The natural synovial joint: A finite element investigation of biphasic surface amorphous layer lubrication under dynamic loading conditions

2006 ◽  
Vol 220 (8) ◽  
pp. 671-681 ◽  
Author(s):  
S Graindorge ◽  
W Ferrandez ◽  
Z-M Jin ◽  
E Ingham ◽  
J Fisher
Keyword(s):  
Finite Element ◽  
Dynamic Loading ◽  
Amorphous Layer ◽  
Loading Conditions ◽  
Synovial Joint ◽  
Dynamic Loading Conditions

Development and Verification of a Dynamic TKR Model

2002 ◽  
Author(s):  
Jason P. Halloran ◽  
Anthony J. Petrella ◽  
Paul J. Rullkoetter
Keyword(s):  
Finite Element ◽  
Contact Mechanics ◽  
Dynamic Loading ◽  
Soft Tissues ◽  
Dynamic Models ◽  
Total Joint Replacement ◽  
Fe Model ◽  
Loading Conditions ◽  
Dynamic Loading Conditions

The success of current total knee replacement (TKR) devices is contingent on the kinematics and contact mechanics during in vivo activity. Indicators of potential clinical performance of total joint replacement devices include contact stress and area due to articulations, and tibio-femoral and patello-femoral kinematics. An effective way of evaluating these parameters during the design phase or before clinical use is via computationally efficient computer models. Previous finite element (FE) knee models have generally been used to determine contact stresses and/or areas during static or quasi-static loading conditions. The majority of knee models intended to predict relative kinematics have not been able to determine contact mechanics simultaneously. Recently, however, explicit dynamic finite element methods have been used to develop dynamic models of TKR able to efficiently determine joint and contact mechanics during dynamic loading conditions [1,2]. The objective of this research was to develop and validate an explicit FE model of a TKR which includes tibio-femoral and patello-femoral articulations and surrounding soft tissues. The six degree-of-freedom kinematics, kinetics and polyethylene contact mechanics during dynamic loading conditions were then predicted during gait simulation.

Analyzing Hertzian contact stress developed in a double row spherical roller bearing and its effect on fatigue life

2016 ◽  
Vol 68 (3) ◽  
pp. 361-368 ◽  
Author(s):  
Dhaval B. Shah ◽  
Kaushik M. Patel ◽  
Ruchik D. Trivedi
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Dynamic Loading ◽  
Contact Stress ◽  
Roller Bearing ◽  
Loading Conditions ◽  
Double Row ◽  
Content Type ◽  
Element Approach ◽  
Dynamic Loading Conditions

Purpose The purpose of this paper is to describe a method permitting the creation of a realistic model of spherical roller bearing with the aim of determining contact stress and fatigue life based on dynamic loading conditions. The paper also aims to recognize the effect of tolerance values on contact stress and fatigue life. Motion and load transmission in spherical roller bearing occurs within the assembly by elliptical curved contacting surfaces. The stress produced by the transmitted load would be very high because of least contacting area between these surfaces. Design/methodology/approach The paper describes a methodology to determine contact stress using analytically as well as finite element method for spherical roller bearing. The comparison for the both each approach for contact stress at different loading condition is carried out. Prediction of fatigue life based on dynamic loading conditions for bearing is also determined using finite element model. The effect on induced contact stress and fatigue life by varying tolerances on inner race dimensions have been found out. Findings The paper suggests that the maximum stress produces at the start or end of the contacting arc under static loading condition in spherical roller bearing. The analytical and finite element approach is in good agreement. The fatigue life prediction is useful for selecting loading conditions for various applications of double row spherical roller bearing. Tolerance level at inner ring raceway radius is kept high because of manufacturing constrain of complex curvature geometric shape. Research limitations/implications The present approach does not consider dynamic loading conditions for contact stress analysis. Therefore, researchers are encouraged to analyze the effect of wear, lubrication and other tribological aspects on bearing life. Originality/value The paper includes determination of contact stress and prediction of fatigue life for spherical roller bearing using analytical as well as finite element approach. The tolerance values at inner race are identified as per manufacturing constraint based on contact stress and fatigue life.

Ductile Fracture Simulation Considering Strain Rate Loading Effect

2015 ◽  
Author(s):  
Hyun-Suk Nam ◽  
Ji-Soo Kim ◽  
Yun-Jae Kim ◽  
Jin-Weon Kim ◽  
Chang-Young Oh
Keyword(s):  
Finite Element ◽  
Strain Rate ◽  
Dynamic Loading ◽  
Fracture Strain ◽  
Fracture Toughness Test ◽  
Loading Conditions ◽  
Loading Effect ◽  
Fracture Simulation ◽  
Dynamic Loading Conditions ◽  
Strain Model

This paper is based on a ductile failure simulation under dynamic loading conditions using finite element (FE) analyses. Recently a simple finite element method in a quasi-static test has been proposed to implement fracture simulation based on the well-known stress modified fracture strain model. The stress-modified fracture strain model is determined to be incremental damage in terms of stress triaxiality and fracture strain for dimple fracture from tensile test result with FE analyses technique. Since dynamic loading effect is especially important to assess pipe with crack-like defect, this work propose the integrated model which combines quasi-static with dynamic loading effect. In order to validate stress-modified fracture strain model in dynamic loading conditions, this paper compares results of FE analysis using proposed method with strain dependent smooth bar tests and notch tensile tests using Johnson-Cook equation. In conclusion, the stress-modified fracture strain model criterion can be calibrated by FE analyses with strain rate dependent fracture toughness test results.

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