Modal vibration control of submarine hulls
|
|
- Mercy Park
- 5 years ago
- Views:
Transcription
1 Modal vibration control of submarine hulls B. Alzahabi Department of Mechanical Engineering, Kettering University, USA Abstract Cylindrical shells are widely used in many structural designs, such as offshore structures, liquid storage tanks, submarine hulls, and airplane hulls. Most of these structures are required to operate in a dynamic environment. The acoustic signature of submarines is very critical in such a high performance structure. Submarines are not only required to sustain very high dynamic loadings at all times, but must also be able to maneuver and perform their functions under the sea without being detected by sonar systems. Reduction of sound radiation is most efficiently achieved at the design stage, and the acoustic signatures may be determined by considering operational scenarios and modal characteristics. The acoustic signature of submarines is generally of two categories: broadband which has a continuous spectrum; and a tonal noise which has discrete frequencies. Therefore, investigating the dynamic characteristics of a submarine hull is very critical in developing a strategy for modal vibration control for specific operating conditions. During the design optimization of a submarine hull, one is faced with some unique challenges. Unlike that of simpler structures such as beams and plates, the modal spectrum of a cylindrical shell exhibits very unique modal characteristics. The interrelationship between modes usually results in mode crossing, uniqueness of the modal spectrum, and the redundancy of modal constraints. Design optimization due to modal frequency constraints also results in nonunique solutions. Those designs must be examined for their modal frequency response to determine the best suitable design. In this paper, a strategy for modal vibration control is investigated. First, the modal characteristics of a submarine hull are examined. Second, the optimum design for modal frequency constraints is established. The frequency responses of the resulting optimum designs are compared. Third, a frequency response optimization is presented and compared with other models WIT Press, ISBN
2 56 High Performance Structures and Materials II Modal characteristics of submarine hull The modal spectrum of cylindrical shell exhibits very unique characteristics. Unlike that of simpler structures such as beams and plates, the lowest natural frequency in cylindrical shells does not necessarily correspond to the lowest wave index shown in Figure. In fact, the natural frequencies do not fall in ascending order of the wave index either, as indicated in Table. The eigen solutions also indicate multiple eigenvalues, i.e. repeated natural frequencies with similar mode shapes. These are referred to as double peak frequencies []. Shell displacements of each mode shape are defined in three orthogonal directions that are associated with radial (flexural), longitudinal (axial), and circumferential (torsional) components. n = n = 2 n=3 Circumferential Nodal Pattern m = m = 2 Longitudinal Nodal Pattern Figure : Normal mode patterns for simply supported cylindrical shells. The shell curvature results in a coupling between the transverse and in-plane vibration. Modes shapes associated with membrane shell deformations require a lot of strain energy while mode shapes associated with bending deformation require less strain energy. Since the total potential strain energy in a shell is the summation of both membrane and bending strain energy, the first mode shape corresponds to the lowest total energy that might not necessarily be at the lowest wave index n. The ratio between the membrane strain energy and the kinetic energy (or the total strain energy) is high for modes with simple modal patterns n 2004 WIT Press, ISBN
3 High Performance Structures and Materials II 57 and decrease toward zero as the number of nodal lines increases, while the ratio of the bending strain energy to the to kinetic energy (or the total strain energy) is small for simple nodal patterns and increase with the increase of wave index n [2] Total Strain energy Membrane Strain Energy Bending Strain Energy Energy Factor (lb.in) 'n' - Number of Circumferential Waves in the mode shape for m=. Figure 2: Energy distribution. Natural frequencies dominated by the membrane strain energy are approximately independent of the shell thickness change [3], and remain unchanged during shell optimization [4], while the natural frequencies controlled by bending stain energy vary with shell thickness. 2 Modal characteristics The finite element model of the cylindrical segment of a submarine hull, shown in Figure 3 is analyzed using the finite element software MSC.NASTRAN [5] to obtain its modal characteristics. The cylindrical shell segment has the following dimensions: length L = 594 in, radius R =98 in, thickness h = 2 in. The material properties of the shell are: Young s modulus E = 30 x 0 6 psi, Poisson s ratio ν = 0.3, Density ρ = x 0-4 lb.sec 2 /in 4. The modal characteristics of the cylindrical shell for shear diaphragm boundary conditions are summarized in Table WIT Press, ISBN
4 58 High Performance Structures and Materials II Figure 3: Table : Baseline finite element model of submarine hull segment. Modal Characteristics of baseline submarine hull segment. Mode Mode Frequency Strain Energy Density (lb/in 2 ) No. n m (Hz) Membrane Bending Design optimization I Modal frequency constraints A series of design optimizations were performed using SOL 200 module of MSC.NASTRAN [6]. For the optimization, the uniform submarine hull is segmented in the finite element model as a segmented cylinder made of nine equal length cylindrical segments along its length as shown in figure WIT Press, ISBN
5 High Performance Structures and Materials II 59 The thickness of each segment is taken as a design variable, totaling nine design variables for the optimization. Figure 4: Table 2: Nine design variables of baseline model. Non-uniqueness of design optimization. Thickness Baseline Design I Design II Design III Design IV T T T T T T T T T Mass (lb.sec 2 /in) Four different designs were obtained while optimizing each segment thickness to attain desired natural frequencies [7] for modes (n=4 to 7, m=). Predetermined natural frequencies for the four modes were used as design objectives in this optimization program utilizing normal mode analysis. The optimized designs were named as Design I, II, III & IV. Design I: The design objective is to increase the second mode (n = 4, m = ) natural frequency from baseline frequency f =2.89 Hz to design frequency f '=4.92 Hz. Design II: The design objective is to increase the third mode (n = 5, m = ) natural frequency from baseline frequency f 2 =4.3 Hz to design frequency f 2 '=8.69 Hz WIT Press, ISBN
6 520 High Performance Structures and Materials II Design III: The design objective is to increase the fifth mode (n = 6, m = ) natural frequency from baseline frequency f 3 =8.39 Hz to design frequency f 3 '= Hz. Design IV: The design objective is to increase the sixth mode (n = 5, m = ) natural frequency from baseline frequency f 4 =23.54 Hz to design frequency f 4 '=3.66 Hz. The optimization results show non-unique solution, i.e. there are many very different solutions having almost the same value of the goal function. The optimized thickness for the above four designs are as shown in Table 2. While the optimization process results in four non-unique solutions, they exhibit unique modal spectrum as listed in Table 3. Table 3: Uniqueness of modal spectrum. Mode No. n M Baseline n m Design I Design II Design III Design IV Modal frequency responses analysis The non-uniqueness of the optimization solution raises the question of choice of an appropriate design. To find the best solution among the various designs an additional analysis will be performed, i.e. the frequency response of the different designs. The steady state response of the shell due to a sinusoidal input force at discrete frequencies is studied using the modal frequency response analysis [5] in MSC.NASTRAN. Unit sinusoidal force acting in the X-direction is applied at the center of the cylinder while rigid bar is used to connect the center to a point on the cylinder as shown in figure 4. A sine sweep over the frequency range of 2 Hz to 32 Hz is performed and the structure s response (X-direction displacement) at the point of response is 2004 WIT Press, ISBN
7 High Performance Structures and Materials II 52 examined. Since, the structure is considered linear in the frequency response analysis; the response to the sinusoidal excitation will also be sinusoidal response, vibrating with the same frequency as the input but at a different phase. Figure 5, shows the cylinder s displacement in the X direction (magnitude in logarithmic scale) at the response point for the all four designs. Table 4, shows the values of the RMS (Root Mean Squares) summation of X-direction displacement for the various frequencies at the response point. Figure 5: Cylinder excited by a point force..e-03 Design I Design II Design III Design IV Baseline.E-04.E-05 X displ (log scale).e-06.e-07.e-08.e-09.e Frequency (Hz) Figure 6: Modal frequency response for all designs WIT Press, ISBN
8 522 High Performance Structures and Materials II Table 4: Design summary optimization I. Baseline Design I Design II Design III Design IV Σ RMS 3.7E-07.E E-08.2E E-08 5 Optimization II - modal frequency response approach To further investigate an appropriate optimized design for the submarine hull segment, a frequency response optimization is performed. The RMS was taken as the objective function and considering a desired frequency as a design constraint. This was accomplished using the multidisciplinary design optimization module in MSC.NASTRAN. For each of the modal frequency response optimization, unit sinusoidal force in the X-direction is applied on a circular ring of nodes lying at the start of the fifth segment. The forces applied are in phase, swept through discrete frequencies from 2 Hz to 32 Hz. Subjecting the cylindrical shell to excitation forces all along the circular ring ensures all mode shapes are excited irrespective of the excitation location. Also to take into account the responses due to all modes, the Root Mean Squares (RMS) of the X- direction displacement at each of the excitation locations is summed up for every discrete frequency of excitation used. During optimization, the design objective is designed to reduce this RMS summation value. The design constraint in each design case is the predetermined frequency values for the first four mode shapes. The resulting four design variants are named as Design V, VI, VII and VIII. Table 5: Non-uniqueness of design optimization II. Thickness Baseline Design V Design VI Design VII Design VIII T T T T T T T T T Mass (lb.sec 2 /in) Design V: The objective is to minimize the root mean square sum of X-dir displacements and the design constraint is that the natural frequency of the second mode (n = 4, m = ) is f '=4.92 Hz WIT Press, ISBN
9 High Performance Structures and Materials II 523 Design VI: The objective is to minimize the root mean square sum of X-dir displacements and the design constraint is that the natural frequency of the third mode (n = 5, m = ) is f 2 '=8.69 Hz. Design VII: The objective is to minimize the root mean square sum of X-dir displacements and the design constraint is that the natural frequency of the fifth mode (n = 6, m = ) is f 3 '=24.94 Hz. Design VIII: The objective is to minimize the root mean square sum of X-dir displacements and the design constraint is that the natural frequency of the sixth mode (n = 7, m = ) is f 4 '=3.66 Hz. Optimized segment thickness for the above designs is shown in Table 5. The corresponding modal spectrums of these four designs are shown in Table 6. The corresponding modal spectra of these four designs are shown in Table 6. The modal frequency functions at the response point in the X direction displacement are shown in logarithmic scale in Figure 7. The corresponding values of the RMS (Root Mean Squares) summation of X- direction displacement for the all frequencies at the response point are listed in Table 7. Table 6: Uniqueness of modal spectrum. Mode No. n m Baseline n m Design V Design VI Design VII Design VIII Table 7: Design summary optimization II. Baseline Design V Design VI Design VII Design VIII Σ RMS 3.7E E-08 2.E-08 2.E E WIT Press, ISBN
10 524 High Performance Structures and Materials II 6 Concluding remarks Based on the modal frequency response (Optimization I), Design II is the best design obtained in using normal mode approach optimization, while Design VI is the best design obtained using the modal frequency response approach (Optimization II). However, in terms of mass increase relative to the baseline design, Design I and Design VII showed relatively lesser increase in their masses. In terms of lower increase in mass, and lower RMS summation of modal response Design V proved to be the best..e-03 Design V Design VI Design VII Design VIII Baseline.E-04.E-05 X displ (log scale).e-06.e-07.e-08.e-09.e Frequency (Hz) Figure 7: Modal frequency response for baseline design. References [] Soedel, W., "Shell Vibration Without Mathematics Part I", S/V, Vol. 9, No., November 975, pp [2] Soedel, W., "Shell Vibration Without Mathematics Part II", S/V, Vol. 0, No. 4, April 976, pp [3] Alzahabi, B., Natarajan, L. K. Analytical Solution of Circular Cylindrical Shell Vibrations, Proceeding of the ISMA 2002 International Conference on Noise & Vibration Engineering, 6-8 September 2002, Leuven, Belgium WIT Press, ISBN
11 High Performance Structures and Materials II 525 [4] Alzahabi, B. Optimum Design of Submarine Hulls, Proceeding of the International Conference on High Performance Structures and Composites, Seville, Spain, - 3 March 2002, pp [5] MSC.visualNastran Quick Reference Guide, 200, MSC.Software, Santa Ana, CA, 200. [6] MSC/NASTRAN Optimization and Design Sensitivity, 200, MSC.Software, Santa Ana, CA, 200. [7] Alzahabi, B., Bernitsas, M.M., "Redesign of Cylindrical Shells by Large Admissible Perturbations", Journal of Ship Research, Vol. 45, No. 3, September 200, pp WIT Press, ISBN
Optimum design of submarine hulls
00 WIT Press, Ashurst Lodge, Southampton, SO0 AA, UK. All rights reserved. ISBN 890 Optimum design of submarine hulls Basem Alzahabi Department of Mechanical Engineering Kettering University, Flint, MI,
More informationVIBRATIONAL MODES OF THICK CYLINDERS OF FINITE LENGTH
Journal of Sound and Vibration (1996) 191(5), 955 971 VIBRATIONAL MODES OF THICK CYLINDERS OF FINITE LENGTH Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
More informationMode-based Frequency Response Function and Steady State Dynamics in LS-DYNA
11 th International LS-DYNA Users Conference Simulation (3) Mode-based Frequency Response Function and Steady State Dynamics in LS-DYNA Yun Huang 1, Bor-Tsuen Wang 2 1 Livermore Software Technology Corporation
More informationBorehole vibration response to hydraulic fracture pressure
Borehole vibration response to hydraulic fracture pressure Andy St-Onge* 1a, David W. Eaton 1b, and Adam Pidlisecky 1c 1 Department of Geoscience, University of Calgary, 2500 University Drive NW Calgary,
More informationA detailed experimental modal analysis of a clamped circular plate
A detailed experimental modal analysis of a clamped circular plate David MATTHEWS 1 ; Hongmei SUN 2 ; Kyle SALTMARSH 2 ; Dan WILKES 3 ; Andrew MUNYARD 1 and Jie PAN 2 1 Defence Science and Technology Organisation,
More informationNUMERICAL COMPARISON OF ACTIVE ACOUSTIC AND STRUCTURAL NOISE CONTROL IN A STIFFENED DOUBLE WALL CYLINDER
BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB NUMERICAL COMPARISON OF ACTIVE ACOUSTIC AND STRUCTURAL NOISE CONTROL IN A STIFFENED DOUBLE WALL CYLINDER Ferdinand W. Grosveld * Lockheed Martin Engineering
More information15-8 1/31/2014 PRELAB PROBLEMS 1. Why is the boundary condition of the cavity such that the component of the air displacement χ perpendicular to a wall must vanish at the wall? 2. Show that equation (5)
More informationModal Analysis of Microcantilever using Vibration Speaker
Modal Analysis of Microcantilever using Vibration Speaker M SATTHIYARAJU* 1, T RAMESH 2 1 Research Scholar, 2 Assistant Professor Department of Mechanical Engineering, National Institute of Technology,
More informationImplementation and Validation of Frequency Response Function in LS-DYNA
Implementation and Validation of Frequency Response Function in LS-DYNA Yun Huang 1, Bor-Tsuen Wang 2 1 Livermore Software Technology Corporation 7374 Las Positas Rd., Livermore, CA, United States 94551
More informationActive Vibration Control of Finite Thin-Walled Cylindrical Shells
THE UNIVERSITY OF NEW SOUTH WALES SCHOOL OF MECHANICAL AND MANUFACTURING ENGINEERING Active Vibration Control of Finite Thin-Walled Cylindrical Shells Timothy McGann 3158829 Bachelor of Engineering (Mechanical)
More informationModal Parameter Estimation Using Acoustic Modal Analysis
Proceedings of the IMAC-XXVIII February 1 4, 2010, Jacksonville, Florida USA 2010 Society for Experimental Mechanics Inc. Modal Parameter Estimation Using Acoustic Modal Analysis W. Elwali, H. Satakopan,
More informationMode Dispersion Curves
Mode Dispersion Curves Fluid-Filled Pipe using FEM George Grigoropoulos Civil Engineer, MSc. g.grigoropoulos@gmail.com Department of Civil and Environmental Engineering Hong Kong University of Science
More informationModel Correlation of Dynamic Non-linear Bearing Behavior in a Generator
Model Correlation of Dynamic Non-linear Bearing Behavior in a Generator Dean Ford, Greg Holbrook, Steve Shields and Kevin Whitacre Delphi Automotive Systems, Energy & Chassis Systems Abstract Efforts to
More informationA violin shell model: Vibrational modes and acoustics
A violin shell model: Vibrational modes and acoustics Colin E. Gough a) School of Physics and Astronomy, University of Birmingham, Birmingham B15 2TT, United Kingdom (Received 17 May 2014; revised 6 February
More informationCONTENTS. Cambridge University Press Vibration of Mechanical Systems Alok Sinha Table of Contents More information
CONTENTS Preface page xiii 1 Equivalent Single-Degree-of-Freedom System and Free Vibration... 1 1.1 Degrees of Freedom 3 1.2 Elements of a Vibratory System 5 1.2.1 Mass and/or Mass-Moment of Inertia 5
More informationVeröffentlichungen am IKFF PIEZOELECTRIC TRAVELLING WAVE MOTORS GENERATING DIRECT LINEAR MOTION
Veröffentlichungen am IKFF PIEZOELECTRIC TRAVELLING WAVE MOTORS GENERATING DIRECT LINEAR MOTION M. Hermann, W. Schinköthe (IKFF) Beitrag zur Actuator 96 Bremen 26. - 28.06.96 Conference Proceedings, S.
More informationA GENERIC SHELL MODEL FOR INSTRUMENTS OF THE VIOLIN FAMILY
A GENERIC SHELL MODEL FOR INSTRUMENTS OF THE VIOLIN FAMILY CE Gough School of Physics and Astronomy, University of Birmingham, B15 2TT, UK. 1 INTRODUCTION A number of simple models have been introduced
More informationOptimizing the Natural Frequencies of Beams via Notch Stamping
Research Journal of Applied Sciences, Engineering and Technology 4(14): 2030-2035, 2012 ISSN: 2040-7467 Maxwell Scientific Organization, 2012 Submitted: December 02, 2011 Accepted: December 26, 2011 Published:
More informationMODEL MODIFICATION OF WIRA CENTER MEMBER BAR
MODEL MODIFICATION OF WIRA CENTER MEMBER BAR F.R.M. Romlay & M.S.M. Sani Faculty of Mechanical Engineering Kolej Universiti Kejuruteraan & Teknologi Malaysia (KUKTEM), Karung Berkunci 12 25000 Kuantan
More informationExperimental investigation of crack in aluminum cantilever beam using vibration monitoring technique
International Journal of Computational Engineering Research Vol, 04 Issue, 4 Experimental investigation of crack in aluminum cantilever beam using vibration monitoring technique 1, Akhilesh Kumar, & 2,
More informationUse of Orthogonal Arrays for Efficient Evaluation of Geometric Designs for Reducing Vibration of a Non-Pneumatic Wheel During High-Speed Rolling
Clemson University TigerPrints All Theses Theses 8-2009 Use of Orthogonal Arrays for Efficient Evaluation of Geometric Designs for Reducing Vibration of a Non-Pneumatic Wheel During High-Speed Rolling
More informationMultiple crack detection of pipes using PZT-based guided waves
Multiple crack detection of pipes using PZT-based guided waves *Shi Yan 1), Ji Qi 2), Nai-Zhi Zhao 3), Yang Cheng 4) and Sheng-Wenjun Qi 5) 1), 2), 3), 4) School of Civil Engineering, Shenyang Jianzhu
More informationA Simulation Study of Attenuation Factors in a Gas Pipeline Guided Wave Testing
Proceedings of the 4th Iranian International NDT Conference Feb 26-27, 2017, Olympic Hotel, Tehran, Iran IRNDT 2017 A Simulation Study of Attenuation Factors in a Gas Pipeline Guided Wave Testing M. J.
More informationStudies on free vibration of FRP aircraft Instruments panel boards
89 Studies on free vibration of FRP aircraft Instruments panel boards E. Chandrasekaran Professor in Dept. of Civil Engineering, Crescent Engineering College 648 India. e-mail: sekharan@vsnl.net and K.
More informationLIQUID SLOSHING IN FLEXIBLE CONTAINERS, PART 1: TUNING CONTAINER FLEXIBILITY FOR SLOSHING CONTROL
Fifth International Conference on CFD in the Process Industries CSIRO, Melbourne, Australia 13-15 December 26 LIQUID SLOSHING IN FLEXIBLE CONTAINERS, PART 1: TUNING CONTAINER FLEXIBILITY FOR SLOSHING CONTROL
More informationFastener Modeling for Joining Parts Modeled by Shell and Solid Elements
2007-08 Fastener Modeling for Joining Parts Modeled by Shell and Solid Elements Aleander Rutman, Chris Boshers Spirit AeroSystems Larry Pearce, John Parady MSC.Software Corporation 2007 Americas Virtual
More informationEQUIVALENT THROAT TECHNOLOGY
EQUIVALENT THROAT TECHNOLOGY Modern audio frequency reproduction systems use transducers to convert electrical energy to acoustical energy. Systems used for the reinforcement of speech and music are referred
More informationMonitoring The Machine Elements In Lathe Using Vibration Signals
Monitoring The Machine Elements In Lathe Using Vibration Signals Jagadish. M. S. and H. V. Ravindra Dept. of Mech. Engg. P.E.S.C.E. Mandya 571 401. ABSTRACT: In any manufacturing industry, machine tools
More informationThe Physics of Musical Instruments
Neville H. Fletcher Thomas D. Rossing The Physics of Musical Instruments Second Edition With 485 Illustrations Springer Contents Preface Preface to the First Edition v vii I. Vibrating Systems 1. Free
More informationFLUTTER CONTROL OF WIND TUNNEL MODEL USING A SINGLE ELEMENT OF PIEZO-CERAMIC ACTUATOR
24 TH INTERNATIONAL CONGRESS OF THE AERONAUTICAL SCIENCES FLUTTER CONTROL OF WIND TUNNEL MODEL USING A SINGLE ELEMENT OF PIEZO-CERAMIC ACTUATOR Naoki Kawai Department of Mechanical Engineering, University
More informationSolution of Pipeline Vibration Problems By New Field-Measurement Technique
Purdue University Purdue e-pubs International Compressor Engineering Conference School of Mechanical Engineering 1974 Solution of Pipeline Vibration Problems By New Field-Measurement Technique Michael
More informationEnhancing the low frequency vibration reduction performance of plates with embedded Acoustic Black Holes
Enhancing the low frequency vibration reduction performance of plates with embedded Acoustic Black Holes Stephen C. CONLON 1 ; John B. FAHNLINE 1 ; Fabio SEMPERLOTTI ; Philip A. FEURTADO 1 1 Applied Research
More informationStructural. engineering. dynamics of earthquake. s. Rajasekaran. W OODHEAD PUBLISHING LIMITED Oxford Cambridge New Delhi
Structural dynamics of earthquake engineering Theory and application using MATHEMATICA and MATLAB s. Rajasekaran ocrc Press Boca Raton Boston New York Washington, DC W OODHEAD PUBLISHING LIMITED Oxford
More informationMODELLING AND EXPERIMENTS FOR THE DEVELOPMENT OF A GUIDED WAVE LIQUID LEVEL SENSOR
Proceedings of the National Seminar & Exhibition on Non-Destructive Evaluation NDE 2011, December 8-10, 2011 MODELLING AND EXPERIMENTS FOR THE DEVELOPMENT OF A GUIDED WAVE LIQUID LEVEL SENSOR Subhash N.N
More informationPipe Testing Using Guided Waves
70 Pipe Testing Using Guided Waves S. Adalarasu Proceedings of the National Seminar & Exhibition on Non-Destructive Evaluation NDTF, QCI, MEE, Vikram Sarabhai Space Centre NDE 2009, December 10-12, 2009
More informationAn Alternative to Pyrotechnic Testing For Shock Identification
An Alternative to Pyrotechnic Testing For Shock Identification J. J. Titulaer B. R. Allen J. R. Maly CSA Engineering, Inc. 2565 Leghorn Street Mountain View, CA 94043 ABSTRACT The ability to produce a
More information9th WSEAS Int. Conf. on ACOUSTICS & MUSIC: THEORY & APPLICATIONS (AMTA '08), Bucharest, Romania, June 24-26, 2008
Correlations between the Plates Vibrations from the Guitar s Structure and the Physical, Mechanical and Elastically Characteristics of the Composite Materials IOAN CURTU MARIANA DOMNICA STANCIU Department
More informationDepartment of Physics United States Naval Academy. Lecture 39: Sound Waves
Department of Physics United States Naval Academy Lecture 39: Sound Waves Sound Waves: Sound waves are longitudinal mechanical waves that can travel through solids, liquids, or gases. The speed v of a
More informationMULTISTAGE COUPLING OF MISTUNED AIRCRAFT ENGINE BLADED DISKS IN A FREE VIBRATION ANALYSIS
11 th International Conference on Vibration Problems Z. Dimitrovová et al. (eds.) Lisbon, Portugal, 9-12 September 2013 MULTISTAGE COUPLING OF MISTUNED AIRCRAFT ENGINE BLADED DISKS IN A FREE VIBRATION
More informationTyre Cavity Coupling Resonance and Countermeasures Zamri Mohamed 1,a, Laith Egab 2,b and Xu Wang 2,c
Tyre Cavity Coupling Resonance and Countermeasures Zamri Mohamed 1,a, Laith Egab,b and Xu Wang,c 1 Fakulti Kej. Mekanikal, Univ. Malaysia Pahang, Malaysia 1, School of Aerospace, Mechanical and Manufacturing
More informationA study of Vibration Analysis for Gearbox Casing Using Finite Element Analysis
A study of Vibration Analysis for Gearbox Casing Using Finite Element Analysis M. Sofian D. Hazry K. Saifullah M. Tasyrif K.Salleh I.Ishak Autonomous System and Machine Vision Laboratory, School of Mechatronic,
More informationStrength of Material-I (CE-207)
Strength of Material-I (CE-207) Course Contents: Types of stresses and strains Statically indeterminate problems Mechanical Properties of materials Thermal stresses Advanced cases of shearing forces and
More informationChapter 18. Superposition and Standing Waves
Chapter 18 Superposition and Standing Waves Particles & Waves Spread Out in Space: NONLOCAL Superposition: Waves add in space and show interference. Do not have mass or Momentum Waves transmit energy.
More informationLORENTZ FORCE DETUNING ANALYSIS OF THE SPALLATION NEUTRON SOURCE (SNS) ACCELERATING CAVITIES *
LORENTZ FORCE DETUNING ANALYSIS OF THE SPALLATION NEUTRON SOURCE (SNS) ACCELERATING CAVITIES * R. Mitchell, K. Matsumoto, Los Alamos National Lab, Los Alamos, NM 87545, USA G. Ciovati, K. Davis, K. Macha,
More informationSound, acoustics Slides based on: Rossing, The science of sound, 1990.
Sound, acoustics Slides based on: Rossing, The science of sound, 1990. Acoustics 1 1 Introduction Acoustics 2! The word acoustics refers to the science of sound and is a subcategory of physics! Room acoustics
More informationULTRASONIC GUIDED WAVES FOR AGING WIRE INSULATION ASSESSMENT
ULTRASONIC GUIDED WAVES FOR AGING WIRE INSULATION ASSESSMENT Robert F. Anastasi 1 and Eric I. Madaras 2 1 U.S. Army Research Laboratory, Vehicle Technology Directorate, AMSRL-VT-S, Nondestructive Evaluation
More informationDynamic Modeling of Air Cushion Vehicles
Proceedings of IMECE 27 27 ASME International Mechanical Engineering Congress Seattle, Washington, November -5, 27 IMECE 27-4 Dynamic Modeling of Air Cushion Vehicles M Pollack / Applied Physical Sciences
More informationAn FEA-Based Acoustic Fatigue Analysis Methodology
An FEA-Based Acoustic Fatigue Analysis Methodology Timothy C. Allison, Ph.D. Lawrence J. Goland, P.E. Southwest Research Institute San Antonio, TX ANSYS Regional Conference: Engineering the System August
More informationFailure of Engineering Materials & Structures. Code 34. Bolted Joint s Relaxation Behavior: A FEA Study. Muhammad Abid and Saad Hussain
Failure of Engineering Materials & Structures Code 3 UET TAXILA MECHNICAL ENGINEERING DEPARTMENT Bolted Joint s Relaxation Behavior: A FEA Study Muhammad Abid and Saad Hussain Faculty of Mechanical Engineering,
More informationStudy on a Single-Axis Fabry-Perot Fiber-Optic Accelerometer and its Signal Demodulation Method
Advances in Computer Science Research (ACSR) volume 5 016 International Conference on Computer Engineering and Information Systems (CEIS-16) Study on a Single-Axis abry-perot iber-optic Accelerometer and
More information0.20. Record Page 1 of 19
Page 1 of 19 Page 2 of 19 Page 3 of 19 Page 4 of 19 Page 5 of 19 ASME BPVC.III.1.ND-2015 Page 6 of 19 ð15þ Figure ND-3325-1 Some Acceptable Types of Unstayed Flat Heads and Covers GENERAL NOTE: The illustrations
More informationPrinted in U.S.A., Copyright Penton Media, Inc. All rights reserved. Machine Design (ISSN ) is published semimonthly by Penton Media,
Printed in U.S.A., Copyright 2002. Penton Media, Inc. All rights reserved. Machine Design (ISSN 0024-9114) is published semimonthly by Penton Media, Inc., 1300 E. 9th Steet, Cleveland, OH 44114 Copies
More informationSTP-PT-032 BUCKLING OF CYLINDRICAL, THIN WALL, TRAILER TRUCK TANKS AND ASME SECTION XII
STP-PT-032 BUCKLING OF CYLINDRICAL, THIN WALL, TRAILER TRUCK TANKS AND ASME SECTION XII Date of Issuance: September 1, 2009 This report was prepared as an account of work sponsored by ASME Pressure Technologies
More information(A) 2f (B) 2 f (C) f ( D) 2 (E) 2
1. A small vibrating object S moves across the surface of a ripple tank producing the wave fronts shown above. The wave fronts move with speed v. The object is traveling in what direction and with what
More informationStatus of Coil Structural Design and Magnetic-Structural Analysis
Status of Coil Structural Design and Magnetic-Structural Analysis Presented by X.R. Wang Contributors: ORNL: D. Williamson UCSD: S. Malang, A.R. Raffray UW: C. Martin ARIES Meeting UC San Diego, San Diego
More informationMonopile as Part of Aeroelastic Wind Turbine Simulation Code
Monopile as Part of Aeroelastic Wind Turbine Simulation Code Rune Rubak and Jørgen Thirstrup Petersen Siemens Wind Power A/S Borupvej 16 DK-7330 Brande Denmark Abstract The influence on wind turbine design
More informationAbout Doppler-Fizeau effect on radiated noise from a rotating source in cavitation tunnel
PROCEEDINGS of the 22 nd International Congress on Acoustics Signal Processing in Acoustics (others): Paper ICA2016-111 About Doppler-Fizeau effect on radiated noise from a rotating source in cavitation
More informationResonance frequencies of a spherical aluminum shell subject to static internal pressure
Resonance frequencies of a spherical aluminum shell subject to static internal pressure Andrew A. Piacsek and Sami Abdul-Wahid Department of Physics, Central Washington University, Ellensburg, Washington
More informationExperimental Investigation of Crack Detection in Cantilever Beam Using Natural Frequency as Basic Criterion
INSTITUTE OF TECHNOLOGY, NIRMA UNIVERSITY, AHMEDABAD 382 481, 08-10 DECEMBER, 2011 1 Experimental Investigation of Crack Detection in Cantilever Beam Using Natural Frequency as Basic Criterion A. A.V.Deokar,
More informationEWGAE 2010 Vienna, 8th to 10th September
EWGAE 2010 Vienna, 8th to 10th September Frequencies and Amplitudes of AE Signals in a Plate as a Function of Source Rise Time M. A. HAMSTAD University of Denver, Department of Mechanical and Materials
More informationCorrelation of the Vibroacoustic Response of Structural Panels with Isight for use in Statistical Energy Analysis in Aerospace Applications
Correlation of the Vibroacoustic Response of Structural Panels with Isight for use in Statistical Energy Analysis in Aerospace Applications ATA Engineering, Inc. 11995 El Camino Real, Suite 200 San Diego,
More informationInfluence of the Vibrational Properties of the Resonance Board on the Acoustical Quality of a Piano
Influence of the Vibrational Properties of the Resonance Board on the Acoustical Quality of a Piano Zhenbo Liu,* Yixing Liu, and Jun Shen The vibrational properties of eight resonance boards made from
More informationAN ADAPTIVE VIBRATION ABSORBER
AN ADAPTIVE VIBRATION ABSORBER Simon Hill, Scott Snyder and Ben Cazzolato Department of Mechanical Engineering, The University of Adelaide Australia, S.A. 5005. Email: simon.hill@adelaide.edu.au 1 INTRODUCTION
More informationENHANCEMENT OF THE TRANSMISSION LOSS OF DOUBLE PANELS BY MEANS OF ACTIVELY CONTROLLING THE CAVITY SOUND FIELD
ENHANCEMENT OF THE TRANSMISSION LOSS OF DOUBLE PANELS BY MEANS OF ACTIVELY CONTROLLING THE CAVITY SOUND FIELD André Jakob, Michael Möser Technische Universität Berlin, Institut für Technische Akustik,
More informationInvestigation of sound. of sound radiation by automotive tyres vibrating at low resonant frequencies.
Loughborough University Institutional Repository Investigation of sound radiation by automotive tyres vibrating at low resonant frequencies This item was submitted to Loughborough University's Institutional
More informationPile driving of large diameter monopiles: Current practice and challenges
Pile driving of large diameter monopiles: Current practice and challenges Peter Meijers Delft University of Technology, The Netherlands Factulty of Civil Engineering and Geosciences Section of Offshore
More informationDesign, Fabrication, and Validation of an Ultra-Lightweight Membrane Mirror
Design, Fabrication, and Validation of an Ultra-Lightweight Membrane Mirror Surya Chodimella, James D. Moore, Brian G. Patrick SRS Technologies, Huntsville AL, USA 35806 Brett deblonk, Dan K. Marker Air
More informationSHOCK AND VIBRATION RESPONSE SPECTRA COURSE Unit 4. Random Vibration Characteristics. By Tom Irvine
SHOCK AND VIBRATION RESPONSE SPECTRA COURSE Unit 4. Random Vibration Characteristics By Tom Irvine Introduction Random Forcing Function and Response Consider a turbulent airflow passing over an aircraft
More informationSound Spectra. Periodic Complex Waves. Ohm s law of hearing 4/6/09. What is the spectrum of the complex wave (thick dotted line)?
Sound Spectra The frequencies of all the sinusoidal component that make it up The amplitude of each sinusoidal component present Periodic Complex Waves The repetition frequency determines the pitch The
More informationResonance Tube. 1 Purpose. 2 Theory. 2.1 Air As A Spring. 2.2 Traveling Sound Waves in Air
Resonance Tube Equipment Capstone, complete resonance tube (tube, piston assembly, speaker stand, piston stand, mike with adapters, channel), voltage sensor, 1.5 m leads (2), (room) thermometer, flat rubber
More informationIJSRD - International Journal for Scientific Research & Development Vol. 4, Issue 05, 2016 ISSN (online):
IJSRD - International Journal for Scientific Research & Development Vol. 4, Issue 05, 2016 ISSN (online): 2321-0613 Static Analysis of VMC Spindle for Maximum Cutting Force Mahesh M. Ghadage 1 Prof. Anurag
More informationFATIGUE CRACK CHARACTERIZATION IN CONDUCTING SHEETS BY NON
FATIGUE CRACK CHARACTERIZATION IN CONDUCTING SHEETS BY NON CONTACT STIMULATION OF RESONANT MODES Buzz Wincheski, J.P. Fulton, and R. Todhunter Analytical Services and Materials 107 Research Drive Hampton,
More informationSound Spectra. Periodic Complex Waves 4/6/09
Sound Spectra The frequencies of all the sinusoidal component that make it up The amplitude of each sinusoidal component present Periodic Complex Waves The repetition frequency determines the pitch The
More informationAcoustic Resonance Analysis Using FEM and Laser Scanning For Defect Characterization in In-Process NDT
ECNDT 2006 - We.4.8.1 Acoustic Resonance Analysis Using FEM and Laser Scanning For Defect Characterization in In-Process NDT Ingolf HERTLIN, RTE Akustik + Prüftechnik, Pfinztal, Germany Abstract. This
More informationASSESSMENT OF BASIC STEEL I-SECTION BEAM BRACING REQUIREMENTS BY TEST SIMULATION
ASSESSMENT OF BASIC STEEL I-SECTION BEAM BRACING REQUIREMENTS BY TEST SIMULATION A Thesis By Evan P. Prado In Partial Fulfillment Of the Requirements for the Degree Master of Science in Civil Engineering
More informationComposite square and monomial power sweeps for SNR customization in acoustic measurements
Proceedings of 20 th International Congress on Acoustics, ICA 2010 23-27 August 2010, Sydney, Australia Composite square and monomial power sweeps for SNR customization in acoustic measurements Csaba Huszty
More informationModule 10 : Improvement of rock mass responses. Content
IMPROVEMENT OF ROCK MASS RESPONSES Content 10.1 INTRODUCTION 10.2 ROCK REINFORCEMENT Rock bolts, dowels and anchors 10.3 ROCK BOLTING MECHANICS Suspension theory Beam building theory Keying theory 10.4
More informationNoise from Pulsating Supercavities Prepared by:
Noise from Pulsating Supercavities Prepared by: Timothy A. Brungart Samuel E. Hansford Jules W. Lindau Michael J. Moeny Grant M. Skidmore Applied Research Laboratory The Pennsylvania State University Flow
More informationFinite Element Analysis and Test of an Ultrasonic Compound Horn
World Journal of Engineering and Technology, 2017, 5, 351-357 http://www.scirp.org/journal/wjet ISSN Online: 2331-4249 ISSN Print: 2331-4222 Finite Element Analysis and Test of an Ultrasonic Compound Horn
More informationFinite Element Modeling and Simulation of Ultrasonic Guided Wave Propagation using Frequency Response Analysis
More Info at Open Access Database www.ndt.net/?id=593 Finite Element Modeling and Simulation of Ultrasonic Guided Wave Propagation using Frequency Response Analysis Bikash Ghose, a, Krishnan Balasubramaniam
More informationNumerical Modeling of Grouted Soil Nails
Numerical Modeling of Grouted Soil Nails Dr. Haider S. Al -Jubair Department of Civil Engineering University of Basrah-College of Engineering Basrah, Iraq Afaf A. Maki Department of Civil Engineering University
More informationUniversity Physics (Prof. David Flory) Chapt_17 Monday, November 26, 2007 Page 1
University Physics (Prof. David Flory) Chapt_17 Monday, November 26, 2007 Page 1 Name: Date: 1. A 40-cm long string, with one end clamped and the other free to move transversely, is vibrating in its fundamental
More informationGENERAL GUIDELINES FOR APPLICATION OF THE EXTENDED SUBTRACTION METHOD IN SASSI SOIL-STRUCTURE INTERACTION ANALYSIS
Transactions, SMiRT-22 GENERAL GUIDELINES FOR APPLICATION OF THE EXTENDED SUBTRACTION METHOD IN SASSI SOIL-STRUCTURE INTERACTION ANALYSIS C. C. Chin 1, Nan Deng 2, and Farhang Ostadan 3 1 Senior Engineer,
More informationROBUST PARAMETER DESIGN AND FINITE ELEMENT ANALYSIS FOR A NON- PNEUMATIC TIRE WITH LOW VIBRATION
Clemson University TigerPrints All Theses Theses 12-2009 ROBUST PARAMETER DESIGN AND FINITE ELEMENT ANALYSIS FOR A NON- PNEUMATIC TIRE WITH LOW VIBRATION Amarnath Proddaturi Clemson University, aprodda@clemson.edu
More informationFINITE ELEMENT ANALYSIS OF ACTIVE VIBRATION ISOLATION
FIFTH INTERNATIONAL w CONGRESS ON SOUND AND VIBRATION DECEMBER 15-18, 1997 ADELAIDE, SOUTH AUSTRALIA Invited Paper FINITE ELEMENT ANALYSIS OF ACTIVE VIBRATION ISOLATION Carl Q. Howard and Colin H. Hansen
More informationVLSI Layout Based Design Optimization of a Piezoresistive MEMS Pressure Sensors Using COMSOL
VLSI Layout Based Design Optimization of a Piezoresistive MEMS Pressure Sensors Using COMSOL N Kattabooman 1,, Sarath S 1, Rama Komaragiri *1, Department of ECE, NIT Calicut, Calicut, Kerala, India 1 Indian
More informationResonance Tube Lab 9
HB 03-30-01 Resonance Tube Lab 9 1 Resonance Tube Lab 9 Equipment SWS, complete resonance tube (tube, piston assembly, speaker stand, piston stand, mike with adaptors, channel), voltage sensor, 1.5 m leads
More informationCopyright 2009 Pearson Education, Inc.
Chapter 16 Sound 16-1 Characteristics of Sound Sound can travel through h any kind of matter, but not through a vacuum. The speed of sound is different in different materials; in general, it is slowest
More informationModeling and Control of Mold Oscillation
ANNUAL REPORT UIUC, August 8, Modeling and Control of Mold Oscillation Vivek Natarajan (Ph.D. Student), Joseph Bentsman Department of Mechanical Science and Engineering University of Illinois at UrbanaChampaign
More informationANALYSIS OF LATERAL STIFFNESS FOR INFILLED FRAME WITH OPENING
ANALYSIS OF LATERAL STIFFNESS FOR INFILLED FRAME WITH OPENING A.S. KASNALE 1 & SANJAY JAMKAR 2 Professor in Civil Engineering Department, M.S. Bidve Engineering College, Latur, India Professor in Civil
More informationResonance Tube. 1 Purpose. 2 Theory. 2.1 Air As A Spring. 2.2 Traveling Sound Waves in Air
Resonance Tube Equipment Capstone, complete resonance tube (tube, piston assembly, speaker stand, piston stand, mike with adaptors, channel), voltage sensor, 1.5 m leads (2), (room) thermometer, flat rubber
More informationMulti-channel Active Control of Axial Cooling Fan Noise
The 2002 International Congress and Exposition on Noise Control Engineering Dearborn, MI, USA. August 19-21, 2002 Multi-channel Active Control of Axial Cooling Fan Noise Kent L. Gee and Scott D. Sommerfeldt
More informationULTRASONIC GUIDED WAVE FOCUSING BEYOND WELDS IN A PIPELINE
ULTRASONI GUIDED WAVE FOUSING BEYOND WELDS IN A PIPELINE Li Zhang, Wei Luo, Joseph L. Rose Department of Engineering Science & Mechanics, The Pennsylvania State University, University Park, PA 1682 ABSTRAT.
More informationThe Naim Balanced Mode Radiator The Naim Ovator Bass Driver
1 The Naim Balanced Mode Radiator The Naim Ovator Bass Driver Lampos Ferekidis & Karl-Heinz Fink Fink Audio Consulting on behalf of Naim Audio Southampton Road, Salisbury SP1 2LN, ENGLAND The Balanced
More informationPiezoelectric Sensors and Actuators
Piezoelectric Sensors and Actuators Outline Piezoelectricity Origin Polarization and depolarization Mathematical expression of piezoelectricity Piezoelectric coefficient matrix Cantilever piezoelectric
More informationAcoustic Emission Signals versus Propagation Direction for Hybrid Composite Layup with Large Stiffness Differences versus Direction
31 st Conference of the European Working Group on Acoustic Emission (EWGAE) We.1.A.1 More Info at Open Access Database www.ndt.net/?id=17568 Acoustic Emission Signals versus Propagation Direction for Hybrid
More informationFUNDAMENTALS OF ACOUSTICS
FUNDAMENTALS OF ACOUSTICS Fourth Edition LAWRENCE E. KINSLER Late Professor Emeritus Naval Postgraduate School AUSTIN R. FREY Late Professor Emeritus Naval Postgraduate School ALAN B. COPPENS Black Mountain
More informationAspects Regarding the Resonance Frequencies of Guitar Bodies with Different Strutting Systems
5 th International Vilnius Conference EURO Mini Conference Knowledge-Based Technologies and OR Methodologies for Strategic Decisions of Sustainable Development (KORSD-2009) September 30 October 3, 2009,
More informationAbaqus/CAE (ver. 6.14*) Plate/Shell Tutorial
Abaqus/CAE (ver. 6.14*) Plate/Shell Tutorial Problem Description The aluminum arch (E = 79 GPa, ν = 0.33) shown below is completely clamped along the flat faces. The arch supports a pressure of 100 MPa.
More informationReview of AISI Design Guide for Cold-formed Steel Purlin Roof Framing Systems-component Stiffness Method
Missouri University of Science and Technology Scholars' Mine International Specialty Conference on Cold- Formed Steel Structures (2010) - 20th International Specialty Conference on Cold-Formed Steel Structures
More information