anchors, which are compared to those estimated with the FE model. Results agreed very well indicating that this simpler approach may be employed to quickly evaluate the holding capacities of these anchors.

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.

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.

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.

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