Laser excitation system for measuring frequency response function of underwater structures

Naoki Hosoya, I. Kajiwara, K. Umenai

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Ocean robots that equipped with manipulator for building underwater structures and handling investigations of ocean resources have been studied. To achieve high-precision and high-speed positioning for the manipulator, its vibration caused by an additional mass effect of fluid, a drag force and a buoyant force, etc. should be evaluated by vibration tests in water in actual equipment and suppressed through this evaluation. However, the vibration tests of the underwater structures (we refer to machines and structures in water as underwater structures) to measure frequency response function are difficult. This paper proposes a method of a non-contact experimental vibration analysis using pulsed-laser ablation for the underwater structures that were completely submerged in water. The impact testing with impulse hammer is used widely for experimental vibration analysis due to the simplicity of the apparatus. However, the impact testing has limitations in use in underwater condition because it is difficult for experimenters to operate the impact hammer in water. The proposed method yields the frequency response functions by applying a pulsed-laser-ablation excitation force to the structure and measuring the output using a laser Doppler vibrometer. Since the direction, strength and effective duration of the pulsed-laser-ablation force are essentially constant, this force can be calibrated by measuring these properties in advance. Therefore input-detection-free frequency response function measurements can be realized. The results obtained in this study demonstrate the effectiveness of the present vibration test method for the underwater structures.

Original languageEnglish
Title of host publicationProceedings of ISMA 2014 - International Conference on Noise and Vibration Engineering and USD 2014 - International Conference on Uncertainty in Structural Dynamics
PublisherKU Leuven
Pages1089-1099
Number of pages11
ISBN (Print)9789073802919
Publication statusPublished - 2014
Event26th International Conference on Noise and Vibration Engineering, ISMA 2014, Including the 5th International Conference on Uncertainty in Structural Dynamics, USD 2014 - Leuven
Duration: 2014 Sep 152014 Sep 17

Other

Other26th International Conference on Noise and Vibration Engineering, ISMA 2014, Including the 5th International Conference on Uncertainty in Structural Dynamics, USD 2014
CityLeuven
Period14/9/1514/9/17

Fingerprint

underwater structures
Underwater structures
Laser excitation
frequency response
Frequency response
vibration tests
Laser ablation
Pulsed lasers
laser ablation
Impact testing
hammers
pulsed lasers
Hammers
excitation
lasers
Vibration analysis
vibration
water
Manipulators
Water

ASJC Scopus subject areas

  • Mechanical Engineering
  • Mechanics of Materials
  • Acoustics and Ultrasonics

Cite this

Hosoya, N., Kajiwara, I., & Umenai, K. (2014). Laser excitation system for measuring frequency response function of underwater structures. In Proceedings of ISMA 2014 - International Conference on Noise and Vibration Engineering and USD 2014 - International Conference on Uncertainty in Structural Dynamics (pp. 1089-1099). KU Leuven.

Laser excitation system for measuring frequency response function of underwater structures. / Hosoya, Naoki; Kajiwara, I.; Umenai, K.

Proceedings of ISMA 2014 - International Conference on Noise and Vibration Engineering and USD 2014 - International Conference on Uncertainty in Structural Dynamics. KU Leuven, 2014. p. 1089-1099.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Hosoya, N, Kajiwara, I & Umenai, K 2014, Laser excitation system for measuring frequency response function of underwater structures. in Proceedings of ISMA 2014 - International Conference on Noise and Vibration Engineering and USD 2014 - International Conference on Uncertainty in Structural Dynamics. KU Leuven, pp. 1089-1099, 26th International Conference on Noise and Vibration Engineering, ISMA 2014, Including the 5th International Conference on Uncertainty in Structural Dynamics, USD 2014, Leuven, 14/9/15.
Hosoya N, Kajiwara I, Umenai K. Laser excitation system for measuring frequency response function of underwater structures. In Proceedings of ISMA 2014 - International Conference on Noise and Vibration Engineering and USD 2014 - International Conference on Uncertainty in Structural Dynamics. KU Leuven. 2014. p. 1089-1099
Hosoya, Naoki ; Kajiwara, I. ; Umenai, K. / Laser excitation system for measuring frequency response function of underwater structures. Proceedings of ISMA 2014 - International Conference on Noise and Vibration Engineering and USD 2014 - International Conference on Uncertainty in Structural Dynamics. KU Leuven, 2014. pp. 1089-1099
@inproceedings{6db1b0a1537f4b25ba2cfc7895bc6ad4,
title = "Laser excitation system for measuring frequency response function of underwater structures",
abstract = "Ocean robots that equipped with manipulator for building underwater structures and handling investigations of ocean resources have been studied. To achieve high-precision and high-speed positioning for the manipulator, its vibration caused by an additional mass effect of fluid, a drag force and a buoyant force, etc. should be evaluated by vibration tests in water in actual equipment and suppressed through this evaluation. However, the vibration tests of the underwater structures (we refer to machines and structures in water as underwater structures) to measure frequency response function are difficult. This paper proposes a method of a non-contact experimental vibration analysis using pulsed-laser ablation for the underwater structures that were completely submerged in water. The impact testing with impulse hammer is used widely for experimental vibration analysis due to the simplicity of the apparatus. However, the impact testing has limitations in use in underwater condition because it is difficult for experimenters to operate the impact hammer in water. The proposed method yields the frequency response functions by applying a pulsed-laser-ablation excitation force to the structure and measuring the output using a laser Doppler vibrometer. Since the direction, strength and effective duration of the pulsed-laser-ablation force are essentially constant, this force can be calibrated by measuring these properties in advance. Therefore input-detection-free frequency response function measurements can be realized. The results obtained in this study demonstrate the effectiveness of the present vibration test method for the underwater structures.",
author = "Naoki Hosoya and I. Kajiwara and K. Umenai",
year = "2014",
language = "English",
isbn = "9789073802919",
pages = "1089--1099",
booktitle = "Proceedings of ISMA 2014 - International Conference on Noise and Vibration Engineering and USD 2014 - International Conference on Uncertainty in Structural Dynamics",
publisher = "KU Leuven",

}

TY - GEN

T1 - Laser excitation system for measuring frequency response function of underwater structures

AU - Hosoya, Naoki

AU - Kajiwara, I.

AU - Umenai, K.

PY - 2014

Y1 - 2014

N2 - Ocean robots that equipped with manipulator for building underwater structures and handling investigations of ocean resources have been studied. To achieve high-precision and high-speed positioning for the manipulator, its vibration caused by an additional mass effect of fluid, a drag force and a buoyant force, etc. should be evaluated by vibration tests in water in actual equipment and suppressed through this evaluation. However, the vibration tests of the underwater structures (we refer to machines and structures in water as underwater structures) to measure frequency response function are difficult. This paper proposes a method of a non-contact experimental vibration analysis using pulsed-laser ablation for the underwater structures that were completely submerged in water. The impact testing with impulse hammer is used widely for experimental vibration analysis due to the simplicity of the apparatus. However, the impact testing has limitations in use in underwater condition because it is difficult for experimenters to operate the impact hammer in water. The proposed method yields the frequency response functions by applying a pulsed-laser-ablation excitation force to the structure and measuring the output using a laser Doppler vibrometer. Since the direction, strength and effective duration of the pulsed-laser-ablation force are essentially constant, this force can be calibrated by measuring these properties in advance. Therefore input-detection-free frequency response function measurements can be realized. The results obtained in this study demonstrate the effectiveness of the present vibration test method for the underwater structures.

AB - Ocean robots that equipped with manipulator for building underwater structures and handling investigations of ocean resources have been studied. To achieve high-precision and high-speed positioning for the manipulator, its vibration caused by an additional mass effect of fluid, a drag force and a buoyant force, etc. should be evaluated by vibration tests in water in actual equipment and suppressed through this evaluation. However, the vibration tests of the underwater structures (we refer to machines and structures in water as underwater structures) to measure frequency response function are difficult. This paper proposes a method of a non-contact experimental vibration analysis using pulsed-laser ablation for the underwater structures that were completely submerged in water. The impact testing with impulse hammer is used widely for experimental vibration analysis due to the simplicity of the apparatus. However, the impact testing has limitations in use in underwater condition because it is difficult for experimenters to operate the impact hammer in water. The proposed method yields the frequency response functions by applying a pulsed-laser-ablation excitation force to the structure and measuring the output using a laser Doppler vibrometer. Since the direction, strength and effective duration of the pulsed-laser-ablation force are essentially constant, this force can be calibrated by measuring these properties in advance. Therefore input-detection-free frequency response function measurements can be realized. The results obtained in this study demonstrate the effectiveness of the present vibration test method for the underwater structures.

UR - http://www.scopus.com/inward/record.url?scp=84913582210&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84913582210&partnerID=8YFLogxK

M3 - Conference contribution

AN - SCOPUS:84913582210

SN - 9789073802919

SP - 1089

EP - 1099

BT - Proceedings of ISMA 2014 - International Conference on Noise and Vibration Engineering and USD 2014 - International Conference on Uncertainty in Structural Dynamics

PB - KU Leuven

ER -