Multi-body dynamic modelling and simulation of the torsional vibration system of converters based on rigid–flexible coupling

AbstractIn this paper, the multi-body dynamic model of an asymmetric variable sweep wing morphing UAV is built based on Kane’s method. This model describes the UAV’s transient behaviour during morphing process and the dynamic characteristic of the variable sweep wings. An integrated design of trajectory tracking control via constrained backstepping method is presented then. The idea of aircraft roll control through asymmetric wing sweep angle changes rather than traditional aileron is explored and used in the fight control design. The control of variable sweep wings is designed as well based on the presented dynamic model. Command filters are used in the backstepping design procedure to accommodate magnitude, rate and bandwidth constraints on virtual states and actuator signals. Stability of the closed-loop system can be proved in the sense of Lyapunov. Simulation of tracking a desired trajectory which contains two manoeuvres demonstrates the feasibility of the proposed protocol and the morphing wing roll controller.

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A multi-body dynamic study of vibration of a planetary gear train with the planetary bearing fault

Proceedings of the Institution of Mechanical Engineers Part K Journal of Multi-body Dynamics ◽

10.1177/1464419319832485 ◽

2019 ◽

Vol 233 (3) ◽

pp. 677-695 ◽

Cited By ~ 1

Author(s):

Jing Liu ◽

Linfeng Wang ◽

Jinlei Ma ◽

Wennian Yu ◽

Yimin Shao

Keyword(s):

Dynamic Model ◽

Dynamic Modelling ◽

Planetary Gear ◽

Elastic Support ◽

Gear Train ◽

Radial Clearance ◽

Ring Gear ◽

Planetary Gear Train ◽

Multi Body ◽

Body Dynamic

Local faults including pits and spalls in any planet bearing can greatly affect the vibration of the planetary gear train, as well as the elastic support of the ring gear. However, the dynamic modelling methods in previous work can only formulate the local fault and the elastic support of the ring gear independently. To address this issue, a multi-body dynamic model for a planetary gear train with a local fault in the planet bearing and an elastic ring gear foundation are introduced to analyze the effect of local fault on the vibration. The local fault in the planet bearing is modelled as a rectangular one. Both the planet bearings including the radial clearance and ring gear with an elastic foundation are considered in the multi-body dynamic model. The contact stiffnesses and damping coefficients of gears and bearings are calculated by the methods reported in the literature. A Coulomb friction model is adopted to model the frictions between mating components of the system. In order to validate the proposed multi-body dynamic model, its simulation results are directly compared with those from theoretical methods as well as the experimental methods reported in the literature. Moreover, parameter studies are conducted to discuss the effects of local faults in the planet-bearing races, the sun gear speed, and the carrier moment on the vibration of the planetary gear train. The analyzing results of this study can provide some guidance for detection approaches of local faults in the planet bearings of planetary gear trains through vibration analysis.

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A Study on Multi-body Dynamic Modelling and Optimization for Mechanical Quick Closing Valve

MATEC Web of Conferences ◽

10.1051/matecconf/201816703004 ◽

2018 ◽

Vol 167 ◽

pp. 03004

Author(s):

Wang Bo ◽

Li Junyan ◽

Wu Lifang ◽

Chen Xuekai

Keyword(s):

Lagrange Equation ◽

Structural Parameters ◽

Dynamic Modelling ◽

Friction Model ◽

Normal Contact ◽

Control Rod ◽

Multi Body ◽

Off Time ◽

Body Dynamic ◽

Modelling And Optimization

The multi-body dynamic modelling and optimization methods of mechanical quick closing valve are studied in this paper. The Lagrange equation is specified characterizing the closing process. Normal contact force and tangent friction force between the components are obtained by using equivalent spring-damper model and no-linear coulomb friction model. The theoretical result of the valve’s kinematic response is verified by the experiment. In order to analyse the relationship between structural parameters and the closing behaviour intuitively, a single degree of freedom model is provided. It is shown that the mass of the control rod is the key parameter exerting important influence on the cut-off time of the valve. The cut-off time will be shortened by about 1.2ms while the mass of control rod reduces 0.01kg.

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Study the Effect of Torsional Vibration on Valvetrain Dynamic in a Heavy Duty Diesel Engine Using Multi-Body Dynamic

ASME 2009 Internal Combustion Engine Division Fall Technical Conference ◽

10.1115/icef2009-14029 ◽

2009 ◽

Author(s):

Mehdi Mehrgou

Keyword(s):

Diesel Engines ◽

Torsional Vibration ◽

Internal Combustion Engines ◽

Precise Determination ◽

Gear Train ◽

Valve Train ◽

Heavy Duty ◽

Heavy Duty Diesel ◽

Multi Body ◽

Body Dynamic

Today, due to technical, commercial and environmental requirements, internal combustion engines especially heavy duty diesel engines must operate with high cylinder pressures and the components must be optimized for the best performance. Heavy duty diesel engines usually rotate the driven machinery with a large inertia such as generators, or ship propeller. A crankshaft is subjected to periodic dynamic loads; also other inconsistencies could make misfire in engine and because of the torsional vibration in engine, the crankshaft has fluctuating instantaneous speed. Due to the essence of this type of the engine which has heavy parts, beside the robust design of them, and relatively high torques which need to rotate the camshaft, these engines valvetrain normally drive with gears. In consequence the rotating speed of engine crankshaft completely transfer to the camshaft because of high amount of crank train’s inertia in comparison with the valve train and in some cases using the damper for camshaft is required. Modern calculation methods allow for the precise determination of system dynamic and loads. Thus, it is possible to consider design margins that ensure sufficient reliability to avoid undesired dynamic behavior which could lead to structural failures, besides avoiding the components over sizing. In this paper ADAMS\Engine commercial software has been used for simulating the coupled engine cranktrain and valve train subsystems of an engine under development. The engine complete dynamic simulation with Multi-Body Dynamic tool including backlash in gear train and torsionally flexible camshaft, prepare a good model for study the effect of engine cranktrain dynamics on its valvetrain.

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Analysis of Torsional Vibration of Large-Scale Ship Propulsion Shafting

Volume 3: Structures, Safety and Reliability ◽

10.1115/omae2015-42392 ◽

2015 ◽

Author(s):

Weizhong Tan ◽

Cong Zhang ◽

Zhe Tian ◽

Xinping Yan

Keyword(s):

Torsional Vibration ◽

Large Scale ◽

Ship Hull ◽

Dynamic Coupling ◽

The Real ◽

Ship Propulsion ◽

Torsion Vibration ◽

Simulation Results ◽

Multi Body ◽

Body Dynamic

This paper is based on the multi-body dynamic coupling theory and finite element theory. A multi-body dynamic coupling model of the large-scale vessel is built and the torsion vibration characteristics of slow-speed ship propulsion shafting are analyzed. The measurements of shafting torsional vibration in the real ship are compared with the results from the simulation model. Then, the differences between measurements and simulation results are analyzed in multi-orders. The analysis result indicates that the simulation results are almost the same with measurements obtained from the real ship, which verify the correctness and feasibility of the model. At the same time, the influence of ship hull deformation on the torsion vibration of ship propulsion shafting is discussed by Adams/Vibration. The analysis shows that the ship hull deformation could cause the significant increase of torsional vibration of ship propulsion shafting.

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