Dynamic contact stress and frictional heat analysis of femoral head-on-acetabular cup interface based on calculation and simulation methods

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Xingxing Fang ◽  
Dahan Li ◽  
Yucheng Xin ◽  
Songquan Wang ◽  
Yongbo Guo ◽  
...  

Purpose The purpose of this paper is to systematically study the dynamic contact stress, frictional heat and temperature field of femoral head-on-acetabular cup contact pairs in a gait cycle. Design/methodology/approach In this paper, four common femoral head-on-acetabular cup contact pairs are used as the research objects, mathematical calculations and finite element simulations are adopted. The contact model of hip joint head and acetabular cup was established by finite element simulation to analyze the stress and temperature distribution of the contact interface. Findings The results show that the contact stress of the head-on-cup interface is inversely proportional to the contact area; high contact stress directly leads to greater frictional heat. However, hip joints with metal-on-polyethylene or ceramic-on-polyethylene paired interfaces have lower frictional heat and show a significant temperature rise in one gait cycle, which may be related to the material properties of the acetabular cup. Originality/value Previous studies about calculating the interface frictional heat always ignore the dynamic change process in the contact load and the contact area. This study considered the dynamic changes of the contact stress and area of the femoral head-on-acetabular cup interface, and four common contact pairs were systematically analyzed.

Author(s):  
K Kim ◽  
B Forest ◽  
J Geringer

This paper describes a two-dimensional (2D) finite element simulation for fracture and fatigue behaviours of pure alumina microstructures such as those found at hip prostheses. Finite element models are developed using actual Al2O3 microstructures and a bilinear cohesive zone law. Simulation conditions are similar to those found at a slip zone in a dry contact between a femoral head and an acetabular cup of hip prosthesis. Contact stresses are imposed to generate cracks in the models. Magnitudes of imposed stresses are higher than those found at the microscopic scale. Effects of microstructures and contact stresses are investigated in terms of crack formation. In addition, fatigue behaviour of the microstructure is determined by performing simulations under cyclic loading conditions. It is shown that crack density observed in a microstructure increases with increasing magnitude of applied contact stress. Moreover, crack density increases linearly with respect to the number of fatigue cycles within a given contact stress range. Meanwhile, as applied contact stress increases, number of cycles to failure decreases gradually. Finally, this proposed finite element simulation offers an effective method for identifying fracture and fatigue behaviours of a microstructure provided that microstructure images are available.


2017 ◽  
Vol 69 (1) ◽  
pp. 71-80 ◽  
Author(s):  
Lucian Capitanu ◽  
Virgil Florescu ◽  
Liliana-Laura Badita

Purpose The purpose of this study was to realize finite element simulation in order to dynamically determine the area of the contact, the contact pressure and the strain energy density (identified as a damage function) for three different activities – normal walking, ascending stairs and descending stairs – that could be considered to define the level of the activity of the patient. Design/methodology/approach The finite element model uses a modern contact mechanism that includes friction between the metallic femoral condyles or femoral head (considered rigid) and the tibial polyethylene insert or acetabular cup (considering a non-linear behaviour). Findings For all three activities, the finite element analyses were performed, and a damage score was computed. Finally, a cumulative damage score (that accounts for all three activities) was determined, and the areas where the fatigue wear is likely to occur were identified. Originality/value A closer look at the distribution of the damage score reveals that the maximum damage is likely to occur not at the contact surface, but in the subsurface.


Author(s):  
M M Mak ◽  
A A Besong ◽  
Z M Jin ◽  
J Fisher

The contact mechanics in ceramic-on-ceramic hip implants are investigated in this study under the microseparation condition where the edge contact occurs between the superolateral rim of the acetabular cup and the femoral head. A three-dimensional finite element model is developed to examine the effect of the microseparation distance between the femoral head and the acetabular cup on the contact area and contact stresses between the bearing surfaces. It is shown that microseparation leads to edge contact and elevated contact stresses, and these are mainly dependent on the magnitude of separation, the radial clearance between the femoral head and the acetabular cup, and the cup inclination angle. For a small microseparation distance (less than the diametrical clearance), the contact occurs within the acetabular cup, and consequently an excellent agreement of the predicted contact pressure distribution is obtained between the present three-dimensional anatomical model and a simple two-dimensional axisymmetric model adopted in a previous study [5]. However, as microsegregation is increased further, edge contact between the superolateral rim and the femoral head occurs. Consequently, the predicted contact pressure is significantly increased. The corresponding contact area resembles closely the stripe wear pattern observed on both clinically retrieved and simulator-tested ceramic femoral heads [8, 9, 11]. Furthermore, introducing a fillet radius of 2.5 mm at the mouth of the acetabular cup is shown to reduce the contact stress due to edge contact, but only under relatively large microseparation distances.


2004 ◽  
Vol 126 (5) ◽  
pp. 636-640 ◽  
Author(s):  
M. C. Miller ◽  
P. Smolinski ◽  
S. Conti ◽  
K. Galik

A finite element model of a semiconstrained ankle implant with the tibia and fibula was constructed so that the stresses in the polyethylene liner could be computed. Two different widths of talar components were studied and proximal boundary conditions were computed from an inverse process providing a load of five times body weight appropriately distributed across the osseous structures. von Mises stresses indicated small regions of localized yielding and contact stresses that were similar to those in acetabular cup liners. A wider talar component with 36% more surface area reduced contact stress and von Mises stresses at the center of the polyethylene component by 17%.


2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Sunghwan Kim ◽  
Mark Carl Miller

A finite element (FE) elbow model was developed to predict the contact stress and contact area of the native humeroradial joint. The model was validated using Fuji pressure sensitive film with cadaveric elbows for which axial loads of 50, 100, and 200 N were applied through the radial head. Maximum contact stresses ranged from 1.7 to 4.32 MPa by FE predictions and from 1.34 to 3.84 MPa by pressure sensitive film measurement while contact areas extended from 39.33 to 77.86 mm2 and 29.73 to 83.34 mm2 by FE prediction and experimental measurement, respectively. Measurements from cadaveric testing and FE predictions showed the same patterns in both the maximum contact stress and contact area, as another demonstration of agreement. While measured contact pressures and contact areas validated the FE predictions, computed maximum stresses and contact area tended to overestimate the maximum contact stress and contact area.


2014 ◽  
Vol 926-930 ◽  
pp. 873-876
Author(s):  
Min Zhang ◽  
Guang Zhong Hu ◽  
Shou Ne Xiao ◽  
Yong Ming Tang

The locomotive wheelset running with a high-speed, the wheels and axles of wheelset usually assembled by interference fit, the radial contact stress produced by interference cause the friction on the contact area, the axial force and torque of the wheelset transmitted by the friction. The value of prestress produced by the magnitude of interference change small in each load case, and it plays the main role in total stress of wheelset. So it’s very important that choosing a appropriate interference for the wheelset assembly base on the results solved by the finite element contact analysis.


2021 ◽  
pp. 1-10
Author(s):  
Jin-Ah Lee ◽  
Yong-Gon Koh ◽  
Kyoung-Tak Kang

BACKGROUND: The post-cam mechanism in the posterior-stabilized (PS) implant plays an important role, such as durability and kinematic performances, in total knee arthroplasty (TKA). OBJECTIVE: The purpose of this study was to evaluate the difference in the kinematics and contact stress of five post-cam designs, which are flat-and-flat, curve-and-curve (concave), curve-and-curve (concave and convex), helical, and asymmetrical post-cam designs, using three-dimensional finite element models. METHODS: We designed the post-cam model with five different geometries. The kinematics, contact stress, and contact area were evaluated in the five post-cam designs under gait cycle loading conditions using the finite element method. RESULTS: There were no differences in the contact stress and area on the tibial insert in all designs. The largest internal rotation was shown in the swing phase for the helical design, and the largest tibial posterior translation was observed for the curve-and-curve (concave) design. The curve-and-curve (concave) design showed the lowest contact stress and the largest posterior tibial translation during the gait cycle. CONCLUSIONS: Considering the kinematics and contact stress, we found that the curve-and-curve (concave) design was more stable than other designs. From the results, we found the important factors of TKA implant considering stability and kinematics.


Author(s):  
M M Mak ◽  
Z M Jin

The contact mechanics in ceramic-on-ceramic hip implants has been analysed in this study using the finite element method. Only the ideal conditions where the contact occurs within the acetabular cup were considered. It has been shown that the contact pressure distribution and the contact area at the main articulating bearing surfaces depend largely on design parameters such as the radial clearance between the femoral head and the acetabular cup, as well as the thickness of the ceramic insert. For the ceramic-on-ceramic hip implants used in clinics today, with a minimum 5-mm-thick ceramic insert, it has been shown that the radius of the contact area between the femoral head and the acetabular cup is relatively small compared with that of the femoral head and the ceramic insert thickness. Consequently, Hertz contact theory can be used to estimate the contact parameters such as the maximum contact pressure and the contact area.


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