Abstract. 1 Introduction
|
|
- Camilla Cain
- 5 years ago
- Views:
Transcription
1 Consideration of medium-speed four-stroke engines in ship vibration analyses I. Asmussen, A. Muller-Schmerl GermanischerLloyd, P.O. Box , 20416Hamburg, Germany Abstract Vibration problems were recently observed on some ships equipped with medium-speed diesel engines. Measurements revealed in these cases resonance condition between ignition frequency and H-type vibrations of the engines. As a consequence the excitation forces transmitted from the engines to the foundations were drastically magnified. A procedure is described how the natural frequency of the corresponding H-type modes can be predicted at the design stage. The procedure is demonstrated on the example of three vessels. The results obtained theoretically are verified by measurements. Generally, it was found that the calculated natural frequencies of the H-modes are in very good agreement with the measured values. It is shown that reliable results can only be obtained by considering the stiffness of the engine housing. Following this approach a tool has been developed to predict the natural frequency of the H- type mode shape of a medium-speed engine with a high degree of accuracy. In case of danger of resonance, proposals can be given to detune the system, either by mounting the engine full- or semi-resiliently, or by changing the stiffness of the foundation. 1 Introduction As a result of the steady increase in mean effective and firing pressures of medium-speed four-stroke engines, as well as of optimized structures vibration problems have been observed during operation. In these cases measurements revealed resonance proximity between the firing frequency and the transverse vibration mode of the engine on its foundation, the so-called H-type vibration. Despite the fact that this resonance results in forces introduced into the hull
2 368 Marine Technology and Transportation being significantly magnified dynamically, present dimensioning practice is restricted to avoiding resonance of local structures. As it is extremely costly to change the vibration behaviour of the engine/foundation once the vessel is in service, a procedure has been developed for assessing the risk of resonance at the design stage using the finite element (FE) technique. During the past few years comprehensive research work has been carried out with the aim to realistically simulating the introduction of forces into the hull, by integrating the engine into the FE model of the hull. This has, however, been done for slow-speed two-stroke engines only [1] - [3]. 2 Typical vibration modes of medium-speed engines The combustion forces occurring during ignition play a dominant role as excitation source coming from medium-speed four-stroke engines. Due to these forces, transferred through the crank gear, transversal and vertical forces act on the engine structure and excite the typical engine vibration modes: the transverse vibration about the longitudinal axis (H-type mode), the torsional vibration about the vertical axis (X-type mode) as well as the longitudinal vibration about the transversal axis (L-type mode). While the longitudinal vibration may be excited by vertical forces, the H-type and X-type vibrations are predominantly caused by the transverse guide forces. Fig. 1 shows schematically the combustion forces resulting in the typical engine excitation moments. guide forces H-moment guide forces X-moment vertical forces L-moment Figure 1: Excitation forces and moments of engines, It is of particular significance that the H-moment occurring at the firing frequency is an external moment, which is fully - or dynamically magnified - introduced into the foundation. The X- and L-moments, on the other hand, are internal moments, which act externally only through the deformation of the engine casing. Contrary to slow-speed engines severe L-type and X-type excitations occur very rarely with medium-speed engines. Therefore, H-type vibrations are of particular interest for this type of engine.
3 Marine Technology and Transportation Procedure for assessing the H-type transverse vibration mode of the engine/foundation system In view of the large number of influence parameters it is not possible to offer a solution in form of estimating formulae. As outlined below, it is also impossible to consider the engine or the ship's foundation as isolated systems, i.e. to neglect their interactions. Therefore, a practical procedure is described to predict the transverse natural frequency of the engine/foundation with the aid of a simple, three-dimensional FE model. The FE model as well as the calculated H-mode vibration of the engine/foundation of one of the three ships, which were selected to demonstrate the procedure here are shown in Fig. 2. Figure 2: FE model and calculated H-type mode of the engine/foundation. 3.1 Engine idealization For the idealization of the engine all components characterizing the global stiffness are modelled by plane stress elements of equivalent stiffness and mass distribution. Components, which have an insignificant effect upon the overall engine stiffness are only accounted for with respect to their masses. The masses are partly realized by auxiliary truss elements on the engine's periphery or by increasing the density of the surrounding elements. A realistic idealization of the complicated cast housing, an exact realization of the mass moments of inertia as well as a correct modelling of the engine width in conformity with the foundation are of particular significance with regard to the accuracy of the results obtained. 3.2 Foundation idealization By numerous variant calculations it has been possible to verify that, normally, only the double bottom in way of the engine room has to be idealized. It is sufficient to consider the essential structures, such as top plate, inner bottom, shell,
4 370 Marine Technology and Transportation longitudinal and transverse girders etc.. In order to estimate the effect of the adjacent structures, the model is rigidly supported at the forward and aft engine room bulkheads in the global directions as well as vertically at the points of connection of the shell and the frames. The masses of tank contents and hydrodynamic masses are in most cases negligible. It is, however, emphasized that the ship model simplifications described are admissible only, if it is ensured that the natural frequency of the basic double bottom vibration mode occurs considerably above the H-type eigenfrequency. 4 Application of the procedure to three example ships Following the principles as outlined, corresponding analyses were performed for three example vessels and compared with measurements. The ships were chosen such as to clearly illustrate the effect of different engine and foundation structures upon the H-type frequencies. In this context, it has to be noted that ships 2 and 3 are equipped with the same engine, i.e. the effect of the foundation structure upon the frequency will become particularly obvious. 4.1 Calculation of natural vibrations In a first step the H-type transverse mode of the engines supported on an infinitely rigid foundation was calculated: Table 1: H-Type eigenfrequencies of engines with infinitely rigid foundation eigenfrequency (cps) engine 1 engine Using a very detailed FE model, the manufacturer of engine 1 calculated the corresponding mode at 41 cps also. It becomes obvious that the simple engine model is well suited to calculate the H-type transverse eigenfrequency, but offers only limited information on the exact mode shape because of simplifications with regard to modelling of partial vibration systems such as the turbocharger, for instance. In a next step the H-type transverse eigenfrequencies of the engines as mounted on the hull foundations were calculated, see results in table 2. A calculated H-type vibration mode of one example ship can be seen in Fig. 2. Table 2: Measured and calculated H-type transverse eigenfrequencies ship 1 ship 2 ship 3 measured eigenfrequency (cps) calculated eigenfrequency (cps)
5 Marine Technology and Transportation 371 An important factor in the assessment of new procedures is the verification of the calculated values by measurements. The left side of table 2 gives the eigenfrequencies, determined by extensive measurements conducted by the engine manufacturer and Germanischer Lloyd. Fig. 3 shows the transverse amplitude measured on the upper edge of the cylinder crankcase as a function of the firing frequency. The resonance frequency obtained from the calculation is drawn into the measured response curve, showing good agreement frequency [cps] Figure 3: Measured response function at ignition frequency. A notable fact, in view of the very similar vibration behaviour of the engines with infinitely rigid support, see table 1, is the remarkable frequency difference of the engines support on foundations of finite stiffness (25 to 34 cps). This is due to the different foundation stiffnesses. The pronounced frequency decrease in case of flexible foundations clearly shows the significance of the integrated consideration of engine and foundation. With respect to the engine stiffness, the transverse vibration behaviour proves to be very sensitive as well. Variant calculations for the three ships with the engine being modelled as a rigid body, showed an increase in frequencies in the range of 20 % to 70 %, depending on the foundation stiffness. A simplified idealization of the engine as an infmitly rigid body is therefore not possible. 4.2 Calculation of forced vibrations An attempt was also made to calculate the response of the engine using the mode superposition method [4]. The evaluation of measured resonance curves, see fig. 3 for example, made it possible to estimate a damping factor. For the transverse bending vibration of the main engine a modal damping of 6 % could be assessed following the theory given in [5]. The response (velocity peak
6 372 Marine Technology and Transportation values) was determined on the upper edge of the crankcase at mid engine due to excitation by the H-moment. Table 3: Comparison of calculated and measured amplitudes ship 1 ship 2 ship 3 \ velocity amp itude (mm/s) in rescmance at IVICR calculated measured 11 5 calculated measured The fact that the largest deviations occur at the resonance frequency indicates that the damping factor used in the calculation was somewhat too small. However, the results do show that the procedure described is suitable to also estimate the magnitude of engine vibrations excited at firing frequency. 5 Countermeasures in case of resonance proximity A comparison of the calculated eigenfrequency with the firing frequency reveals a possible risk of resonance. In resonance proximity the forces introduced into the foundation and thus into the ship may be magnified dynamically 6 to 9 times. In case of an excitation frequency/eigenfrequency ratio of 0.7 < fexc/^eig. < 1.3 it is, therefore, recommended to initiate countermeasures in order to detune the engine/foundation system. Possible measures with respect to the recommended frequency ranges of a low-vibration design are shown schematically in Fig. 4. Here the transfer function of a one degree of freedom (H-type motion of engine) system is plotted. 05 to X undercritical design engine rigidly supported on stiff foundation overcritical design enginerigidlysupported on weak foundation or engine mounted semi-resiliently engine mounted full-resiliently 1 1/2 excitation frequency / eigenfrequency Figure 4: Possible countermeasures to detune engine/foundation vibrations.
7 Marine Technology and Transportation 373 The individual measures can be: 5.1 Varying the foundation stiffness Frequency variation in case of a rigidly mounted engine can possibly be achieved by modifying the foundation design. An effective undercritical design of a foundation realizing a safety margin of 30 % requires high, stiff foundations. It appears appropriate only for engines with relatively low firing frequencies. For engines with higher firing frequencies an overcritical design may be more appropriate. The foundations will then be of a more elastic construction, so that after passing the resonance a condition with low amplitudes will occur. However, this method has also its limitations. Apart from possible strength problems and classification requirements to be observed, it has to be ensured that the next higher vibration modes will not enter into the excitation frequency range. 5.2 Engine mounted full-resiliently An alternative method is to support the main engine elastically on spring elements, with a view to significantly detune the system of engine and foundation. A frequency ratio fexcaeig. ^ the range between 2 and 4 is to be aimed at, so that the magnitude of the forces introduced into the ship will fall drastically below the static values (vibration isolation). However, the amplitudes at the engine may increase considerably, so that the connections to other components have to be installed elastically. 5.3 Engine mounted semi-resiliently Another alternative is to use a semi-resilient support of the engine [6], see Fig. 5. Compared with the a full-resilient support, it is not so effective, but less costly. By fitting semi-elastic elements it is possible to decrease the natural frequency of the H-mode and hence to reduce the forces transferred to the foundation in the order of the static values. Elastic connections are, as a rule, generally not necessary. Figure 5: Principle of a semi-resilient mounting. / engine bedplate semi-resilient element shock fast top plate ship's foundation The countermeasures finally to be chosen for detuning the vibration system depend on the individual case.
8 374 Marine Technology and Transportation It is pointed out that the procedure to calculate the natural frequency of the H-mode described can be applied for full-resiliently and semi-resiliently mounted systems as well. For these cases the stiffness effects of the elastic or of the semi-elastic supporting elements have to be taken into account. In the FE models the supporting elements were simulated by beam elements with corresponding vertical and horizontal stiffness values. For the calculation of the vibrations of a full-resiliently supported engine the foundation normally need not be included in the model. Due to the considerable difference in stiffness of the foundation and the elastic supporting elements, the elasticity of the foundation can be neglected. The stiffness ratio between foundation and elastic elements should, however, be at least 10. For the calculation of semi-elastically supported engines this simplification is not possible. With reference to ship 1 as described in chapter 2.1, two sister ships were provided with semi-resilient supports (ship la with non-optimized, ship Ib with optimized elements). Both versions were calculated with the aid of the procedure described. A comparison of the calculated H-type eigenfrequencies with values obtained by measurements performed by the engine manufacturer confirms the reliability of the method. Table 4: Measured and calculated H-type transverse eigenfrequencies for semi-resiliently supported engines. ship la ship Ib measured frequency (Hz) calculated frequency (Hz) References 1. Mumm, H. & Asmussen, I. Simulation of low-speed main engine excitation forces in global vibration analyses, Proceedings of the International Conference on Noise & Vibration in the Marine Environment, London, U.K., Meinke, K.-D. Qualitative analysis of the coupled vibrations of main engine and ship hull, Schiffbauforschung 26, 1987 (in German). 3. Donath, G. & Bryndum, L. Vibrations onboard ships induced by the propulsion plant, Handbuch der Werften, Vol. XIX, 1988 (in German). 4. Clough, R. & Penzien, J. Dynamic of Structures, Mac Graw Hill, Nashif, A.D., Jones, D.I.G., Henderson, J.P. Vibration Damping, John Wiley & Sons, Lausch, W. Semi-resilient engine mounting system from MAN B&W, Diesel Gas Turbine Worldwide, U.S.A., 1991.
Analysis on propulsion shafting coupled torsional-longitudinal vibration under different applied loads
Analysis on propulsion shafting coupled torsional-longitudinal vibration under different applied loads Qianwen HUANG 1 ; Jia LIU 1 ; Cong ZHANG 1,2 ; inping YAN 1,2 1 Reliability Engineering Institute,
More informationShip structure dynamic analysis - effects of made assumptions on computation results
Ship structure dynamic analysis - effects of made assumptions on computation results Lech Murawski Centrum Techniki Okrętowej S. A. (Ship Design and Research Centre) ABSTRACT The paper presents identification
More informationROLLER BEARING FAILURES IN REDUCTION GEAR CAUSED BY INADEQUATE DAMPING BY ELASTIC COUPLINGS FOR LOW ORDER EXCITATIONS
ROLLER BEARIG FAILURES I REDUCTIO GEAR CAUSED BY IADEQUATE DAMPIG BY ELASTIC COUPLIGS FOR LOW ORDER EXCITATIOS ~by Herbert Roeser, Trans Marine Propulsion Systems, Inc. Seattle Flexible couplings provide
More informationPLEASURE VESSEL VIBRATION AND NOISE FINITE ELEMENT ANALYSIS
PLEASURE VESSEL VIBRATION AND NOISE FINITE ELEMENT ANALYSIS 1 Macchiavello, Sergio *, 2 Tonelli, Angelo 1 D Appolonia S.p.A., Italy, 2 Rina Services S.p.A., Italy KEYWORDS pleasure vessel, vibration analysis,
More informationStructural Dynamics Lecture 2. Outline of Lecture 2. Single-Degree-of-Freedom Systems (cont.)
Outline of Single-Degree-of-Freedom Systems (cont.) Linear Viscous Damped Eigenvibrations. Logarithmic decrement. Response to Harmonic and Periodic Loads. 1 Single-Degreee-of-Freedom Systems (cont.). Linear
More informationAalto University School of Engineering
Aalto University School of Engineering Kul-24.4120 Ship Structural Design (P) Lecture 8 - Local and Global Vibratory Response Kul-24.4120 Ship Structures Response Lecture 5: Tertiary Response: Bending
More informationASSESSMENT OF STRESS CONCENTRATIONS IN LARGE CONTAINER SHIPS USING BEAM HYDROELASTIC MODEL
ASSESSMENT OF STRESS CONCENTRATIONS IN LARGE CONTAINER SHIPS USING BEAM HYDROELASTIC MODEL Ivo Senjanović, Nikola Vladimir Faculty of Mechanical Engineering and Naval Architecture, University of Zagreb,
More informationDynamics of Machinery
Dynamics of Machinery Two Mark Questions & Answers Varun B Page 1 Force Analysis 1. Define inertia force. Inertia force is an imaginary force, which when acts upon a rigid body, brings it to an equilibrium
More informationIntroduction to Continuous Systems. Continuous Systems. Strings, Torsional Rods and Beams.
Outline of Continuous Systems. Introduction to Continuous Systems. Continuous Systems. Strings, Torsional Rods and Beams. Vibrations of Flexible Strings. Torsional Vibration of Rods. Bernoulli-Euler Beams.
More informationOn the Dynamic Behaviors of Large Vessels Propulsion System with Hull Excitations
On the Dynamic Behaviors of Large Vessels Propulsion System with Hull Excitations Zhe Tian 1,2, Cong Zhang 1, Xinping Yan 1, Yeping Xiong 2 1. School of Energy and Power Engineering Wuhan University of
More informationThis equation of motion may be solved either by differential equation method or by graphical method as discussed below:
2.15. Frequency of Under Damped Forced Vibrations Consider a system consisting of spring, mass and damper as shown in Fig. 22. Let the system is acted upon by an external periodic (i.e. simple harmonic)
More informationVIBRATION ANALYSIS IN SHIP STRUCTURES BY FINITE ELEMENT METHOD
Proceedings of COBEM 2007 Copyright 2007 by ABCM 19th International Congress of Mechanical Engineering November 5-9, 2007, Brasília, DF VIBRATION ANALYSIS IN SHIP STRUCTURES BY FINITE ELEMENT METHOD Luiz
More informationAnalysis of shock force measurements for the model based dynamic calibration
8 th Worshop on Analysis of Dynamic Measurements May 5-6, 4 Turin Analysis of shoc force measurements for the model based dynamic calibration Michael Kobusch, Sascha Eichstädt, Leonard Klaus, and Thomas
More informationEMA 545 Final Exam - Prof. M. S. Allen Spring 2011
EMA 545 Final Exam - Prof. M. S. Allen Spring 2011 Honor Pledge: On my honor, I pledge that this exam represents my own work, and that I have neither given nor received inappropriate aid in the preparation
More informationStructural Dynamics Lecture 4. Outline of Lecture 4. Multi-Degree-of-Freedom Systems. Formulation of Equations of Motions. Undamped Eigenvibrations.
Outline of Multi-Degree-of-Freedom Systems Formulation of Equations of Motions. Newton s 2 nd Law Applied to Free Masses. D Alembert s Principle. Basic Equations of Motion for Forced Vibrations of Linear
More informationModelling of lateral-torsional vibrations of the crank system with a damper of vibrations
Modelling of lateral-torsional vibrations of the crank system with a damper of vibrations Bogumil Chiliński 1, Maciej Zawisza 2 Warsaw University of Technology, Institute of Machine Design Fundamentals,
More informationRules for Classification and Construction Analysis Techniques
V Rules for Classification and Construction Analysis Techniques 1 Hull Structural Design Analyses 2 Guidelines for Fatigue Strength Analyses of Ship Structures Edition 2004 The following Guidelines come
More informationTable of Contents. Preface... 13
Table of Contents Preface... 13 Chapter 1. Vibrations of Continuous Elastic Solid Media... 17 1.1. Objective of the chapter... 17 1.2. Equations of motion and boundary conditions of continuous media...
More informationFORMULA FOR FORCED VIBRATION ANALYSIS OF STRUCTURES USING STATIC FACTORED RESPONSE AS EQUIVALENT DYNAMIC RESPONSE
FORMULA FOR FORCED VIBRATION ANALYSIS OF STRUCTURES USING STATIC FACTORED RESPONSE AS EQUIVALENT DYNAMIC RESPONSE ABSTRACT By G. C. Ezeokpube, M. Eng. Department of Civil Engineering Anambra State University,
More informationDynamic behavior of turbine foundation considering full interaction among facility, structure and soil
Dynamic behavior of turbine foundation considering full interaction among facility, structure and soil Fang Ming Scholl of Civil Engineering, Harbin Institute of Technology, China Wang Tao Institute of
More informationL13 Structural Engineering Laboratory
LABORATORY PLANNING GUIDE L13 Structural Engineering Laboratory Content Covered subjects according to the curriculum of Structural Engineering... 2 Main concept... 4 Initial training provided for laboratory
More informationStructural Dynamics Lecture Eleven: Dynamic Response of MDOF Systems: (Chapter 11) By: H. Ahmadian
Structural Dynamics Lecture Eleven: Dynamic Response of MDOF Systems: (Chapter 11) By: H. Ahmadian ahmadian@iust.ac.ir Dynamic Response of MDOF Systems: Mode-Superposition Method Mode-Superposition Method:
More informationThe Impact of High-Frequency Vibration on the Performance of Railway Fastening Systems
The Impact of High-Frequency Vibration on the Performance of Railway Fastening Systems Departement of Civil, Geo and Environmental Engineering Chair of Road, Railway and Airfield Construction Maximilian
More informationExperimental studies of springing and whipping of container vessels
Experimental studies of springing and whipping of container vessels Ole Andreas Hermundstad CeSOS Highlights and AMOS Visions Conference 27-29th May 2013 in Trondheim Outline Background and motivation
More informationD : SOLID MECHANICS. Q. 1 Q. 9 carry one mark each. Q.1 Find the force (in kn) in the member BH of the truss shown.
D : SOLID MECHANICS Q. 1 Q. 9 carry one mark each. Q.1 Find the force (in kn) in the member BH of the truss shown. Q.2 Consider the forces of magnitude F acting on the sides of the regular hexagon having
More informationHull loads and response, hydroelasticity
Transactions on the Built Environment vol 1, 1993 WIT Press, www.witpress.com, ISSN 1743-3509 Hull loads and response, hydroelasticity effects on fast monohulls E. Jullumstr0 & J.V. Aarsnes Division of
More informationTHE NEW 1.1 MN m TORQUE STANDARD MACHINE OF THE PTB BRAUNSCHWEIG/GERMANY
THE NEW 1.1 MN m TORQUE STANDARD MACHINE OF THE PTB BRAUNSCHWEIG/GERMANY D. Peschel 1, D. Mauersberger 1, D. Schwind 2, U. Kolwinski 2 1 Solid mechanics department, PTB, Germany 2 Gassmann Theiss Messtechnik
More informationModal Analysis: What it is and is not Gerrit Visser
Modal Analysis: What it is and is not Gerrit Visser What is a Modal Analysis? What answers do we get out of it? How is it useful? What does it not tell us? In this article, we ll discuss where a modal
More informationDimensions of propulsion shafts and their permissible torsional vibration stresses
(Feb 2005) (orr.1 Mar 2012) (orr.2 Nov 2012) Dimensions of propulsion shafts and their permissible torsional vibration stresses.1 Scope This UR applies to propulsion shafts such as intermediate and propeller
More informationMASS LOADING EFFECTS FOR HEAVY EQUIPMENT AND PAYLOADS Revision F
MASS LOADING EFFECTS FOR HEAVY EQUIPMENT AND PAYLOADS Revision F By Tom Irvine Email: tomirvine@aol.com May 19, 2011 Introduction Consider a launch vehicle with a payload. Intuitively, a realistic payload
More informationPLATE GIRDERS II. Load. Web plate Welds A Longitudinal elevation. Fig. 1 A typical Plate Girder
16 PLATE GIRDERS II 1.0 INTRODUCTION This chapter describes the current practice for the design of plate girders adopting meaningful simplifications of the equations derived in the chapter on Plate Girders
More informationUNIT-I (FORCE ANALYSIS)
DHANALAKSHMI SRINIVASAN INSTITUTE OF RESEACH AND TECHNOLOGY DEPARTMENT OF MECHANICAL ENGINEERING QUESTION BANK ME2302 DYNAMICS OF MACHINERY III YEAR/ V SEMESTER UNIT-I (FORCE ANALYSIS) PART-A (2 marks)
More informationStructural intensity analysis of a large container carrier under harmonic excitations of propulsion system
Inter J Nav Archit Oc Engng (2010) 2:87~95 DOI 10.3744/JNAOE.2010.2.2.087 Structural intensity analysis of a large container carrier under harmonic excitations of propulsion system Dae-Seung Cho 1, Kyung-Soo
More informationCork Institute of Technology. Summer 2007 Mechanics of Machines (Time: 3 Hours)
Cork Institute of Technology Bachelor of Engineering (Honours) in Mechanical Engineering- Award Instructions Answer FOUR questions. All questions carry equal marks. (NFQ Level 8) Summer 2007 Mechanics
More informationNoise prediction of large ship 6700PCTC using EFEA-SEA hybrid technique
Noise prediction of large ship 6700PCTC using EFEA-SEA hybrid technique Xinwei ZHANG 1 ; Shawn WANG 2 ; Jinxiang PANG 3 1 SDARI, China 2 Microcomputing LLC, USA 3 PROSYNX Technology Inc, China ABSTRACT
More informationRULES PUBLICATION NO. 17/P ZONE STRENGTH ANALYSIS OF HULL STRUCTURE OF ROLL ON/ROLL OFF SHIP
RULES PUBLICATION NO. 17/P ZONE STRENGTH ANALYSIS OF HULL STRUCTURE OF ROLL ON/ROLL OFF SHIP 1995 Publications P (Additional Rule Requirements), issued by Polski Rejestr Statków, complete or extend the
More informationNONLINEAR CHARACTERISTICS OF THE PILE-SOIL SYSTEM UNDER VERTICAL VIBRATION
IGC 2009, Guntur, INDIA NONLINEAR CHARACTERISTICS OF THE PILE-SOIL SYSTEM UNDER VERTICAL VIBRATION B. Manna Lecturer, Civil Engineering Department, National Institute of Technology, Rourkela 769008, India.
More informationStudy on Motions of a Floating Body under Composite External Loads
137 Study on Motions of a Floating Body under Composite External Loads by Kunihiro Ikegami*, Member Masami Matsuura*, Member Summary In the field of marine engineering, various types of floating bodies
More informationMitigation of Diesel Generator Vibrations in Nuclear Applications Antti Kangasperko. FSD3020xxx-x_01-00
Mitigation of Diesel Generator Vibrations in Nuclear Applications Antti Kangasperko FSD3020xxx-x_01-00 1 Content Introduction Vibration problems in EDGs Sources of excitation 2 Introduction Goal of this
More informationCOUPLED USE OF FEA AND EMA FOR THE INVESTIGATION OF DYNAMIC BEHAVIOUR OF AN INJECTION PUMP
COUPLED USE OF FEA AND EMA FOR THE INVESTIGATION OF DYNAMIC BEHAVIOUR OF AN INJECTION PUMP Yasar Deger Wolfram Lienau Peter Sandford Sulzer Markets & Sulzer Pumps Ltd Sulzer Pumps (UK) Ltd Technology Ltd
More informationINELASTIC RESPONSES OF LONG BRIDGES TO ASYNCHRONOUS SEISMIC INPUTS
13 th World Conference on Earthquake Engineering Vancouver, B.C., Canada August 1-6, 24 Paper No. 638 INELASTIC RESPONSES OF LONG BRIDGES TO ASYNCHRONOUS SEISMIC INPUTS Jiachen WANG 1, Athol CARR 1, Nigel
More informationD : SOLID MECHANICS. Q. 1 Q. 9 carry one mark each.
GTE 2016 Q. 1 Q. 9 carry one mark each. D : SOLID MECHNICS Q.1 single degree of freedom vibrating system has mass of 5 kg, stiffness of 500 N/m and damping coefficient of 100 N-s/m. To make the system
More informationEXPERIMENTAL INVESTIGATION OF THE EFFECTS OF TORSIONAL EXCITATION OF VARIABLE INERTIA EFFECTS IN A MULTI-CYLINDER RECIPROCATING ENGINE
International Journal of Mechanical Engineering and Technology (IJMET) Volume 6, Issue 8, Aug 2015, pp. 59-69, Article ID: IJMET_06_08_006 Available online at http://www.iaeme.com/ijmet/issues.asp?jtypeijmet&vtype=6&itype=8
More informationEXPERIMENTAL MODAL ANALYSIS OF A SCALED CAR BODY FOR METRO VEHICLES
EXPERIMENTAL MODAL ANALYSIS OF A SCALED CAR BODY FOR METRO VEHICLES S. Popprath 1, C. Benatzky 2, C. Bilik 2, M. Kozek 2, A. Stribersky 3 and J. Wassermann 1 1 Institute of Mechanics and Mechatronics,
More informationFLEXIBILITY METHOD FOR INDETERMINATE FRAMES
UNIT - I FLEXIBILITY METHOD FOR INDETERMINATE FRAMES 1. What is meant by indeterminate structures? Structures that do not satisfy the conditions of equilibrium are called indeterminate structure. These
More informationStochastic Dynamics of SDOF Systems (cont.).
Outline of Stochastic Dynamics of SDOF Systems (cont.). Weakly Stationary Response Processes. Equivalent White Noise Approximations. Gaussian Response Processes as Conditional Normal Distributions. Stochastic
More informationLongitudinal strength standard
(1989) (Rev. 1 199) (Rev. Nov. 001) Longitudinal strength standard.1 Application This requirement applies only to steel ships of length 90 m and greater in unrestricted service. For ships having one or
More informationVibration Dynamics and Control
Giancarlo Genta Vibration Dynamics and Control Spri ringer Contents Series Preface Preface Symbols vii ix xxi Introduction 1 I Dynamics of Linear, Time Invariant, Systems 23 1 Conservative Discrete Vibrating
More informationAEROELASTICITY IN AXIAL FLOW TURBOMACHINES
von Karman Institute for Fluid Dynamics Lecture Series Programme 1998-99 AEROELASTICITY IN AXIAL FLOW TURBOMACHINES May 3-7, 1999 Rhode-Saint- Genèse Belgium STRUCTURAL DYNAMICS: BASICS OF DISK AND BLADE
More informationSOLUTION (17.3) Known: A simply supported steel shaft is connected to an electric motor with a flexible coupling.
SOLUTION (17.3) Known: A simply supported steel shaft is connected to an electric motor with a flexible coupling. Find: Determine the value of the critical speed of rotation for the shaft. Schematic and
More informationIntroduction to structural dynamics
Introduction to structural dynamics p n m n u n p n-1 p 3... m n-1 m 3... u n-1 u 3 k 1 c 1 u 1 u 2 k 2 m p 1 1 c 2 m2 p 2 k n c n m n u n p n m 2 p 2 u 2 m 1 p 1 u 1 Static vs dynamic analysis Static
More informationChapter 4 Analysis of a cantilever
Chapter 4 Analysis of a cantilever Before a complex structure is studied performing a seismic analysis, the behaviour of simpler ones should be fully understood. To achieve this knowledge we will start
More information3D Finite Element Modeling and Vibration Analysis of Gas Turbine Structural Elements
3D Finite Element Modeling and Vibration Analysis of Gas Turbine Structural Elements Alexey I. Borovkov Igor A. Artamonov Computational Mechanics Laboratory, St.Petersburg State Polytechnical University,
More informationCOPPER FOR BUSBARS CHAPTER 4: SHORT-CIRCUIT EFFECTS
European Copper Institute COPPER FOR BUSBARS CHAPTER 4: SHORT-CIRCUIT EFFECTS David Chapman August 2011 ECI Available from www.leonardo-energy.org Document Issue Control Sheet Document Title: Publication
More informationSHAKING TABLE TEST OF STEEL FRAME STRUCTURES SUBJECTED TO NEAR-FAULT GROUND MOTIONS
3 th World Conference on Earthquake Engineering Vancouver, B.C., Canada August -6, 24 Paper No. 354 SHAKING TABLE TEST OF STEEL FRAME STRUCTURES SUBJECTED TO NEAR-FAULT GROUND MOTIONS In-Kil Choi, Young-Sun
More informationDynamic Analysis on Vibration Isolation of Hypersonic Vehicle Internal Systems
International Journal of Engineering Research and Technology. ISSN 0974-3154 Volume 6, Number 1 (2013), pp. 55-60 International Research Publication House http://www.irphouse.com Dynamic Analysis on Vibration
More informationChapter 23: Principles of Passive Vibration Control: Design of absorber
Chapter 23: Principles of Passive Vibration Control: Design of absorber INTRODUCTION The term 'vibration absorber' is used for passive devices attached to the vibrating structure. Such devices are made
More informationVerification of assumptions in dynamics of lattice structures
Verification of assumptions in dynamics of lattice structures B.Błachowski and W.Gutkowski Warsaw, Poland 37th SOLD MECHANCS CONFERENCE, Warsaw, Poland September 6 1, 21 Outline of presentation 1. Motivation
More informationEffects of mass distribution and buoyancy on the sound radiation of a fluid loaded cylinder
Effects of mass distribution and buoyancy on the sound radiation of a fluid loaded cylinder Hongjian Wu, Herwig Peters, Roger Kinns and Nicole Kessissoglou School of Mechanical and Manufacturing, University
More informationFeasibility of dynamic test methods in classification of damaged bridges
Feasibility of dynamic test methods in classification of damaged bridges Flavio Galanti, PhD, MSc., Felieke van Duin, MSc. TNO Built Environment and Geosciences, P.O. Box 49, 26 AA, Delft, The Netherlands.
More informationPROPELLER INDUCED STRUCTURAL VIBRATION THROUGH THE THRUST BEARING
PROPELLER INDUCED TRUCTURAL VIBRATION THROUGH THE THRUT BEARING Jie Pan, Nabil Farag, Terry Lin and Ross Juniper* DEPARTMENT OF MECHANICAL AND MATERIAL ENGINEERING THE UNIVERITY OF WETERN AUTRALIA 35 TIRLING
More informationCOPYRIGHTED MATERIAL. Index
Index A Admissible function, 163 Amplification factor, 36 Amplitude, 1, 22 Amplitude-modulated carrier, 630 Amplitude ratio, 36 Antinodes, 612 Approximate analytical methods, 647 Assumed modes method,
More informationCALCULATION OF TORSIONAL VIBRATION RESPONSES IN PROPULSION SHAFTING SYSTEM CAUSED BY ICE IMPACTS
CALCULATION OF TORSIONAL VIBRATION RESPONSES IN PROPULSION SHAFTING SYSTEM CAUSED BY ICE IMPACTS Yuriy A. Batrak *1, Anatoliy M. Serdjuchenko 2 and Alexander I. Tarasenko 2 1 Intellectual Maritime Technologies,
More informationVIBRATION PROBLEMS IN ENGINEERING
VIBRATION PROBLEMS IN ENGINEERING FIFTH EDITION W. WEAVER, JR. Professor Emeritus of Structural Engineering The Late S. P. TIMOSHENKO Professor Emeritus of Engineering Mechanics The Late D. H. YOUNG Professor
More informationDynamic Analysis of Pelton Turbine and Assembly
Dynamic Analysis of Pelton Turbine and Assembly Aman Rajak, Prateek Shrestha, Manoj Rijal, Bishal Pudasaini, Mahesh Chandra Luintel Department of Mechanical Engineering, Central Campus, Pulchowk, Institute
More informationCHAPTER 4 DESIGN AND ANALYSIS OF CANTILEVER BEAM ELECTROSTATIC ACTUATORS
61 CHAPTER 4 DESIGN AND ANALYSIS OF CANTILEVER BEAM ELECTROSTATIC ACTUATORS 4.1 INTRODUCTION The analysis of cantilever beams of small dimensions taking into the effect of fringing fields is studied and
More informationPLAT DAN CANGKANG (TKS 4219)
PLAT DAN CANGKANG (TKS 4219) SESI I: PLATES Dr.Eng. Achfas Zacoeb Dept. of Civil Engineering Brawijaya University INTRODUCTION Plates are straight, plane, two-dimensional structural components of which
More informationRESPONSE SPECTRUM METHOD FOR ESTIMATION OF PEAK FLOOR ACCELERATION DEMAND
RESPONSE SPECTRUM METHOD FOR ESTIMATION OF PEAK FLOOR ACCELERATION DEMAND Shahram Taghavi 1 and Eduardo Miranda 2 1 Senior catastrophe risk modeler, Risk Management Solutions, CA, USA 2 Associate Professor,
More informationCIVL 8/7117 Chapter 12 - Structural Dynamics 1/75. To discuss the dynamics of a single-degree-of freedom springmass
CIV 8/77 Chapter - /75 Introduction To discuss the dynamics of a single-degree-of freedom springmass system. To derive the finite element equations for the time-dependent stress analysis of the one-dimensional
More informationDevelopment of Laser Thickness Gauge in Steel Plate Shearing Line
JFE TECHNICAL REPORT No. 21 (Mar. 2016) Development of Laser Thickness Gauge in Steel Plate Shearing Line TEZUKA Koichi *1 Abstract: JFE Steel has developed a laser thickness gauge for the purpose of guaranteeing
More information1618. Dynamic characteristics analysis and optimization for lateral plates of the vibration screen
1618. Dynamic characteristics analysis and optimization for lateral plates of the vibration screen Ning Zhou Key Laboratory of Digital Medical Engineering of Hebei Province, College of Electronic and Information
More informationNonlinear Rolling Element Bearings in MADYN 2000 Version 4.3
- 1 - Nonlinear Rolling Element Bearings in MADYN 2000 Version 4.3 In version 4.3 nonlinear rolling element bearings can be considered for transient analyses. The nonlinear forces are calculated with a
More informationSTRUCTURAL DYNAMICS BASICS:
BASICS: STRUCTURAL DYNAMICS Real-life structures are subjected to loads which vary with time Except self weight of the structure, all other loads vary with time In many cases, this variation of the load
More informationA CONTINUOUS MODEL FOR THE VERTICAL VIBRATION OF THE HUMAN BODY IN A STANDING POSITION
ABSTRACT A CONTINUOUS MODEL FOR THE VERTICAL VIBRATION OF THE HUMAN BODY IN A STANDING POSITION Tianjian Ji Building Research Establishment, Watford, UK This paper is concerned with modelling the vertical
More informationEVALUATING DYNAMIC STRESSES OF A PIPELINE
EVALUATING DYNAMIC STRESSES OF A PIPELINE by K.T. TRUONG Member ASME Mechanical & Piping Division THE ULTRAGEN GROUP LTD 2255 Rue De La Province Longueuil (Quebec) J4G 1G3 This document is provided to
More informationMembers Subjected to Torsional Loads
Members Subjected to Torsional Loads Torsion of circular shafts Definition of Torsion: Consider a shaft rigidly clamped at one end and twisted at the other end by a torque T = F.d applied in a plane perpendicular
More informationDynamics of structures
Dynamics of structures 2.Vibrations: single degree of freedom system Arnaud Deraemaeker (aderaema@ulb.ac.be) 1 Outline of the chapter *One degree of freedom systems in real life Hypothesis Examples *Response
More informationA Study on the Tube of Integral Propeller Shaft for the Rear-wheel Drive Automobile Using Carbon Composite Fiber
A Study on the Tube of Integral Propeller Shaft for the Rear-wheel Drive Automobile Using Carbon Composite Fiber Kibong Han Mechatronics Department, Jungwon University, 85 Munmu-ro, Goesan-gun, South Korea.
More informationDYNAMIC RESPONSE OF THIN-WALLED GIRDERS SUBJECTED TO COMBINED LOAD
DYNAMIC RESPONSE OF THIN-WALLED GIRDERS SUBJECTED TO COMBINED LOAD P. WŁUKA, M. URBANIAK, T. KUBIAK Department of Strength of Materials, Lodz University of Technology, Stefanowskiego 1/15, 90-924 Łódź,
More informationVIBRATION RESPONSE OF AN ELECTRIC GENERATOR
Research Report BVAL35-001083 Customer: TEKES/SMART VIBRATION RESPONSE OF AN ELECTRIC GENERATOR Paul Klinge, Antti Hynninen Espoo, Finland 27 December, 2001 1 (12) Title A B Work report Public research
More informationInternational Journal of Advance Engineering and Research Development
Scientific Journal of Impact Factor (SJIF): 4.72 International Journal of Advance Engineering and Research Development Volume 4, Issue 11, November -2017 e-issn (O): 2348-4470 p-issn (P): 2348-6406 Study
More informationNON-LINEAR ANALYSIS OF SOIL-PILE-STRUCTURE INTERACTION UNDER SEISMIC LOADS
NON-LINEAR ANALYSIS OF SOIL-PILE-STRUCTURE INTERACTION UNDER SEISMIC LOADS Yingcai Han 1 and Shin-Tower Wang 2 1 Fluor Canada Ltd., Calgary AB, Canada Email: yingcai.han@fluor.com 2 Ensoft, Inc. Austin,
More informationWind Effects on the Forth Replacement Crossing
Wind Effects on the Forth Replacement Crossing M.N. Svendsen 1, M. Lollesgaard 2 and S.O. Hansen 2 1 RAMBØLL, DK. mnns@ramboll.dk 2 Svend Ole Hansen ApS, DK. Abstract The Forth Replacement Crossing is
More informationFundamentals of noise and Vibration analysis for engineers
Fundamentals of noise and Vibration analysis for engineers M.P.NORTON Department of Mechanical Engineering, University of Western Australia CAMBRIDGE UNIVERSITY PRESS Preface xii Acknowledgements xv Introductory
More information1820. Selection of torsional vibration damper based on the results of simulation
8. Selection of torsional vibration damper based on the results of simulation Tomasz Matyja, Bogusław Łazarz Silesian University of Technology, Faculty of Transport, Gliwice, Poland Corresponding author
More informationDynamics of Rotor Systems with Clearance and Weak Pedestals in Full Contact
Paper ID No: 23 Dynamics of Rotor Systems with Clearance and Weak Pedestals in Full Contact Dr. Magnus Karlberg 1, Dr. Martin Karlsson 2, Prof. Lennart Karlsson 3 and Ass. Prof. Mats Näsström 4 1 Department
More informationAN IMPROVED NUMERICAL MODEL FOR CALCULATING SHIP HULL FRAME TRANSVERSAL STRUCTURE
COMPUTATIONAL MECHANICS New Trends and Applications E. Oñate and S. R. Idelsohn (Eds.) CIMNE, Barcelona, Spain 1998 AN IMPROVED NUMERICAL MODEL FOR CALCULATING SHIP HULL FRAME TRANSVERSAL STRUCTURE Oscar
More informationParameter Design of High Speed Coupling for 6 MW Wind Turbine Considering Torsional Vibration
Parameter Design of High Speed Coupling for 6 MW Wind Turbine Considering Torsional Vibration JongHun Kang 1, Junwoo Bae 2, Seungkeun Jeong 3, SooKeun Park 4 and Hyoung Woo Lee 1 # 1 Department of Mechatronics
More informationVaruvan Vadivelan. Institute of Technology LAB MANUAL. : 2013 : B.E. MECHANICAL ENGINEERING : III Year / V Semester. Regulation Branch Year & Semester
Varuvan Vadivelan Institute of Technology Dharmapuri 636 703 LAB MANUAL Regulation Branch Year & Semester : 2013 : B.E. MECHANICAL ENGINEERING : III Year / V Semester ME 6511 - DYNAMICS LABORATORY GENERAL
More informationTRANSIENT RESPONSE OF SANDWICH AND LAMINATED COMPOSITES WITH DAMPING UNDER IMPULSE LOADING
TRANSIENT RESPONSE OF SANDWICH AND LAMINATED COMPOSITES WITH DAMPING UNDER IMPULSE LOADING Evgeny Barkanov, Andris Chate and Rolands Rikards Institute of Computer Analysis of Structures, Riga Technical
More informationExperimental Modal Analysis of a Flat Plate Subjected To Vibration
American Journal of Engineering Research (AJER) 2016 American Journal of Engineering Research (AJER) e-issn: 2320-0847 p-issn : 2320-0936 Volume-5, Issue-6, pp-30-37 www.ajer.org Research Paper Open Access
More informationExpedient Modeling of Ball Screw Feed Drives
S. Frey a A. Dadalau a A. Verl a Expedient Modeling of Ball Screw Feed Drives Stuttgart, February 2011 a Institute for Control Engineering of Machine Tools and Manufacturing Units (ISW), University of
More informationAnalysis of Tensioner Induced Coupling in Serpentine Belt Drive Systems
2008-01-1371 of Tensioner Induced Coupling in Serpentine Belt Drive Systems Copyright 2007 SAE International R. P. Neward and S. Boedo Department of Mechanical Engineering, Rochester Institute of Technology
More informationFinal Exam Solution Dynamics :45 12:15. Problem 1 Bateau
Final Exam Solution Dynamics 2 191157140 31-01-2013 8:45 12:15 Problem 1 Bateau Bateau is a trapeze act by Cirque du Soleil in which artists perform aerial maneuvers on a boat shaped structure. The boat
More informationModel tests and FE-modelling of dynamic soil-structure interaction
Shock and Vibration 19 (2012) 1061 1069 1061 DOI 10.3233/SAV-2012-0712 IOS Press Model tests and FE-modelling of dynamic soil-structure interaction N. Kodama a, * and K. Komiya b a Waseda Institute for
More informationFatigue Crack Analysis on the Bracket of Sanding Nozzle of CRH5 EMU Bogie
Journal of Applied Mathematics and Physics, 2015, 3, 577-583 Published Online May 2015 in SciRes. http://www.scirp.org/journal/jamp http://dx.doi.org/10.4236/jamp.2015.35071 Fatigue Crack Analysis on the
More informationModeling and Performance Analysis of a Flywheel Energy Storage System Prince Owusu-Ansah, 1, Hu Yefa, 1, Philip Agyeman, 1 Adam Misbawu 2
International Conference on Electromechanical Control Technology and Transportation (ICECTT 2015) Modeling and Performance Analysis of a Flywheel Energy Storage System Prince Owusu-Ansah, 1, Hu Yefa, 1,
More informationVibrations in Mechanical Systems
Maurice Roseau Vibrations in Mechanical Systems Analytical Methods and Applications With 112 Figures Springer-Verlag Berlin Heidelberg New York London Paris Tokyo Contents Chapter I. Forced Vibrations
More informationGrandstand Terraces. Experimental and Computational Modal Analysis. John N Karadelis
Grandstand Terraces. Experimental and Computational Modal Analysis. John N Karadelis INTRODUCTION Structural vibrations caused by human activities are not known to be particularly damaging or catastrophic.
More informationFundamentals of Structural Design Part of Steel Structures
Fundamentals of Structural Design Part of Steel Structures Civil Engineering for Bachelors 133FSTD Teacher: Zdeněk Sokol Office number: B619 1 Syllabus of lectures 1. Introduction, history of steel structures,
More information