DYNAMIC CONTACT ANALYSIS OF TOTAL HIP PROSTHESIS DURING STUMBLING CYCLE

2014 ◽  
Vol 14 (03) ◽  
pp. 1450041 ◽  
Author(s):  
S. SHANKAR ◽  
M. MANIKANDAN
Keyword(s):  
Contact Pressure ◽  
Hip Prosthesis ◽  
Three Dimensional ◽  
Load Condition ◽  
Dynamic Contact ◽  
Element Model ◽  
Von Mises Stress ◽  
Metal Metal ◽  
Joint Contact ◽  
Von Mises

The estimation of the hip joint contact stresses and contact pressure distribution during stumbling activities is a critical task for selecting the best material pair in the hip prosthesis design. This paper utilizes a three-dimensional finite element model of acetabular component to analyze the dynamic stumbling activity using ANSYS®. The present study investigates the maximum von Mises stress, contact pressure and deformation developed for different combinations of materials under the stumbling load condition. The different combination of bearing couplings considered for the analysis are metal in contact with plastic, metal on metal, metal on ceramic, ceramic on plastic, ceramic on metal and ceramic on ceramic combinations. The results concluded that the Alumina femoral head paired with ultra-high molecular weight polyethylene (UHMWPE) cup reduces the maximum von Mises stress and maximum contact pressure developed between the interface regions when compared with other combinations. The obtained results are compared with the result of Hai-bo-Jiang et al., for available combinations, and higher correlation of 92% was found between the two results.

FE simulation of sealing ability for premium connection based on ISO 13679 CAL IV tests

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yihua Dou ◽  
Yufei Li ◽  
Yinping Cao ◽  
Yang Yu ◽  
Jiantao Zhang ◽  
...  
Keyword(s):  
Finite Element ◽  
Contact Pressure ◽  
Thermal Cycle ◽  
Three Dimensional ◽  
Element Model ◽  
Helix Angle ◽  
Von Mises Stress ◽  
Content Type ◽  
Von Mises ◽  
Three Dimensional Finite Element

PurposeTo maintain the well integrity, the strength and sealing ability of premium connection should be in the safe scope. ISO 13679 is widely used for evaluating the ability of tubing and casing connection all over the world. FE is adopted to simulate the ISO 13679 tests.Design/methodology/approachBecause of the disadvantage of experiment such as long period, high cost and high requirement on the facility, considering the convenience and universality of finite element method, as well as the contacting nonlinearity and material nonlinearity, three-dimensional finite element model of a certain type of premium connection is established with the consideration of helix angle. The loads exerted on the premium connection are the loads in series B test and thermal cycle test of ISO 13679. The distributions of Von Mises stress and contact pressure in various cases were studied.FindingsThe results showed that the bending load has a great influence on the distribution of Von Mises stress and contact pressure for premium connection. The Von Mises stress and contact pressures on the sealing surface are smaller on the tension side and greater on the compression side. With increasing axial compression load, the contact pressures on the tension side are too small, which may lead to sealing failure. The influence of temperature on the performance of premium connection cannot be ignored when choosing or designing premium connections. Both the Von Mises stress and contact pressure decrease slightly during a period of thermal cycle. Although the performance of the premium connection is good in a period of thermal cycle, its performance in a long period should be evaluated. Finite element simulation can effectively simulate the ISO 13679 test procedure and obtain the stress and contact pressure distribution. It can be used as a reference for evaluating the performance of premium connections.Originality/valueConsidering the convenience and universality of finite element method, as well as the contacting nonlinearity and material nonlinearity, three-dimensional finite element model of a certain type of premium connection is established with the consideration of helix angle.

scholarly journals Effects of intracorneal ring segments implementation technique and design on corneal biomechanics and keratometry in a personalized computational analysis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Niksa Mohammadi Bagheri ◽  
Mahmoud Kadkhodaei ◽  
Shiva Pirhadi ◽  
Peiman Mosaddegh
Keyword(s):  
Clinical Data ◽  
Three Dimensional ◽  
Element Model ◽  
Von Mises Stress ◽  
Patient Specific ◽  
Average Error ◽  
Constant Thickness ◽  
Arc Length ◽  
Implementation Techniques ◽  
Von Mises

AbstractThe implementation of intracorneal ring segments (ICRS) is one of the successfully applied refractive operations for the treatment of keratoconus (kc) progression. The different selection of ICRS types along with the surgical implementation techniques can significantly affect surgical outcomes. Thus, this study aimed to investigate the influence of ICRS implementation techniques and design on the postoperative biomechanical state and keratometry results. The clinical data of three patients with different stages and patterns of keratoconus were assessed to develop a three-dimensional (3D) patient-specific finite-element model (FEM) of the keratoconic cornea. For each patient, the exact surgery procedure definitions were interpreted in the step-by-step FEM. Then, seven surgical scenarios, including different ICRS designs (complete and incomplete segment), with two surgical implementation methods (tunnel incision and lamellar pocket cut), were simulated. The pre- and postoperative predicted results of FEM were validated with the corresponding clinical data. For the pre- and postoperative results, the average error of 0.4% and 3.7% for the mean keratometry value ($$\text {K}_{\text{mean}}$$ K mean ) were predicted. Furthermore, the difference in induced flattening effects was negligible for three ICRS types (KeraRing segment with arc-length of 355, 320, and two separate 160) of equal thickness. In contrast, the single and double progressive thickness of KeraRing 160 caused a significantly lower flattening effect compared to the same type with constant thickness. The observations indicated that the greater the segment thickness and arc-length, the lower the induced mean keratometry values. While the application of the tunnel incision method resulted in a lower $$\text {K}_{\text{mean}}$$ K mean value for moderate and advanced KC, the induced maximum Von Mises stress on the postoperative cornea exceeded the induced maximum stress on the cornea more than two to five times compared to the pocket incision and the preoperative state of the cornea. In particular, an asymmetric regional Von Mises stress on the corneal surface was generated with a progressive ICRS thickness. These findings could be an early biomechanical sign for a later corneal instability and ICRS migration. The developed methodology provided a platform to personalize ICRS refractive surgery with regard to the patient’s keratoconus stage in order to facilitate the efficiency and biomechanical stability of the surgery.

scholarly journals Elasto-plastic analysis of the contact region between a rigid ellipsoid and a semi-flat surface

2018 ◽  
Vol 10 (9) ◽  
pp. 168781401879739 ◽  
Author(s):  
Pengyang Li ◽  
Lingxia Zhou ◽  
Fangyuan Cui ◽  
Quandai Wang ◽  
Meiling Guo ◽  
...  
Keyword(s):  
Residual Stress ◽  
Plastic Deformation ◽  
Plastic Strain ◽  
Contact Pressure ◽  
Contact Region ◽  
Three Dimensional ◽  
Von Mises Stress ◽  
Effective Plastic Strain ◽  
Normal Forces ◽  
Von Mises

When the load acting on a mechanical structure is greater than the yield strength of the material, the contact surface will undergo plastic deformation. Cumulative plastic deformation has an important influence on the lifespan of mechanical parts. This article presents a three-dimensional semi-analytical model based on the conjugate gradient method and fast Fourier transform algorithm, with the aim of studying the characteristic parameters of the contact region between a rigid ellipsoid and elasto-plastic half-space. Moreover, normal forces and tangential traction were considered, as well as the contact pressure resulting from various sliding speeds and friction coefficients. The contact pressure, effective plastic strain, von Mises stress, and residual stress were measured and shown to increase with increasing sliding velocity. Finally, when the friction coefficient, contact pressure, and effective plastic strain are increased, the von Mises stress is also shown to increase, whereas the residual stress decreases.

Failure Analysis of Cementless Hip Joint Prosthesis

2013 ◽  
Vol 845 ◽  
pp. 403-407
Author(s):  
Natesan Dhandapani ◽  
A. Gnanavelbabu ◽  
M. Sivasankar
Keyword(s):  
Hip Joint ◽  
Low Cost ◽  
Three Dimensional ◽  
Surface Characteristics ◽  
Element Model ◽  
Von Mises Stress ◽  
Surface Model ◽  
Joint Prosthesis ◽  
Replacement Technique ◽  
Von Mises

In this changing global scenario, modification, transplantation, and replacement can be the eternal solution for most of the problems in the medical field. Hence replacement technique finds a very prominent place in medicine as a remedy having closely tied up with biomechanics. One of the most important joints in the human body is the hip joint, the big and complex joint. Many researches were conducted and many are in progress, but most of these works use simplified models with either 2D or 3D approaches. The hip joint is formed by four components like femoral head cortical bone, stem, and neck. In this system we can find orthotropic and isotropic materials working together. The main objective of this research is to develop a three dimensional surface and solid finite element model of the hip joint to predict stresses in its individual components. This model is a geometric non-linear model, which helps us understand its structural mechanical behavior, seeming to suggest with advanced research in the future new hip joint prosthesis, as well as to prove the prosthesis joint interaction before being implanted in the patient. This research explains a complete human hip joint model without cartilaginous tissue, using ANSYS 10.0 Multiphysics Analysis for nine different postures in hip joint using three different materials (CoCr, Ti6Al4V, and UHMWPE) to calculate fatigue life. The result obtained from the analysis of surface model and solid model serve to help in predicting the life cycle, surface characteristics, shear stress in XY plane, stress concentration and areas that are prone to failure. Von Mises stress on the surface of our model facilitates us to equip and design an optimized prosthesis device having unique materials composition , with a highly bio-compatible and durable alloy at a low cost could be produced. In this way, a first important step towards the structural characterization of human hip joint has been developed.

Finite Element Analysis of Gold Bonding under Different Loading Conditions

2014 ◽  
Vol 607 ◽  
pp. 713-716
Author(s):  
Wen Liang Tang ◽  
Chun Yue Huang ◽  
Tian Ming Li ◽  
Ying Liang ◽  
Guo Ji Xiong ◽  
...  
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Simulation Software ◽  
Bonding Time ◽  
Von Mises Stress ◽  
Bonding Pressure ◽  
Element Analysis ◽  
Von Mises ◽  
Three Dimensional Finite Element

In this paper, ANSYS-LSDYNA simulation software is used to build the three-dimensional finite element model of the ball bond and to get the Von Mises stress. The change of stress about the bump is researched which base on the model in different bonding pressure, bonding power and bonding time. The result show that: The stress increase with bonding pressure increase within a certain bonding pressure range, and then the stress will maintain a table number, however, the stress will continue to increase when the bonding pressure reach a certain value; increasing the bonding power, the area of lager stress will grow; prolonging the bonding time, the stress of the pad will increase with time, but when time increase to a certain value, the stress of the pad will not increase over time.

scholarly journals Assessment of stress changes in dentoalveolar and skeletal structures of the mandible with the miniplate anchored Forsus: A three-dimensional finite element stress analysis study

2017 ◽  
Vol 7 ◽  
pp. 87-93
Author(s):  
Harshal Ashok Patil ◽  
Pawankumar Dnyandeo Tekale ◽  
Veerendra V. Kerudi ◽  
Jitendra S. Sharan ◽  
Ratnadip Arunrao Lohakpure ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Three Dimensional ◽  
Element Model ◽  
Von Mises Stress ◽  
Functional Appliance ◽  
3D Finite Element ◽  
Fixed Functional Appliance ◽  
Finite Element Stress Analysis ◽  
Von Mises

ObjectiveThe study conducted to assess the effects of a fixed functional appliance (Forsus Fatigue Resistant Device; 3M Unitek, Monrovia, CA, USA) on the mandible with three-dimensional (3D) finite element stress analysis.Materials and MethodsA 3D finite element model of mandible with miniplate at mandibular symphysis was prepared using SolidEdge software along with the plate geometry. The changes were deliberated with the finite element method, in the form of highest von Mises stress and maximum principal stress regions.ResultsMore areas of stress were seen in the model of the mandible at cortical bone in canine region at bone and miniplate interface.ConclusionsThis fixed functional appliance studied by finite element model analysis caused more von Mises stress and principal stress in both the cortical bone and the condylar region.

Finite Element Analysis for the Mega Columns for XRL West Kowloon Terminus

2013 ◽  
Vol 405-408 ◽  
pp. 1139-1143
Author(s):  
Wei Su ◽  
Ying Sun ◽  
Shi Qing Huang ◽  
Ren Huai Liu
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Parametric Design ◽  
Three Dimensional ◽  
Element Model ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Von Mises ◽  
Three Dimensional Finite Element

Using ANSYS parametric design language, a three-dimensional finite element model is developed to analyze the stress distribution and the strength of the mega columns for XRL West Kowloon Terminus. The detailed von Mises stress distribution in each column, vertical stiffener plates and the diaphragm plates is obtained. From the analysis, the phenomenon of stress concentration is obvious in both upper and lower diaphragm plates. The local value of von Mises stress in them is higher than the yield stress value, which must be avoided by more detailed local structural design.

Numerical Simulation for Stress Distribution of Bones and Bone Plate Using Finite Element Method

2012 ◽  
Vol 197 ◽  
pp. 93-97 ◽  
Author(s):  
Wen Zhi Zhao ◽  
Hong Jiang ◽  
Sheng Wei He ◽  
Lu Zhang ◽  
Xue Gang Sun
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Integrated System ◽  
Bone Plate ◽  
Von Mises Stress ◽  
Dimensional Finite Element ◽  
Von Mises ◽  
Three Dimensional Finite Element ◽  
Bone Section

A three-dimensional finite element model is developed to simulate the integrated system which consists of the fractured bone (femur), bone plate and stabilization screw by using the ANSYS software. The stress and strain distribution of the integrated system is investigated. The numerical model simulates a patient’s imperfect walking under the assumption that the fractured bone is not able to support any load and all body weight was burden by bone plate in fractured bone section. The simulation results reveal that the maximum Von Mises stress on bone plate is much less than yield strength and fatigue strength of Titanium alloy.

Optimization of a Steam Turbine Blade’s Double-T Root Through Contact Surface Convexity

2016 ◽  
Author(s):  
Johanna Ehlers ◽  
Henning Ressing ◽  
Wulf-Christof von Karstedt ◽  
Daniel Rixen ◽  
Mohamed S. Gadala
Keyword(s):  
Steam Turbine ◽  
Turbine Blade ◽  
Contact Surface ◽  
Three Dimensional ◽  
Peak Stress ◽  
Element Model ◽  
Von Mises Stress ◽  
3D Fem ◽  
Fem Model ◽  
Von Mises

The turbine blade is one of the most critical components of a steam turbine. The high thermal loads and large centrifugal forces cause extreme stresses on the blade, especially on its root. This paper focuses on improving the double-T root of a turbine blade of the control stage by decreasing the root’s peak equivalent von-Mises stress. An 18% reduction was achieved in the peak stress by changing the convexity of the contact surface between the root and the groove. The equivalent von-Mises stress was determined in a static structural analysis of a three dimensional finite element model (3D FEM-model) using ANSYS Workbench. This numerical model was developed to include one blade and the associated part of the shaft, whereas the complete circle of blades was considered by applying cyclic symmetry. Furthermore, this paper includes a modal analysis comparing the natural frequencies of the initial FEM-model with the frequencies of the optimized one. The results were established by an investigation of the influence of the FEM-model’s parameters, its material properties, thermal effects, and an additional damping wire in the shroud.

Thermal Stress Comparison on Copper and Gold Wire Bonded on Aluminium Bondpad

2014 ◽  
Vol 1082 ◽  
pp. 323-326
Author(s):  
Vithyacharan Retnasamy ◽  
Zaliman Sauli ◽  
Nabilah Fathiah Abd Ghani ◽  
Hussin Kamarudin ◽  
Norhawati Ahmad ◽  
...  
Keyword(s):  
Thermal Stress ◽  
Three Dimensional ◽  
Element Model ◽  
Gold Wire ◽  
Von Mises Stress ◽  
Simulation Tool ◽  
Ball Bond ◽  
Linear Finite Element ◽  
Von Mises ◽  
Increasing Temperature

This paper reports on the thermal stress comparison between gold (Au) and copper (Cu) wires in wire bonding. The objective of this study is to examine the stress induced during different operating temperatures. ANSYS 11 has been deployed as the simulation tool for this study. This simulation was performed using a three dimensional (3D) non-linear finite element model. The gold and copper wires were attached to an aluminium bondpad on a silicon die. The results showed that when the highest stress concentrates at the area between the ball bond and the bondpad. Moreover, increasing temperature will increase the von mises stress. As for this study, the Cu wire display the greater thermal stress compared to Au wire due to its harder and stiffer material properties.

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