scholarly journals Dynamic modelling and analysis of 3D overhead gantry crane system

2018 ◽  
Vol 7 (3) ◽  
pp. 1257
Author(s):  
Khalil Azha Mohd Annuar ◽  
Nik Azran Ab. Hadi ◽  
Mohamad Haniff Harun ◽  
Mohd Firdaus Mohd Ab. Halim ◽  
Siti Nur Suhaila Mirin ◽  
...  
Keyword(s):  
Linear Model ◽  
Nonlinear Dynamic ◽  
Equations Of Motion ◽  
Dynamic Modelling ◽  
Gantry Crane ◽  
Nonlinear Dynamic Model ◽  
Simulation Results ◽  
And Performance ◽  
Heavy Loads ◽  
Load Swing

The overhead gantry crane systems are extensively used in harbours and factories for transportation of heavy loads. The crane speeding up, required for motion, always induces undesirable load swing. This writings present dynamic modelling of a 3D overhead gantry crane sys-tem based on closed-form equations of motion. By using the Lagrange technique, a 3D overhead gantry crane system nonlinear dynamic model is deriving. Then perform a linearization process to obtain a linear model dynamic system. Finally, simulation results systems re-sponses of the derived nonlinear and linear model are presented showing the accuracy and performance of both model.  

Nonlinear Dynamic Modelling of a Revolute-Prismatic Flexible Composite-Material Robot Arm

1991 ◽  
Vol 113 (4) ◽  
pp. 461-468 ◽  
Author(s):  
F. Gordaninejad ◽  
A. Azhdari ◽  
N. G. Chalhoub
Keyword(s):  
Shear Deformation ◽  
Nonlinear Dynamic ◽  
Fibrous Composite ◽  
Equations Of Motion ◽  
Dynamic Modelling ◽  
Beam Theory ◽  
Rotary Inertia ◽  
Robot Arm ◽  
Nonlinear Dynamic Model ◽  
End Effector

In this work, a nonlinear dynamic model is derived to study the motion of a planar robot arm consisting of one revolute and one prismatic joint. Both links of the arm are considered to be flexible and are assumed to be constructed from either isotropic conventional metallic materials or anisotropic laminated fibrous composite materials. The model is derived based on the Timoshenko beam theory in order to account for the rotary inertia and shear deformation. In addition, a nonlinear strain-displacement field is implemented to consider the large deformation of the arm. The deflections of the links are discretized by using a shear-deformable beam finite element. The governing equations of motion are derived from Hamilton’s principle. The digital simulation studies examine the combined effects of geometric nonlinearity, rotary inertia, and shear deformation on the arm’s end effector displacements. Furthermore, effects of the fiber’s angle and material orthotropy on the end effector displacements and maximum normal bending stress are studied.

Takeoff Analysis and Simulation of a Small Scaled UAV with a Rocket Booster

2011 ◽  
Vol 267 ◽  
pp. 674-682 ◽  
Author(s):  
Bo Liu ◽  
Zhou Fang ◽  
Ping Li ◽  
Chuan Chuan Hao
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Unmanned Aerial Vehicle ◽  
Nonlinear Dynamic ◽  
Total Mass ◽  
Nonlinear Dynamic Model ◽  
Centre Of Gravity ◽  
Acceptable Range ◽  
Aerial Vehicle ◽  
Simulation Results

This paper analyses the takeoff process of a small scaled UAV (unmanned aerial vehicle) with a single rocket booster. Because the thrust provided by the rocket booster is 10 times as large as the thrust provided by the engines, the effects caused by the boosting rocket on total mass, compound centre of gravity and inertia can not be neglected and are all considered. The inertia of the boosting rocket is calculated by the means of finite element method. Based on the analysis, a nonlinear dynamic model of the UAV is built. Several simulations with different takeoff parameters are conducted to test the takeoff performance. By analyzing simulation results, the acceptable range of boosting angle is investigated.

Sliding behavior of high speed ball bearings based on improved nonlinear dynamic model

2021 ◽  
pp. 146441932110430
Author(s):  
Dongsheng Qian ◽  
Xiaotian Xu ◽  
Song Deng ◽  
Shaofeng Jiang ◽  
Lin Hua
Keyword(s):  
Dynamic Model ◽  
Nonlinear Dynamic ◽  
High Speed ◽  
Dynamic Models ◽  
Time Varying ◽  
Ball Bearings ◽  
Nonlinear Dynamic Model ◽  
Dynamic Behaviors ◽  
Low Speeds ◽  
Heavy Loads

To accurately predict the dynamic behaviors of high speed ball bearings, an investigation on the sliding behavior of balls at high and low speeds, and light and heavy loads is necessary. However, existing nonlinear dynamic models fail to consider comprehensively key factors such as asperity and hydrodynamic tractions, time-varying friction coefficient and time-varying lubricant mode. In this work, these influencing factors are integrated into the nonlinear dynamic model to make it suitable for the working conditions of high and low speeds and light and heavy loads. The dynamic analysis provides the relation of angular speeds of balls with spin and sliding at light and heavy loads, also it reveals the number of pure rolling point under the combined effect of differential sliding and spin sliding. Research results provide a reliable mathematical model and theoretical bases for further studying the dynamic behaviors of high speed ball bearings.

Reduced-Order Nonlinear Dynamic Model of Coupled Shaft-Torsional and Blade-Bending Vibrations in Rotors

2000 ◽  
Vol 123 (1) ◽  
pp. 82-88 ◽  
Author(s):  
B. O. Al-Bedoor
Keyword(s):  
Dynamic Model ◽  
Nonlinear Dynamic ◽  
Equations Of Motion ◽  
Small Deformation ◽  
Nonlinear Dynamic Model ◽  
Bending Vibrations ◽  
Reduced Order ◽  
Lagrange’S Equation ◽  
Multibody Dynamic ◽  
Parametric Studies

In this study, a reduced-order nonlinear dynamic model for shaft-disk-blade unit is developed. The multibody dynamic approach with the small deformation theory for both blade-bending and shaft-torsional deformations is adopted. The equations of motion are developed using Lagrange’s equation in conjunction with the assumed modes method (AMM) for approximating the blade transverse deflection. The model showed strong coupling between the blade bending and shaft torsional vibrations in the form of inertial nonlinearity, modal coupling, stiffening, softening, and parametric excitations. The model is suitable for extensive parametric studies for predesign stage purposes as well as for diagnostics of rotor malfunctions, when blade and shaft torsional vibration interaction is suspected.

Dynamic Modelling of CVD for Real-Time Control of Microstructure

1994 ◽  
Vol 363 ◽  
Author(s):  
M.A. Gevelber ◽  
M.T. Quiñones ◽  
M.L. Bufano
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Nonlinear Dynamic ◽  
Control Structure ◽  
Dynamic Modelling ◽  
Chemical Vapor ◽  
Real Time Control ◽  
Nonlinear Dynamic Model ◽  
Time Control ◽  
Insight Into

AbstractA nonlinear dynamic model of the chemical vapor deposition (CVD) process has been developed and analyzed to obtain insight into the design of an appropriate control structure.

Nonlinear dynamic response of reciprocating compressor system with rub-impact fault caused by subsidence

2019 ◽  
Vol 25 (11) ◽  
pp. 1737-1751 ◽  
Author(s):  
Shungen Xiao ◽  
Shulin Liu ◽  
Feng Jiang ◽  
Mengmeng Song ◽  
Shouguo Cheng
Keyword(s):  
Nonlinear Dynamic ◽  
Chaotic Behavior ◽  
Vibration Response ◽  
Maximum Lyapunov Exponent ◽  
Time Varying ◽  
Reciprocating Compressor ◽  
Nonlinear Dynamic Model ◽  
Nonlinear Dynamic Response ◽  
Motion Modes ◽  
Simulation Results

In this paper, a nonlinear dynamic model of the single-stage reciprocating compressor system with a rub-impact fault caused by subsidence is developed, considering the piston rod flexibility. Meanwhile, different rub-impact scenarios of the crosshead including no corner, a single corner, two opposite corners, and two adjacent corners of the crosshead impacting on the slide, are considered in this model. Numerical simulation results show that the subsidence, time-varying load, and piston rod flexibility have significant effects on the vibration response of the reciprocating compressor system with rub-impact, where the larger the subsidence and time-varying load, the more intense the vibration response. Moreover, compared to the rigid piston rod, the flexible piston rod causes the system to generate stronger shock. In the rub-impact, the crosshead appeared in three different motion modes: noncontact; permanent contact; and collision – and most of the collisions occur in the form of two adjacent corners impacting on the slide. In addition, strange attractors are observed in the phase space trajectories, and the existence of chaotic behavior is verified using the Poincaré section method and maximum Lyapunov exponent method.

Investigation of oil-air flow and temperature for high speed ball bearings by combining nonlinear dynamic and CFD models

2021 ◽  
pp. 1-11
Author(s):  
Song Deng ◽  
Guiqiang Zhao ◽  
Dongsheng Qian ◽  
Shaofeng Jiang ◽  
Lin Hua
Keyword(s):  
Nonlinear Dynamic ◽  
High Speed ◽  
Heat Dissipation ◽  
Air Flow ◽  
Engineering Application ◽  
Elastohydrodynamic Lubrication ◽  
Ball Bearings ◽  
Nonlinear Dynamic Model ◽  
Cfd Models ◽  
Heavy Loads

Abstract An improved nonlinear dynamic model of high speed ball bearings with elastohydrodynamic lubrication (EHL) is adopted to predict the movements of balls and power loss of ball bearings for defining the boundary conditions of computational fluid dynamics (CFD) model. Then, this method of combining nonlinear dynamic and CFD models is are validated through the experimental verification. Subsequently, oil-air flow and temperature distribution inside the bearing chamber are studied at low and high speeds, and light and heavy loads. The effect of nozzle's position on the formation of oil film and heat dissipation is revealed under combined loads. The research results provide a theoretical basis for engineering application of high speed rolling bearings.

Nonlinear Dynamic Modelling of Gear-Shaft-Disk-Bearing Systems Using Finite Elements and Describing Functions

2003 ◽  
Author(s):  
Rafiq Maliha ◽  
Can U. Dog˘ruer ◽  
H. Nevzat O¨zgu¨ven
Keyword(s):  
Dynamic Model ◽  
Nonlinear Dynamic ◽  
Dynamic Modelling ◽  
Spur Gear ◽  
Discrete Models ◽  
Nonlinear Dynamic Model ◽  
Disk System ◽  
Describing Functions ◽  
Gear Mesh ◽  
System A

This study presents a new nonlinear dynamic model for a gear-shaft-disk-bearing system. A nonlinear dynamic model of a spur gear pair is coupled with linear finite element models of shafts carrying them, and with discrete models of bearings and disks. The nonlinear elasticity term resulting from backlash is expressed by a describing function, and a method developed in previous studies to determine the harmonic responses of nonlinear multi degree of freedom systems is employed for the solution. The code developed, Nonlinear Geared Rotor Dynamics (NLGRD), combines the versatility of modeling a shaft-bearing-disk system that can have any configuration, with the accuracy of an advanced nonlinear gear mesh interface model. Thus any single stage gear mesh configuration can be modeled easily and accurately. NLGRD is capable of calculating dynamic gear loads, dynamic bearing forces, bearing displacements and making modal analysis of the corresponding linear system. Theoretical results obtained by NLGRD are compared with the experimental data available in literature.

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