Zimmer Frame Use and Back Strain Analysis Using a Finite Element Model

2020 ◽  
Author(s):  
Sydney Harwood ◽  
Parisa Saboori
Keyword(s):  
Finite Element ◽  
Chronic Back Pain ◽  
Large Strain ◽  
Strain Analysis ◽  
Element Model ◽  
Erector Spinae ◽  
Aging Effects ◽  
Element Analysis ◽  
Frame Design ◽  
Lower Back

Abstract The current walking frame used by the elderly has several design issues that can cause long term health problems. One of these problems is the development of chronic pain in the lower back. The design of the current walking frame promotes a slumping posture that causes a curvature in the spine. This curvature results in a large strain in the lower back muscles, specifically the erector spinae. The goal of this research was to design a new walking frame that would be more structurally sound and more practical to use than the present walking frame design. In this study, two literature searches were performed. The first was to explore how aging effects the ability to walk. The second involved studying all of the existing walking devices and analyzing their design strengths and weaknesses. As a result of these studies, three new preliminary walking frame designs were considered that promoted better posture when used, and provided more support than does the present walking frame design. These new designs were considered and tested using a finite element analysis (FEA). From this FEA, it was determined that the new walking frame design resulted in less stress in the lower back than does the present walking frame design. It was therefore concluded that the new model has the potential to decease chronic back pain.

Stress and Strain Analysis of Composite Gas Cylinder Based on ABAQUS

2012 ◽  
Vol 557-559 ◽  
pp. 300-303
Author(s):  
Cheng Hong Duan ◽  
Xiang Peng Luo ◽  
Nan Zhang
Keyword(s):  
Finite Element ◽  
Strain Analysis ◽  
Element Model ◽  
Stress And Strain ◽  
Analysis Method ◽  
Element Analysis ◽  
Finite Element Software ◽  
Finite Element Analysis Method ◽  
Gas Cylinder ◽  
Gas Cylinders

In this paper, a finite element model of a composite gas cylinder was established by ABAQUS finite element software, with consideration that both heads were helically wound and their wound angle and wound thickness varied with different parallel circle radius. Stress of the composite gas cylinder and PEEQ of its liner under different working conditions after autofrettage treatment were studied, the stress distribution was assessed by the DOT CFFC standard and the effective range of autofrettage treatment was confirmed. This finite element analysis method may be referable to the design and inspection of composite gas cylinders.

Stress Strain Analysis of Steel Specimens Not Wholly Quenched

2011 ◽  
Vol 261-263 ◽  
pp. 702-706
Author(s):  
Rui Jie Wang ◽  
He Ming Cheng ◽  
Bao Dong Shao ◽  
Jian Yun Li
Keyword(s):  
Finite Element ◽  
Fatigue Crack Initiation ◽  
Strain Analysis ◽  
Element Model ◽  
Cyclic Strength ◽  
Work Piece ◽  
Stress Strain ◽  
Element Analysis ◽  
Quenched Steel ◽  
Crack Initiation Life

A finite element model of not wholly quenched steel fatigue specimen is established. Hardness value of some distance to work piece surface are assumed different and cyclic strength coefficients of different zones are different, both is assumed to be proportional to hardness value. Elasto-plastic finite element analysis was carried out for this model. According to the stress-strain distribution on transverse section, the effect of not wholly quenched on fatigue crack initiation life is analyzed.

Finite Element Analysis of Laminating Press Frame

2011 ◽  
Vol 201-203 ◽  
pp. 44-48
Author(s):  
Xin Zhou Zhang ◽  
Shang Bin Wang ◽  
Kai Wu ◽  
Yu Sun
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Boundary Conditions ◽  
Structural Characteristics ◽  
Complex Structure ◽  
Element Model ◽  
Stress And Strain ◽  
Element Analysis ◽  
Frame Design ◽  
Different Parts

The structural characteristics of a laminating press were analyzed, and the corresponding finite element model was built with some essential simplification. By structural analysis, the distributions of stress and strain were obtained, based on which the rationality of the frame design can be verified. According to the complex structure and loading conditions of the laminating press, four analytical schemes with different models and boundary conditions were adopted, then the results of different analytical schemes were compared, and the causes resulting in the calculation differences were analyzed. The result shows that in analyzing different parts of the laminating press frame, different models and boundary conditions were required.

Large strain analysis of soft biological membranes: Formulation and finite element analysis

1996 ◽  
Vol 132 (1-2) ◽  
pp. 45-61 ◽  
Author(s):  
Gerhard A. Holzapfel ◽  
Robert Eberlein ◽  
Peter Wriggers ◽  
Hans W. Weizsäcker
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Large Strain ◽  
Biological Membranes ◽  
Strain Analysis ◽  
Element Analysis

Multi-Condition Analysis and Optimization of Sprayer Frame

2016 ◽  
Vol 835 ◽  
pp. 632-638
Author(s):  
Zhi Hong Wang ◽  
Jin Biao Wu ◽  
Jia Wu Liu
Keyword(s):  
Finite Element ◽  
Constant Velocity ◽  
3D Model ◽  
Maximum Stress ◽  
Element Model ◽  
Element Analysis ◽  
Frame Design ◽  
Emergency Braking ◽  
Stress And Deformation ◽  
Distribution Of Stress

A high clearance self-propelled sprayer was designed, and a 3D model of sprayer frame was built with CATIA. Its finite element model was built by using Hypermesh, and it was imported to ABAQUS for finite element analysis. The analysis researched the stress and deformation of frame under four typical conditions of constant-velocity, torsion, emergency braking and emergency turning. The weak region of strength in the variable track mechanism was found, and a size optimization research was carried to the square pipe of the variable track mechanism. The result showed that the maximum stress of frame after optimization decreased obviously, and the distribution of stress became much more reasonable. The optimization ensured the reliability of the frame design.

Nonlinear Finite Element Analysis and Test of Lateral Loading for Two-Post ROPS

2009 ◽  
Vol 16-19 ◽  
pp. 866-870 ◽  
Author(s):  
Ji Xin Wang ◽  
Xun Yang ◽  
Xiang Jun Yu
Keyword(s):  
Finite Element ◽  
Large Strain ◽  
Shell Element ◽  
Deformation Mode ◽  
Element Model ◽  
Nonlinear Finite Element ◽  
Lateral Loading ◽  
Distribution Law ◽  
Element Analysis ◽  
Loading Case

According to the structural characteristic and the test requirement of tow-post ROPS, a nonlinear finite element model of ROPS based on large-strain shell element was established, and the influence of elastic-plastic deformation of ROPS was taken into consideration. Then the computer simulation of ROPS was performed in lateral loading case, which obtained the deformation mode and the distribution law of equivalent plastic stress of ROPS followed by the discussion of deformation mechanism of ROPS. The simulation results accorded with test results. This paper can provide theoretical basis for the structural design of two-post ROPS.

КОНСТРУКТИВНО-ТЕХНОЛОГІЧНІ ОСОБЛИВОСТІ ХВОСТО-ВИХ БАЛОК СІТЧАСТОГО ТИПУ З ПОЛІМЕРНИХ КОМПО-ЗИЦІЙНИХ МАТЕРІАЛІВ ВЕРТОЛЬОТІВ ТРАНСПОРТНОЇ КАТЕГОРІЇ

2020 ◽  
pp. 15-30
Author(s):  
А. Г. Гребеников ◽  
И. В. Малков ◽  
В. А. Урбанович ◽  
Н. И. Москаленко ◽  
Д. С. Колодийчик
Keyword(s):  
Finite Element ◽  
Strain State ◽  
Layer Structure ◽  
Metal Structure ◽  
Element Model ◽  
Stress Strain ◽  
Element Analysis ◽  
Mesh Structure ◽  
Stress Strain State ◽  
Mesh Structures

The analysis of the design and technological features of the tail boom (ТB) of a helicopter made of polymer composite materials (PCM) is carried out.Three structural and technological concepts are distinguished - semi-monocoque (reinforced metal structure), monocoque (three-layer structure) and mesh-type structure. The high weight and economic efficiency of mesh structures is shown, which allows them to be used in aerospace engineering. The physicomechanical characteristics of the network structures are estimated and their uniqueness is shown. The use of mesh structures can reduce the weight of the product by a factor of two or more.The stress-strain state (SSS) of the proposed tail boom design is determined. The analysis of methods for calculating the characteristics of the total SSS of conical mesh shells is carried out. The design of the tail boom is presented, the design diagram of the tail boom of the transport category rotorcraft is developed. A finite element model was created using the Siemens NX 7.5 system. The calculation of the stress-strain state (SSS) of the HC of the helicopter was carried out on the basis of the developed structural scheme using the Advanced Simulation module of the Siemens NX 7.5 system. The main zones of probable fatigue failure of tail booms are determined. Finite Element Analysis (FEA) provides a theoretical basis for design decisions.Shown is the effect of the type of technological process selected for the production of the tail boom on the strength of the HB structure. The stability of the characteristics of the PCM tail boom largely depends on the extent to which its design is suitable for the use of mechanized and automated production processes.A method for the manufacture of a helicopter tail boom from PCM by the automated winding method is proposed. A variant of computer modeling of the tail boom of a mesh structure made of PCM is shown.The automated winding technology can be recommended for implementation in the design of the composite tail boom of the Mi-2 and Mi-8 helicopters.

Delamination in the scoring and folding of paperboard

TAPPI Journal ◽  
2012 ◽  
Vol 11 (1) ◽  
pp. 61-66 ◽  
Author(s):  
DOEUNG D. CHOI ◽  
SERGIY A. LAVRYKOV ◽  
BANDARU V. RAMARAO
Keyword(s):  
Finite Element ◽  
Plane Deformation ◽  
Strain Analysis ◽  
Local Strain ◽  
Uniaxial Stress ◽  
Material Model ◽  
Element Model ◽  
Plastic Behavior ◽  
Stress Strain ◽  
Strain Fields

Delamination between layers occurs during the creasing and subsequent folding of paperboard. Delamination is necessary to provide some stiffness properties, but excessive or uncontrolled delamination can weaken the fold, and therefore needs to be controlled. An understanding of the mechanics of delamination is predicated upon the availability of reliable and properly calibrated simulation tools to predict experimental observations. This paper describes a finite element simulation of paper mechanics applied to the scoring and folding of multi-ply carton board. Our goal was to provide an understanding of the mechanics of these operations and the proper models of elastic and plastic behavior of the material that enable us to simulate the deformation and delamination behavior. Our material model accounted for plasticity and sheet anisotropy in the in-plane and z-direction (ZD) dimensions. We used different ZD stress-strain curves during loading and unloading. Material parameters for in-plane deformation were obtained by fitting uniaxial stress-strain data to Ramberg-Osgood plasticity models and the ZD deformation was modeled using a modified power law. Two-dimensional strain fields resulting from loading board typical of a scoring operation were calculated. The strain field was symmetric in the initial stages, but increasing deformation led to asymmetry and heterogeneity. These regions were precursors to delamination and failure. Delamination of the layers occurred in regions of significant shear strain and resulted primarily from the development of large plastic strains. The model predictions were confirmed by experimental observation of the local strain fields using visual microscopy and linear image strain analysis. The finite element model predicted sheet delamination matching the patterns and effects that were observed in experiments.

Torsional Analysis of a Steel Cord-Rubber Tire Belt Structure

1996 ◽  
Vol 24 (4) ◽  
pp. 339-348 ◽  
Author(s):  
R. M. V. Pidaparti
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Composite Structures ◽  
Three Dimensional ◽  
Element Model ◽  
Torsional Stiffness ◽  
Element Analysis ◽  
Rubber Belt ◽  
Steel Cord ◽  
Torsional Analysis

Abstract A three-dimensional (3D) beam finite element model was developed to investigate the torsional stiffness of a twisted steel-reinforced cord-rubber belt structure. The present 3D beam element takes into account the coupled extension, bending, and twisting deformations characteristic of the complex behavior of cord-rubber composite structures. The extension-twisting coupling due to the twisted nature of the cords was also considered in the finite element model. The results of torsional stiffness obtained from the finite element analysis for twisted cords and the two-ply steel cord-rubber belt structure are compared to the experimental data and other alternate solutions available in the literature. The effects of cord orientation, anisotropy, and rubber core surrounding the twisted cords on the torsional stiffness properties are presented and discussed.

Finite Element Analysis of Nonuniformity of Tires with Imperfections5

2007 ◽  
Vol 35 (3) ◽  
pp. 226-238 ◽  
Author(s):  
K. M. Jeong ◽  
K. W. Kim ◽  
H. G. Beom ◽  
J. U. Park
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Radial Force ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Dimensional Finite Element ◽  
Force Variation ◽  
Three Dimensional Finite Element

Abstract The effects of variations in stiffness and geometry on the nonuniformity of tires are investigated by using the finite element analysis. In order to evaluate tire uniformity, a three-dimensional finite element model of the tire with imperfections is developed. This paper considers how imperfections, such as variations in stiffness or geometry and run-out, contribute to detrimental effects on tire nonuniformity. It is found that the radial force variation of a tire with imperfections depends strongly on the geometrical variations of the tire.

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