The Effect of Shape Variables of Tibial Plateau on Tibio-femoral Movement Based on a Three-dimensional Anatomical Dynamic Model

2006 ◽  
Keyword(s):  
Dynamic Model ◽  
Tibial Plateau ◽  
Three Dimensional

Low-Degree Tibial Slope Angle Prevents Component Overhang by Enlarging the Lateral Plateau Surface Area in Total Knee Arthroplasty

2020 ◽  
Author(s):  
Mehmet Emin Simsek ◽  
Mustafa Akkaya ◽  
Safa Gursoy ◽  
Özgür Kaya ◽  
Murat Bozkurt
Keyword(s):  
Total Knee Arthroplasty ◽  
Surface Area ◽  
Knee Arthroplasty ◽  
Tibial Plateau ◽  
Slope Angle ◽  
Three Dimensional ◽  
Tibial Slope ◽  
Total Knee ◽  
Lateral Plateau ◽  
Gender Groups

AbstractThis study aimed to investigate whether overhang or underhang around the tibial component that occurs during the placement of tibial baseplates was affected by different slope angles of the tibial plateau and determine the changes in the lateral and medial plateau diameters while changing the slope angle in total knee arthroplasty. Three-dimensional tibia models were reconstructed using the computed tomography scans of 120 tibial dry bones. Tibial plateau slope cuts were performed with 9, 7, 5, 3, and 0 degrees of slope angles 2-mm below the subchondral bone in the deepest point of the medial plateau. Total, lateral, and medial tibial plateau areas and overhang/underhang rates were measured at each cut level. Digital implantations of the asymmetric and symmetric tibial baseplates were made on the tibial plateau with each slope angles. Following the implantations, the slope angle that prevents overhang or underhang at the bone border and the slope angle that has more surface area was identified. A significant increase was noted in the total tibial surface area, lateral plateau surface area, and lateral anteroposterior distance, whereas the slope cut angles were changed from 9 to 0 degrees in both gender groups. It was found that the amount of posteromedial underhang and posterolateral overhang increased in both the asymmetric and symmetric tibial baseplates when the slope angle was changed from 0 to 9 degrees. Although the mediolateral diameter did not change after the proximal tibia cuts at different slope angles, the surface area and anteroposterior diameter of the lateral plateau could change, leading to increased lateral plateau area. Although prosthesis designs are highly compatible with the tibial surface area, it should be noted that the component overhangs, especially beyond the posterolateral edge, it can be prevented by changing the slope cut angle in males and females.

A Three-Dimensional Dynamic Model of Startup Heating during Induction Melting in a Cold Crucible

2021 ◽  
Vol 92 (3) ◽  
pp. 150-153
Author(s):  
I. N. Skrigan ◽  
D. B. Lopukh ◽  
A. V. Vavilov ◽  
A. P. Martynov
Keyword(s):  
Dynamic Model ◽  
Three Dimensional ◽  
Induction Melting ◽  
Cold Crucible

Force-based delay compensation for hardware-in-the-loop simulation divergence of 6-DOF space contact

2017 ◽  
Vol 233 (1) ◽  
pp. 151-165
Author(s):  
Qian Wang ◽  
Chenkun Qi ◽  
Feng Gao ◽  
Xianchao Zhao ◽  
Anye Ren ◽  
...  
Keyword(s):  
Dynamic Model ◽  
Dynamic Models ◽  
Contact Process ◽  
Three Dimensional ◽  
Compensation Method ◽  
Degree Of Freedom ◽  
Hardware In The Loop ◽  
Delay Compensation ◽  
Measurement Delay ◽  
Six Degree Of Freedom

The contact process of a space docking device needs verification before launching. The verification cannot only rely on the software simulation since the contact dynamic models are not accurate enough yet, especially when the geometric shape of the device is complex. Hardware-in-the-loop simulation is a choice to perform the ground test, where the contact dynamic model is replaced by a real device and the real contact occurs. However, the Hardware-in-the-loop simulation suffers from energy increase and instability since time delay is unavoidable. The existing delay compensation methods are mainly focused on a uniaxial or three-dimensional contact. In this paper, a force-based delay compensation method is proposed for the hardware-in-the-loop simulation of a six degree-of-freedom space contact. A six degree-of-freedom dynamic model of the spacecraft motion is derived, and a six degree-of-freedom delay compensation method is proposed. The delay is divided into track delay and measurement delay, which are compensated individually. Experiment results show that the proposed delay compensation method is effective for the six degree-of-freedom space contact.

Fully Coupled Three-Dimensional Dynamic Response of a TLP Floating Wind Turbine in Waves and Wind

2012 ◽  
Author(s):  
G. K. V. Ramachandran ◽  
H. Bredmose ◽  
J. N. Sørensen ◽  
J. J. Jensen
Keyword(s):  
Wind Turbine ◽  
Dynamic Model ◽  
Three Dimensional ◽  
Geographic Location ◽  
Climatic Conditions ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Total System ◽  
Wave Loads ◽  
Aerodynamic Loads

A dynamic model for a tension-leg platform (TLP) floating offshore wind turbine is proposed. The model includes three-dimensional wind and wave loads and the associated structural response. The total system is formulated using 17 degrees of freedom (DOF), 6 for the platform motions and 11 for the wind turbine. Three-dimensional hydrodynamic loads have been formulated using a frequency- and direction-dependent spectrum. While wave loads are computed from the wave kinematics using Morison’s equation, aerodynamic loads are modelled by means of unsteady Blade-Element-Momentum (BEM) theory, including Glauert correction for high values of axial induction factor, dynamic stall, dynamic wake and dynamic yaw. The aerodynamic model takes into account the wind shear and turbulence effects. For a representative geographic location, platform responses are obtained for a set of wind and wave climatic conditions. The platform responses show an influence from the aerodynamic loads, most clearly through a quasi-steady mean surge and pitch response associated with the mean wind. Further, the aerodynamic loads show an influence from the platform motion through more fluctuating rotor loads, which is a consequence of the wave-induced rotor dynamics. In the absence of a controller scheme for the wind turbine, the rotor torque fluctuates considerably, which induces a growing roll response especially when the wind turbine is operated nearly at the rated wind speed. This can be eliminated either by appropriately adjusting the controller so as to regulate the torque or by optimizing the floater or tendon dimensions, thereby limiting the roll motion. Loads and coupled responses are predicted for a set of load cases with different wave headings. Based on the results, critical load cases are identified and discussed. As a next step (which is not presented here), the dynamic model for the substructure is therefore being coupled to an advanced aero-elastic code Flex5, Øye (1996), which has a higher number of DOFs and a controller module.

Study of a synchronizer mechanism through multibody dynamic analysis

2018 ◽  
Vol 233 (6) ◽  
pp. 1601-1613 ◽  
Author(s):  
Ali Farokhi Nejad ◽  
Giorgio Chiandussi ◽  
Vincenzo Solimine ◽  
Andrea Serra
Keyword(s):  
Dynamic Model ◽  
Three Dimensional ◽  
Time Estimation ◽  
Test Rig ◽  
Operational Conditions ◽  
Multibody Dynamic ◽  
Dynamic Analyses ◽  
Single Cone ◽  
Good Agreement ◽  
Numerical Approaches

The synchronizer mechanism represents the essential component in manual, automatic manual, and dual-clutch transmissions. This paper describes a multibody dynamic model for analysis of a synchronizer mechanism subjected to different operational conditions. The three-dimensional multi-dynamic model is developed to predict the dynamic response of synchronizer, especially for calculation of synchronization time. For the purpose of validation, three different synchronizers (single-cone, double-cone, and triple-cone synchronizers) were used on the test rig machine. For the purpose of synchronizing time estimation, an analytical formulation is proposed. The results of the analytical and multibody dynamic analyses were compared with the experimental data, showing a good agreement. The results of analytical and numerical approaches show that the predicted time of synchronization is more precise than previous works. A sensitivity analysis was performed on the single-cone synchronizer, and the effect of tolerance dimension on the dynamic behavior of the synchronizer was reported.

scholarly journals Finite-element analysis of the proximal tibial sclerotic bone and different alignment in total knee arthroplasty

2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Ye-Ran Li ◽  
Yu-Hang Gao ◽  
Chen Yang ◽  
Lu Ding ◽  
Xuebo Zhang ◽  
...  
Keyword(s):  
Finite Element ◽  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Tibial Plateau ◽  
Three Dimensional ◽  
Genu Varum ◽  
Sclerotic Bone ◽  
Dimensional Measurements ◽  
Tibial Cut ◽  
Total Knee

Abstract Background Despite potential for improving patient outcomes, studies using three-dimensional measurements to quantify proximal tibial sclerotic bone and its effects on prosthesis stability after total knee arthroplasty (TKA) are lacking. Therefore, this study aimed to determine: (1) the distribution range of tibial sclerotic bone in patients with severe genu varum using three-dimensional measurements, (2) the effect of the proximal tibial sclerotic bone thickness on prosthesis stability according to finite-element modelling of TKA with kinematic alignment (KA), mechanical alignment (MA), and 3° valgus alignment, and (3) the effect of short extension stem augment utilization on prosthesis stability. Methods The sclerotic bone in the medial tibial plateau of 116 patients with severe genu varum was measured and classified according to its position and thickness. Based on these cases, finite-element models were established to simulate 3 different tibial cut alignments with 4 different thicknesses of the sclerotic bone to measure the stress distribution of the tibia and tibial prosthesis, the relative micromotion beneath the stem, and the influence of the short extension stem on stability. Results The distribution range of proximal tibial sclerotic bone was at the anteromedial tibial plateau. The models were divided into four types according to the thickness of the sclerotic bone: 15 mm, 10 mm, 5 mm, and 0 mm. The relative micromotion under maximum stress was smallest after MA with no sclerotic bone (3241 μm) and largest after KA with 15 mm sclerotic bone (4467 μm). Relative micromotion was largest with KA and smallest with MA in sclerotic models with the same thickness. Relative micromotion increased as thickness of the sclerotic bone increased with KA and MA (R = 0.937, P = 0.03 and R = 0.756, P = 0.07, respectively). Relative micromotion decreased with short extension stem augment in the KA model when there was proximal tibial sclerotic bone. Conclusions The influence of proximal tibial sclerotic bone on prosthesis’s stability is significant, especially with KA tibial cut. Tibial component’s short extension stem augment can improve stability.

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