Analysis of Torsional Vibration of Large-Scale Ship Propulsion Shafting

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.

Multi-Body Dynamic Analysis of Driveline Torsional Vibration for an RWD Vehicle

2014 ◽  
Author(s):  
Yuan feng Xia ◽  
Jian Pang ◽  
Chengtai Hu ◽  
Cui Zhou ◽  
Cong Wu
Keyword(s):  
Dynamic Analysis ◽  
Torsional Vibration ◽  
Multi Body ◽  
Body Dynamic

scholarly journals Automated Linearization of Nonlinear Coupled Differential and Algebraic Equations

1991 ◽  
Author(s):  
Martin J. Vanderploeg ◽  
Jeff D. Trom
Keyword(s):  
Finite Difference ◽  
Dynamic Systems ◽  
Large Scale ◽  
Algebraic Equations ◽  
New Approach ◽  
Large Scale Systems ◽  
Equation Formulation ◽  
Equilibrium Configurations ◽  
Multi Body ◽  
Body Dynamic

Abstract This paper presents a new approach for linearization of large multi-body dynamic systems. The approach uses an analytical differentiation of terms evaluated in a numerical equation formulation. This technique is more efficient than finite difference and eliminates the need to determine finite difference pertubation values. Because the method is based on a relative coordinate formalism, linearizations can be obtained for equilibrium configurations with non-zero Cartesian accelerations. Examples illustrate the accuracy and efficiency of the algorithm, and its ability to compute linearizations for large-scale systems that were previously impossible.

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

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.

Dynamic Interaction Analysis of a 2D Propulsion Shaft-Ship Hull System Subjected by Sea Wave

2014 ◽  
Author(s):  
Zhe Tian ◽  
Xinping Yan ◽  
Zhixiong Li ◽  
Cong Zhang
Keyword(s):  
Large Scale ◽  
Interaction Analysis ◽  
Coupled System ◽  
Ship Hull ◽  
Propulsion System ◽  
Coupling Mechanism ◽  
Sea Waves ◽  
Ship Propulsion ◽  
Large Ship ◽  
Sea Wave

Since there is an evident tendency of development of large scale ships, the interaction between the propulsion shaft and ship hull becomes severe due to the tremendously increased ship size. As a result the reliability of the vessels has been put in an important position by the companies and the governments all over the world. The excited forces caused by severe sea waves have considerable effects on the hull deformation which could have further impact on the shaft propulsion system. This paper aims to investigate the coupling dynamics between the large ship propulsion system and hull subjected by sea wave in 2-dimensional circumstance. To look into the coupling mechanism between the ship propulsion shaft, hull and sea waves, a 2-dimensional novel model of large ship propulsion-hull coupling system is presented in this work to analyze the dynamic interactions of the ship propulsion system and hull. According to the dynamic equations of the coupling model, the dynamical responses of the ship shaft and hull are obtained under different stiffness of the support bearings. The analysis indicates that choosing the suitable stiffness of bearings have an important effect on the coupled system.

scholarly journals A Dynamic Model for Simulating Elephant-Lifting by Using a Tilting Frame

2020 ◽  
Vol 24 (5) ◽  
pp. 195-206
Author(s):  
Komsan Mianpet ◽  
Satjarthip Thusneyapan
Keyword(s):  
Dynamic Model ◽  
Motion Analysis ◽  
Standing Position ◽  
Displacement Velocity ◽  
The Real ◽  
Mechanism Model ◽  
Experimental Ethics ◽  
The Cost ◽  
Multi Body ◽  
Body Dynamic

A rigid multi-body dynamic model of an elephant was developed for motion analysis during tilt-lifting. The elephant lifting to standing position is required by veterinarians to perform surgery and bedsores treatment. The elephant mechanism dynamic model (EMDM) was developed by simplifying the skeleton to simple straight linkages connected by joints. The model consisted of 10 bones and 9 joints. A mechanical harness model (MHM) was developed. Two harnesses were attached to the tilt-frame mechanism model (FMM) and the EMDM; this assembly became the elephant dynamic during tilt-lifting model (EDTM). The developed EDTM permitted us to observe the displacement, velocity, and acceleration responses at any location on the elephant. The model allowed the virtual study of the motion, and avoided the real elephant testing; thus, the cost, time, and resources were reduced and no conflict with the animal experimental ethics. The simulation was found to be a valuable tool for engineers to design a suitable elephant bed. It permitted us to observe the operation, safety, and precaution of the equipment.

Design and Spread Analysis of a New Deployable Bridge Section

2013 ◽  
Vol 639-640 ◽  
pp. 206-210
Author(s):  
Duan Cai Yuan ◽  
Qi Gao Hu ◽  
Guang Xu Sun
Keyword(s):  
Theoretical Analysis ◽  
Maximum Error ◽  
Hydraulic Cylinder ◽  
Adams Software ◽  
Integral Structure ◽  
Simulation Results ◽  
Multi Body ◽  
Spread Analysis ◽  
And Storage ◽  
Body Dynamic

For the volume of the new prefabricated bridge with integral structure is huge and transportation and storage are difficult, scissors mechanism driven by hydraulic cylinder is presented to bridge design. Wth theoretical analysis, the position of the node, velocity and acceleration are analyzed. Using the ADAMS software, the whole model of deployable bridge section is established. The multi-body dynamic simulation of the whole model is studied. The simulation results are compared with those of theoretical analysis. The maximum error of them is 2.26%. The methods and conclusions are available for the design of developable bridge section.

Multi-body dynamic coupling mechanism for generating throwing arm velocity during baseball pitching

2017 ◽  
Vol 54 ◽  
pp. 363-376 ◽  
Author(s):  
Kozo Naito ◽  
Tokio Takagi ◽  
Hideaki Kubota ◽  
Takeo Maruyama
Keyword(s):  
Coupling Mechanism ◽  
Dynamic Coupling ◽  
Multi Body ◽  
Body Dynamic

Factual Power Loss Diminution by Enhanced Frog Leaping Algorithm

2020 ◽  
Vol 3 (2) ◽  
pp. 114-118
Author(s):  
Kanagasabai Lenin
Keyword(s):  
Local Search ◽  
Power Loss ◽  
Reactive Power ◽  
Test System ◽  
Premature Convergence ◽  
Speed Of Convergence ◽  
Real Power ◽  
The Real ◽  
Simulation Results ◽  
Power Problem

This paper proposes Enhanced Frog Leaping Algorithm (EFLA) to solve the optimal reactive power problem. Frog leaping algorithm (FLA) replicates the procedure of frogs passing though the wetland and foraging deeds. Set of virtual frogs alienated into numerous groups known as “memeplexes”. Frog’s position’s turn out to be closer in every memeplex after few optimization runs and certainly, this crisis direct to premature convergence. In the proposed Enhanced Frog Leaping Algorithm (EFLA) the most excellent frog information is used to augment the local search in each memeplex and initiate to the exploration bound acceleration. To advance the speed of convergence two acceleration factors are introduced in the exploration plan formulation. Proposed Enhanced Frog Leaping Algorithm (EFLA) has been tested in standard IEEE 14,300 bus test system and simulation results show the projected algorithm reduced the real power loss considerably.

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