scholarly journals Effect of microseparation on contact mechanics in metal‐on‐metal hip replacements—A finite element analysis

2014 ◽  
Vol 103 (6) ◽  
pp. 1312-1319 ◽  
Author(s):  
Feng Liu ◽  
Sophie Williams ◽  
John Fisher
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Contact Mechanics ◽  
Element Analysis ◽  
Metal On Metal ◽  
Hip Replacements

Mechanical Behaviour of Auxetic Microstructures Using Contact Mechanics and Elastoplasticity

2016 ◽  
Vol 681 ◽  
pp. 100-116
Author(s):  
Georgios A. Drosopoulos ◽  
Nikolaos Kaminakis ◽  
Nikoletta Papadogianni ◽  
Georgios E. Stavroulakis
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Topology Optimization ◽  
Contact Mechanics ◽  
Compliant Mechanisms ◽  
Nonlinear Finite Element Analysis ◽  
Nonlinear Finite Element ◽  
Numerical Homogenization ◽  
Element Analysis ◽  
Optimization Formulation

The design of novel mechanical microstructures having auxetic behaviour is proposed in this paper using techniques of topology optimization for compliant mechanisms. The resulting microstructure can be modified in order to cover additional needs, not included in the topology optimization formulation. Classical structural optimization, contact mechanics, homogenization and nonlinear finite element analysis are used for this step. Thus, the modified microstructure or composite is studied with numerical homogenization in order to verify that it still has the wished auxetic behaviour. Finally, nonlinear finite element analysis shows how the auxetic behaviour is influenced by unilateral contact between the constituent materials, large displacements and elastoplasticity.

THE EFFECT OF ASPHERICITY OF ACETABULAR BEARING SURFACE ON CONTACT MECHANICS OF UHMWPE TOTAL HIP IMPLANTS BY FINITE ELEMENT ANALYSIS

2017 ◽  
Vol 17 (01) ◽  
pp. 1750011 ◽  
Author(s):  
XUAN ZHANG ◽  
LING WANG ◽  
XIFENG PENG ◽  
DICHEN LI ◽  
JIANKANG HE ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Contact Mechanics ◽  
Contact Pressure ◽  
Surface Profile ◽  
Surface Measurement ◽  
Element Analysis ◽  
Actual Surface ◽  
Total Hip ◽  
Measuring Machine

Asphericity and out-of-roundness are generally used to evaluate the manufacturing quality of ultra-high molecular weight polyethylene (UHMWPE) cup inner surfaces, which can potentially affect initial clinical wear and contribute to osteolysis of total hip arthroplasty. This study measured the location and magnitude of asphericity and the out-of-roundness value for four UHMWPE cups in a single set, and then investigated the effects of the asphericity on the contact mechanics of UHMWPE cups. A co-ordinate measuring machine (CMM) was used for the surface measurement and finite element analysis (FEA) was adopted for contact mechanics study. The results demonstrated that the asphericity varied between cups with the maximum value as 0.088[Formula: see text][Formula: see text][Formula: see text]0.004[Formula: see text]mm. Although such a value met the ISO specification, large difference of volume appeared for the asphericity above 0.060[Formula: see text]mm. Actual surface profile accounting for the asphericity was found to affect the value of contact pressure and contact area by around 12%. The inferior asphericity resulted in a nonsmoothly distributed contact pressure, which had a negative effect on the contact mechanics of UHMWPE cups and the edge loading was predicted to occur for the sample with a large asphericity. In conclusion, the asphericity of UHMWPE cup could affect the contact mechanics of the articular bearings and may subsequently contribute to initial wear during bedding-in phase.

The Effect of Cusp Contact in the Meshing Process for Internal Gear Pairs with few Teeth Difference

2013 ◽  
Vol 367 ◽  
pp. 63-67
Author(s):  
Yan Gang Wei ◽  
Jing Zhao
Keyword(s):  
Finite Element Method ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Contact Mechanics ◽  
Simulation Analysis ◽  
Element Analysis ◽  
Internal Gear ◽  
Gear Engagement ◽  
Meshing Process ◽  
Element Method

The model of finite element analysis is established reasonably through combining the principle of gear engagement, contact mechanics, and finite element concept and method. Simulation analysis is made for the meshing process of the internal gear pairs with few teeth difference using finite element method. It is found out that the effect of cusp contact along the direction of tooth depth will be generated in the meshing process of the internal gear pairs with few teeth difference when studying the multi-teeth contact. The complexity of multi-teeth meshing effect and the effect of the effect of cusp contact during the meshing process is pointed out.

scholarly journals Edge-loading severity as a function of cup lip radius in metal-on-metal total hips-A finite element analysis

2011 ◽  
Vol 30 (2) ◽  
pp. 169-177 ◽  
Author(s):  
Jacob M. Elkins ◽  
Karen M. Kruger ◽  
Douglas R. Pedersen ◽  
John J. Callaghan ◽  
Thomas D. Brown
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Element Analysis ◽  
Metal On Metal ◽  
Edge Loading
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