Computer Simulation of the Coupled Analysis of Piston Secondary Motion and EHD Lubrication Based on Flexible Multi-Body Dynamics

2014 ◽  
Vol 494-495 ◽  
pp. 729-732
Author(s):  
Zhen Yu Yang ◽  
Wei Zheng Zhang
Keyword(s):  
Computer Simulation ◽  
Smooth Surface ◽  
Coupled Model ◽  
High Load ◽  
Coupled Analysis ◽  
Asperity Contact ◽  
Ehd Lubrication ◽  
Body Dynamics ◽  
Secondary Motion ◽  
Multi Body

A coupled model of piston secondary motion and mixed hydrodynamic lubricated was established based on flexible multi-Body dynamics. The model included elastic deformation and roughness of the two surfaces. The effects of rough surface compared to absolutely smooth surface on piston secondary motion mixed lubrication are discussed. The results show that roughness of the surface can make the fluid a better way to lubricate the surface and decrease the secondary motion, but in the high load asperity contact will occur.

Coupled Analysis of Thermo-Fluid-Flexible Multi-body Dynamics of a Two-Dimensional Engine Nozzle

2017 ◽  
Vol 18 (1) ◽  
pp. 70-81 ◽  
Author(s):  
WonJong Eun ◽  
JaeWon Kim ◽  
Oh-Joon Kwon ◽  
Chanhoon Chung ◽  
Sang-Joon Shin ◽  
...  
Keyword(s):  
Coupled Analysis ◽  
Two Dimensional ◽  
Body Dynamics ◽  
Multi Body

Coupled analysis of the unsteady aerodynamics and multi-body dynamics of a small car overtaking a coach

2019 ◽  
Vol 233 (14) ◽  
pp. 3684-3699 ◽  
Author(s):  
Jun Liu ◽  
Zhengqi Gu ◽  
Taiming Huang ◽  
Shuya Li ◽  
Ledian Zheng ◽  
...  
Keyword(s):  
Adverse Effect ◽  
Unsteady Aerodynamics ◽  
Coupled Analysis ◽  
Detached Eddy Simulation ◽  
Aerodynamic Loads ◽  
Unsteady Aerodynamic ◽  
Eddy Simulation ◽  
Body Dynamics ◽  
Vehicle Motion ◽  
Multi Body

The severe additional aerodynamic loads that are generated on a small car when overtaking a coach have an adverse effect on the car handling stability and its safety. In this article, a two-way coupling of the unsteady aerodynamics and multi-body dynamics is performed in order to study the mutual interactions of a car in an overtaking maneuver with a coach. The unsteady aerodynamic interactions are obtained by using SST (Menter) K-Omega Detached Eddy Simulation and overset mesh technology. The aerodynamics couple the multi-body dynamics, taking into account the effects of the transverse spacing and the cross winds. To validate the necessity of the two-way coupling method, a one-way coupling of the aerodynamics to the vehicle motion is also conducted. Finally, by comparing the aerodynamic loads and the dynamic response of the overtaking car in different overtaking maneuvers between one- and two-way coupling, the results show that it should be considered with two-way coupling analyses of the car while overtaking a coach, particularly under the severe conditions of a lower transverse spacing or the crosswinds.

Modeling and Simulation of Flexible Hydraulic Robotic Arm

2012 ◽  
Vol 538-541 ◽  
pp. 773-776 ◽  
Author(s):  
Li Dai ◽  
Da Lu Xu ◽  
Yu Liu ◽  
Jian Wang
Keyword(s):  
Coupled Model ◽  
Position Angle ◽  
Hydraulic Cylinder ◽  
Simulation Software ◽  
Robotic Arm ◽  
Body Dynamics ◽  
Hydraulic Cylinders ◽  
Concrete Pump Truck ◽  
Concrete Pump ◽  
Multi Body

The flexible robotic arm drived by hydraulic are widely applied in most kinds of large engineering equipments, such as concrete pump truck, bridge monitor truck,etc. Nevertheless, the flexible distortion always break the precision of end-position and cause liberation of the whole arm system. In this paper, the movement of flexible hydraulic robotic arm and hydraulic cylinders are separately analyzed with flexible multi-body dynamics. And the dynamic differential equation is built with the driving force of the hydraulic cylinder as the main force. The equation is based on the theory of flexible multi-body dynamics, building the coupled model of robotic arm system and hydraulic-driving system to study the relation between the end-position, angle and the hydraulic system. What’s more, the simulation model of the mechanical arms is built by the dynamic simulation software. The project will theorectically support the intelligent control or auxiliary control of large engineering equipments.

Failure Analysis of Planetary Gear Shaft of Power Split Device Based on Multi-Body Dynamics

2013 ◽  
Vol 433-435 ◽  
pp. 17-20 ◽  
Author(s):  
Yan Liu ◽  
Jing Fang Ji ◽  
Long Kong ◽  
Yan Li ◽  
Ji Xin Wang
Keyword(s):  
Hybrid Electric Vehicle ◽  
Coupled Model ◽  
Planetary Gear ◽  
Threshold Function ◽  
Power Performance ◽  
Body Dynamics ◽  
Power Split ◽  
The Moment ◽  
Multi Body ◽  
And Control

Power split device (PSD) affects the power performance and control strategy of hybrid electric vehicle (HEV). In this paper, a new threshold function for wavelet denoising is used to reduce noise in test torque and rotational speed data. The dynamic simulation is carried out at the moment of planetary gear shaft (PGS) failure, after the rigid-flexible coupled model of PSD is established. According to the obtained stress of PGS, analysis of PGS fracture is verified.

Lubrication Simulation of Main Bearing about a Marine Diesel Engine Based on Multi-Body Dynamics and Elastohydrodynamic

2011 ◽  
Vol 347-353 ◽  
pp. 2679-2683
Author(s):  
Li Dui Wei ◽  
Shu Lin Duan ◽  
Qi Li Wu ◽  
Ji Wu ◽  
Wei Guo
Keyword(s):  
Diesel Engine ◽  
Load Condition ◽  
Engine Block ◽  
Asperity Contact ◽  
The Finite Element Method ◽  
Main Bearing ◽  
Working Cycle ◽  
Body Dynamics ◽  
Marine Diesel ◽  
Multi Body

The purpose of this paper is to find a method to study the lubrication character of the main bearings and load condition of the crankshaft about the marine two-stroke diesel engine. Based on the finite element method, multi-body dynamics, elastohydrodynamic and Green-Tripp theory about contact, the simulation of coupling between the elastic crankshaft and engine block is carried out. The load of main bearings, the minimum of oil film thick, orbital path of journal, average of asperity contact pressure are explored. The results indicate that the lubrication is good except No.2 main bearing. Parts of main bearings appear three peaks in a working cycle, which shows that above theory and elastic crankshaft and engine block is obligatory to simulate the lubrication and load condition accurately.

scholarly journals Estimating maximum bite performance in Tyrannosaurus rex using multi-body dynamics

2012 ◽  
Vol 8 (4) ◽  
pp. 660-664 ◽  
Author(s):  
K. T. Bates ◽  
P. L. Falkingham
Keyword(s):  
Body Size ◽  
Feeding Behaviour ◽  
Ontogenetic Change ◽  
Positive Allometry ◽  
Musculoskeletal Models ◽  
Terrestrial Animal ◽  
Body Dynamics ◽  
Mode Of Life ◽  
Scaling Analyses ◽  
Multi Body

Bite mechanics and feeding behaviour in Tyrannosaurus rex are controversial. Some contend that a modest bite mechanically limited T. rex to scavenging, while others argue that high bite forces facilitated a predatory mode of life. We use dynamic musculoskeletal models to simulate maximal biting in T. rex . Models predict that adult T. rex generated sustained bite forces of 35 000–57 000 N at a single posterior tooth, by far the highest bite forces estimated for any terrestrial animal. Scaling analyses suggest that adult T. rex had a strong bite for its body size, and that bite performance increased allometrically during ontogeny. Positive allometry in bite performance during growth may have facilitated an ontogenetic change in feeding behaviour in T. rex , associated with an expansion of prey range in adults to include the largest contemporaneous animals.

Sir Robert Stawell Ball and methodologies of modern screw theory

2002 ◽  
Vol 216 (1) ◽  
pp. 1-11 ◽  
Author(s):  
H Lipkin ◽  
J Duffy
Keyword(s):  
Computational Geometry ◽  
Rigid Body ◽  
Lie Algebra ◽  
Screw Theory ◽  
Mechanical Design ◽  
Ball Screw ◽  
Dual Numbers ◽  
Body Dynamics ◽  
Rigid Body Mechanics ◽  
Multi Body

The theory of screws was largely developed by Sir Robert Stawell Ball over 100 years ago to investigate general problems in rigid body mechanics. Nowadays, screw theory is applied in many different but related forms including dual numbers, Plilcker coordinates and Lie algebra. An overview of these methodologies is presented along with a perspective on Ball. Screw theory has re-emerged after a hiatus to become an important tool in robot mechanics, mechanical design, computational geometry and multi-body dynamics.

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