scholarly journals Computer Simulation of Optimal Lipped Polyethylene Liner Orientation Against Prosthetic Impingement

2021 ◽  
Author(s):  
Yi Hu ◽  
Xianhao Zhou ◽  
Hua Qiao ◽  
Zhenan Zhu ◽  
Huiwu Li ◽  
...  
Keyword(s):  
Hip Replacement ◽  
External Rotation ◽  
Three Dimensional ◽  
Axial Rotation ◽  
Acetabular Anteversion ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Optimal Orientation ◽  
The Impact ◽  
Replacement Prosthesis

Abstract Background: Lipped or elevated acetabular liners are to improve posterior stability and are widely used in hip arthroplasty. However, concerns of increasing impingement exist when using such liners and optimal orientation of the elevated rim remains unknown. We aimed to identify the impact of lipped liner on the range of motion (ROM) before impingement and propose its optimal orientation.Methods: An isochoric three-dimensional model of a general hip-replacement prosthesis was generated and flex-extension, add-abduction, axial rotation was simulated on a computer. The maximum ROM of the hip was measured before the neck impinged on the liner. Different combinations of acetabular anteversion angles ranging from 5 to 30 degrees and lipped liner orientations from posterior to anterior were tested. Results: When acetabular anteversion was 10 or 15 degrees, placing the lip of the liner in the posterosuperior of the acetabulum allowed satisfactory ROM in all directions. When acetabular anteversion was 20 degrees, extension and external rotation were restricted. Adjusting the lip to the superior restored satisfactory ROM. When acetabular anteversion was 25 degrees, only placing the lip into the antero-superior could increase extension and external rotation to maintain satisfactory ROM.Conclusions: This study showed that optimal lipped liner orientation should be depend on acetabular anteversion. When acetabular anteversion was smaller than 20 degrees, placing lip in the posterior allowed an optimally ROM. When acetabular anteversion was greater than 20 degrees, adjusting lip to the anterior allowed a comprehensive larger ROM to avoid early impingement.

scholarly journals Forecasting of Surface Currents via Correcting Wind Stress with Assimilation of High-Frequency Radar Data in a Three-Dimensional Model

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Lei Ren ◽  
Stephen Nash ◽  
Michael Hartnett
Keyword(s):  
Data Assimilation ◽  
High Frequency ◽  
Three Dimensional ◽  
Hf Radar ◽  
Surface Velocity ◽  
Shear Stresses ◽  
Surface Currents ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
The Impact

This paper details work in assessing the capability of a hydrodynamic model to forecast surface currents and in applying data assimilation techniques to improve model forecasts. A three-dimensional model Environment Fluid Dynamics Code (EFDC) was forced with tidal boundary data and onshore wind data, and so forth. Surface current data from a high-frequency (HF) radar system in Galway Bay were used for model intercomparisons and as a source for data assimilation. The impact of bottom roughness was also investigated. Having developed a “good” water circulation model the authors sought to improve its forecasting ability through correcting wind shear stress boundary conditions. The differences in surface velocity components between HF radar measurements and model output were calculated and used to correct surface shear stresses. Moreover, data assimilation cycle lengths were examined to extend the improvements of surface current’s patterns during forecasting period, especially for north-south velocity component. The influence of data assimilation in model forecasting was assessed using a Data Assimilation Skill Score (DASS). Positive magnitude of DASS indicated that both velocity components were considerably improved during forecasting period. Additionally, the improvements of RMSE for vector direction over domain were significant compared with the “free run.”

Simulating the Behaviour and Fate of an Oil Spill Using a Coupled Three-Dimensional Hydrodynamic Model

2014 ◽  
Vol 2014 (1) ◽  
pp. 901-918
Author(s):  
James A. Stronach ◽  
Aurelien Hospital
Keyword(s):  
Oil Spill ◽  
Hydrodynamic Model ◽  
Three Dimensional ◽  
Local Network ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Near Surface ◽  
Water Properties ◽  
Response Planning ◽  
The Impact

ABSTRACT Oil behavior and fate have been simulated extensively by several spill models. These simulations can be greatly enhanced by the use of a coupled three-dimensional model of currents and water properties to determine oil transport and weathering, both on the water surface and in the water column. Several physical and chemical processes such as vertical dispersion in response to wave action, resurfacing when waves die down, sinking through loss of volatiles and dissolution are essential in assessing the impact of an oil spill on the environment. Dissolution is especially important, considering the known toxicity of several of the constituents of liquid hydrocarbons. For this study, a three-dimensional hydrodynamic model of coastal British Columbia was coupled to an oil trajectory and weathering model in order to simulate the complete fate and behaviour of surface, shoreline-retained, dissolved, sunken and dispersed oil. Utilization of a three-dimensional model is the key to adequately modelling the transport of a spill in an estuarine region such as in the Strait of Georgia, B.C., where the distribution of currents and water properties is strongly affected by estuarine processes: the Fraser River enters at the surface and oceanic waters from the Pacific enter as a deep inflow. Three-dimensional currents and water properties were provided by the hydrodynamic model, H3D, a semi-implicit model using a staggered Arakawa grid and variable number of layers in the vertical direction to resolve near-surface processes. Waves were simulated using the wave model SWAN. Winds were obtained from the local network of coastal light stations and wind buoys. Stochastic modelling was conducted first, using only surface currents, to determine probabilistic maps of the oil trajectory on water and statistical results were extracted, such as the amount of shoreline oiled and the amount of oil evaporated, both for the ensemble of simulations constituting the stochastic simulation, as well as for any particular individual simulation. Deterministic scenarios were then selected and the fate of the oil, such as the dissolved and sunken fractions, was tracked over a 14 day period on the three-dimensional grid. This method has been used for environmental impact assessment and spill response planning.

Research of the Installation Angle of New Rotor Impact Plate Based on EDEM

2011 ◽  
Vol 80-81 ◽  
pp. 1133-1137
Author(s):  
De Rong Duan ◽  
Fang Zhao ◽  
Song Wang ◽  
Xian Xin Chen
Keyword(s):  
Dynamic Simulation ◽  
Impact Force ◽  
Three Dimensional ◽  
Substantial Effect ◽  
Maximum Speed ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Installation Angle ◽  
Impact Plate ◽  
The Impact

The three-dimensional model of new rotor was imported into EDEM for dynamic simulation, the maximum speed and force were analysied in the EDEM,indicating that the material along the deterministic trajectory collide with the impact plate for second acceleration after the first acceleration in new rotor, the velocity after second acceleration was 2.3 times than the first acceleration.The impact force and angle did not substantial effect on the second acceleration by comprehensive comparing,the 69m/s speed and less impact force were generated in the new rotor with 2° impact plate installation angle.

The Dynamic Simulation Study of WN Gear Pair after Coupling Tribology

2014 ◽  
Vol 577 ◽  
pp. 214-217
Author(s):  
Yu Guang Li ◽  
Guo Qing Zhang
Keyword(s):  
Dynamic Simulation ◽  
Three Dimensional ◽  
Dynamic Contact ◽  
Axial Vibration ◽  
Dimensional Model ◽  
Analysis Model ◽  
Ansys Software ◽  
Three Dimensional Model ◽  
Dimensional Simulation ◽  
The Impact

Based on WN gear characteristics and considering system error, a multi-degree-freedom (Tangential-Radial-Axial) dynamics analysis model after coupling friction was established. In this article, we established the three-dimensional solid model by using PROE and then imported WN gear’ three-dimensional model into Ansys software through the data interface of Ansys software and PROE software and conducted a three-dimensional simulation anasys of the impact of dynamic contact. By applying load, the stress analysis of WN gear was conducted and the WN gear’s the effective stress clouds was gotten. Meanwhile, basing on ANSYS / LS-DYNA, it established the rigid-flexible body of gear dynamic contact model and analyzed the dynamic simulation anasys of WN gear. The results demonstrated that the tangential and axial vibration of double arc gear was significantly greater than the radial vibration.

A Three-Dimensional Model of Droplet Impinging, Solidification and Suspension on the Substrate

2011 ◽  
Vol 346 ◽  
pp. 222-227
Author(s):  
Sheng Zhu ◽  
Feng Liang Yin ◽  
Jian Liu ◽  
Yuan Yuan Liang
Keyword(s):  
Surface Tension ◽  
Manufacturing Process ◽  
Three Dimensional ◽  
Metal Droplet ◽  
The Body ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
High Impact Velocity ◽  
The Impact ◽  
First Time

A three-dimensional model was built to study a molten metal droplet impact on an edge of the substrate in droplet deposition manufacturing process for the first time. The whole calculation domain, including the substrate, was described using same fluid conservation equations, which is to say that the remolding and solidification of substrate was considered also. Droplet free surface was tracked by volume-of-fluid (VOF) algorithm. The effect of surface tension on the droplet was taken into consideration by means of considering surface tension to be a component of the body force. The simulated results show that the droplet in liquid phase can keep suspending on the substrate at a role of surface tension. A too high impact velocity would make parts of droplet splash away the substrate which is not allowed in manufacturing process. The offset between edge of droplet and side edge of substrate influences dramatically the impact of the droplet.

Numerical Simulation on Drawing Deep of Cylindrical Pieces Based on Dynaform

2014 ◽  
Vol 684 ◽  
pp. 252-258 ◽  
Author(s):  
Jun Hong Wang ◽  
Xu Dong Bao ◽  
Hai Mei Feng ◽  
Chang Du
Keyword(s):  
Numerical Simulation ◽  
Three Dimensional ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Forming Process ◽  
Minimum Thickness ◽  
Optimum Parameters ◽  
Design And Manufacture ◽  
The Impact

Abstract: The design and manufacture of mold often rely on the experience of the designers, which led to the fact that the mold needs to be repeatedly debugged and corrected. Numerical simulation technology enables the simulation of the forming process of sheet metal and prediction of defects in design, thus to improve labor efficiency, save time and reduce costs. In this paper, the software Dynaform is used as a platform and a three-dimensional model is built to numerical simulate and analyze the drawing deep of a typical thin-walled cylindrical piece.Orthogonal experimentis adopted to analyze the impact of BHF, punching speed and punch-die gap on forming quality of the drawing pieces. With minimum thickness and wrinkling as indicators, the impact of various factors is analyzed and a set of optimum parameters is found out that is, BHF is 20kN, punching speed is 2000mm / s and punch-die gap is 0.9mm.

The Impact of Social Influence Pressures, Commitment, and Personality on Judgments by Auditors: Evidence from Japan

2017 ◽  
Vol 16 (3) ◽  
pp. 17-34 ◽  
Author(s):  
Noriyuki Tsunogaya ◽  
Satoshi Sugahara ◽  
Parmod Chand
Keyword(s):  
Organizational Commitment ◽  
Social Influence ◽  
Significant Influence ◽  
Three Dimensional ◽  
Personal Attributes ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Audit Firms ◽  
Conformity Pressure ◽  
The Impact

ABSTRACT We examine whether obedience and conformity pressures generated by superiors (partners) and colleagues within audit firms cause dysfunctional audit behavior in Japan. We also investigate whether high levels of professional and organizational commitment and the personal attributes of auditors mitigate these pressures. The results indicate that obedience pressure can impair the judgments of auditors, whereas conformity pressure does not have a significant influence. The application of a three-dimensional model of commitment and a five-dimensional scale of individual personalities reveals that dysfunctional audit behavior can be mitigated by enhancing affective and normative commitment, and by addressing highly masculine characteristics in individual auditors.

Velocity, Pressure, and Dam-Break Similarity of Green Water Flow on a 3D Structure

2011 ◽  
Author(s):  
Kuang-An Chang ◽  
Kusalika Ariyarathne ◽  
Richard Mercier
Keyword(s):  
Vertical Wall ◽  
Three Dimensional ◽  
Dam Break ◽  
Green Water ◽  
Breaking Wave ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Wave Condition ◽  
Wall Impingement ◽  
The Impact

Flow dynamics of green water due to plunging breaking waves interacting with a simplified, three-dimensional model structure was investigated in laboratory. Two breaking wave conditions were tested: one with waves impinging and breaking on the vertical wall of the model at the still water level (referred as wall impingement) and the other with waves impinging and breaking on the horizontal deck surface (referred as deck impingement). The bubble image velocimetry (BIV) technique was used to measure the flow velocity. Measurements were taken on a vertical plane located at the center of the deck surface and a horizontal plane located slightly above the deck surface. The applicability of dam-break theory on green water velocity prediction for the three-dimensional model was also investigated. Furthermore, pressure measurements were performed at several locations above the horizontal deck surface for the wall impingement wave condition. Predictions of maximum impact pressure based on the measured pressure and flow velocities were investigated using the impact coefficient approach that links pressure with kinetic energy.

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