Ice-structure impact contact load test setup and impact contact load calculation

Aki Kinnunen, Maria Tikanmäki, Pekka Koskinen

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientificpeer-review

Abstract

Shipping in arctic and other ice conditions is increasing. Modern propulsion systems often utilize azimuthing thrusters in their various forms. When operating azimuthing thruster equipped ships in ice conditions, the thruster will interact with ice. One such interaction type is an impact type contact of ice block and thruster. The contact causes certain loading to thruster. The contact load problem can be considered as ice impact to steel structure. In a research project related to developing Finnish-Swedish ice class rules, the impact forces due to ice contact to steel structure are dealt with a simple theoretical model and experimental approach is used for model validation. In this paper, the experiment setup and result examples are presented. The experimental setup presented was used for studying the contact force during an impact type contact. Impacts were hit to solid ice and floating ice block, contact point was submerged. The test device is representing a ship and thruster structure, and is laboratory scale equipment. The test device is a pendulum mass with changeable impact contact head. The device provides impact contact load measurement, pendulum motion measurement and the ice movement measurement. In addition, synchronized video recording was made. Tests were performed on sea ice during March 2013. The speed range capability for the test device is representative for ship speed in ice channel operation. In the tests, impact energy was varied by varying the pendulum start level. Two sizes of hemispherical contact geometries were used. Test results indicate distribution of energy in the impact event, i.e. ice kinetic energy, impacting mass kinetic energy and the rest is assumed to be drag and ice crushing energy. The test setup can very simply be tuned to different dynamic state to represent different stiffness of thruster installation to ship, and it can accommodate different contact geometries.
Original languageEnglish
Title of host publicationConference proceedings
Subtitle of host publication22nd IAHR International Symposium on Ice, 2014
Place of PublicationSingapore
PublisherNanyang Technological University
Number of pages8
ISBN (Print)978-981-09-0750-1
Publication statusPublished - 2014
MoE publication typeA4 Article in a conference publication
Event22nd IAHR International Symposium on Ice, ICE 2014 - Singapore, China
Duration: 11 Aug 201415 Aug 2014

Conference

Conference22nd IAHR International Symposium on Ice, ICE 2014
Abbreviated titleICE 2014
CountryChina
CitySingapore
Period11/08/1415/08/14

Fingerprint

Ice
Ships
Pendulums
Steel structures
Kinetic energy
Video recording
Sea ice
Geometry
Point contacts
Crushing
Freight transportation
Propulsion
Drag
Stiffness

Keywords

  • azimuth thrusters
  • ice loads
  • marine propulsion
  • ships

Cite this

Kinnunen, A., Tikanmäki, M., & Koskinen, P. (2014). Ice-structure impact contact load test setup and impact contact load calculation. In Conference proceedings: 22nd IAHR International Symposium on Ice, 2014 Singapore: Nanyang Technological University.
Kinnunen, Aki ; Tikanmäki, Maria ; Koskinen, Pekka. / Ice-structure impact contact load test setup and impact contact load calculation. Conference proceedings: 22nd IAHR International Symposium on Ice, 2014. Singapore : Nanyang Technological University, 2014.
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abstract = "Shipping in arctic and other ice conditions is increasing. Modern propulsion systems often utilize azimuthing thrusters in their various forms. When operating azimuthing thruster equipped ships in ice conditions, the thruster will interact with ice. One such interaction type is an impact type contact of ice block and thruster. The contact causes certain loading to thruster. The contact load problem can be considered as ice impact to steel structure. In a research project related to developing Finnish-Swedish ice class rules, the impact forces due to ice contact to steel structure are dealt with a simple theoretical model and experimental approach is used for model validation. In this paper, the experiment setup and result examples are presented. The experimental setup presented was used for studying the contact force during an impact type contact. Impacts were hit to solid ice and floating ice block, contact point was submerged. The test device is representing a ship and thruster structure, and is laboratory scale equipment. The test device is a pendulum mass with changeable impact contact head. The device provides impact contact load measurement, pendulum motion measurement and the ice movement measurement. In addition, synchronized video recording was made. Tests were performed on sea ice during March 2013. The speed range capability for the test device is representative for ship speed in ice channel operation. In the tests, impact energy was varied by varying the pendulum start level. Two sizes of hemispherical contact geometries were used. Test results indicate distribution of energy in the impact event, i.e. ice kinetic energy, impacting mass kinetic energy and the rest is assumed to be drag and ice crushing energy. The test setup can very simply be tuned to different dynamic state to represent different stiffness of thruster installation to ship, and it can accommodate different contact geometries.",
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Kinnunen, A, Tikanmäki, M & Koskinen, P 2014, Ice-structure impact contact load test setup and impact contact load calculation. in Conference proceedings: 22nd IAHR International Symposium on Ice, 2014. Nanyang Technological University, Singapore, 22nd IAHR International Symposium on Ice, ICE 2014, Singapore, China, 11/08/14.

Ice-structure impact contact load test setup and impact contact load calculation. / Kinnunen, Aki; Tikanmäki, Maria; Koskinen, Pekka.

Conference proceedings: 22nd IAHR International Symposium on Ice, 2014. Singapore : Nanyang Technological University, 2014.

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientificpeer-review

TY - GEN

T1 - Ice-structure impact contact load test setup and impact contact load calculation

AU - Kinnunen, Aki

AU - Tikanmäki, Maria

AU - Koskinen, Pekka

N1 - Project code: 82347

PY - 2014

Y1 - 2014

N2 - Shipping in arctic and other ice conditions is increasing. Modern propulsion systems often utilize azimuthing thrusters in their various forms. When operating azimuthing thruster equipped ships in ice conditions, the thruster will interact with ice. One such interaction type is an impact type contact of ice block and thruster. The contact causes certain loading to thruster. The contact load problem can be considered as ice impact to steel structure. In a research project related to developing Finnish-Swedish ice class rules, the impact forces due to ice contact to steel structure are dealt with a simple theoretical model and experimental approach is used for model validation. In this paper, the experiment setup and result examples are presented. The experimental setup presented was used for studying the contact force during an impact type contact. Impacts were hit to solid ice and floating ice block, contact point was submerged. The test device is representing a ship and thruster structure, and is laboratory scale equipment. The test device is a pendulum mass with changeable impact contact head. The device provides impact contact load measurement, pendulum motion measurement and the ice movement measurement. In addition, synchronized video recording was made. Tests were performed on sea ice during March 2013. The speed range capability for the test device is representative for ship speed in ice channel operation. In the tests, impact energy was varied by varying the pendulum start level. Two sizes of hemispherical contact geometries were used. Test results indicate distribution of energy in the impact event, i.e. ice kinetic energy, impacting mass kinetic energy and the rest is assumed to be drag and ice crushing energy. The test setup can very simply be tuned to different dynamic state to represent different stiffness of thruster installation to ship, and it can accommodate different contact geometries.

AB - Shipping in arctic and other ice conditions is increasing. Modern propulsion systems often utilize azimuthing thrusters in their various forms. When operating azimuthing thruster equipped ships in ice conditions, the thruster will interact with ice. One such interaction type is an impact type contact of ice block and thruster. The contact causes certain loading to thruster. The contact load problem can be considered as ice impact to steel structure. In a research project related to developing Finnish-Swedish ice class rules, the impact forces due to ice contact to steel structure are dealt with a simple theoretical model and experimental approach is used for model validation. In this paper, the experiment setup and result examples are presented. The experimental setup presented was used for studying the contact force during an impact type contact. Impacts were hit to solid ice and floating ice block, contact point was submerged. The test device is representing a ship and thruster structure, and is laboratory scale equipment. The test device is a pendulum mass with changeable impact contact head. The device provides impact contact load measurement, pendulum motion measurement and the ice movement measurement. In addition, synchronized video recording was made. Tests were performed on sea ice during March 2013. The speed range capability for the test device is representative for ship speed in ice channel operation. In the tests, impact energy was varied by varying the pendulum start level. Two sizes of hemispherical contact geometries were used. Test results indicate distribution of energy in the impact event, i.e. ice kinetic energy, impacting mass kinetic energy and the rest is assumed to be drag and ice crushing energy. The test setup can very simply be tuned to different dynamic state to represent different stiffness of thruster installation to ship, and it can accommodate different contact geometries.

KW - azimuth thrusters

KW - ice loads

KW - marine propulsion

KW - ships

M3 - Conference article in proceedings

SN - 978-981-09-0750-1

BT - Conference proceedings

PB - Nanyang Technological University

CY - Singapore

ER -

Kinnunen A, Tikanmäki M, Koskinen P. Ice-structure impact contact load test setup and impact contact load calculation. In Conference proceedings: 22nd IAHR International Symposium on Ice, 2014. Singapore: Nanyang Technological University. 2014