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Monitoring and characterization of vibration and shock conditions aboard high-performance marine craft
KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Naval Systems.ORCID iD: 0000-0002-8931-2566
KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Naval Systems.ORCID iD: 0000-0002-9110-9401
2018 (English)In: Journal of Engineering for the Maritime Environment (Part M), ISSN 1475-0902, E-ISSN 2041-3084, Vol. 233, no 4, p. 1068-1081Article in journal (Refereed) Published
Abstract [en]

The stochastic environmental conditions together with craft design and operational characteristics make it difficult to predict the vibration environments aboard high-performance marine craft, particularly the risk of impact acceleration events and the shock component of the exposure often being associated with structural failure and human injuries. The different timescales and the magnitudes involved complicate the real-time analysis of vibration and shock conditions aboard these craft. The article introduces a new measure, severity index, indicating the risk of severe impact acceleration, and proposes a method for real-time feedback on the severity of impact exposure together with accumulated vibration exposure. The method analyzes the immediate 60s of vibration exposure history and computes the severity of impact exposure as for the present state based on severity index. The severity index probes the characteristic of the present acceleration stochastic process, that is, the risk of an upcoming heavy impact, and serves as an alert to the crew. The accumulated vibration exposure, important for mapping and logging the crew exposure, is determined by the ISO 2631:1997 vibration dose value. The severity due to the impact and accumulated vibration exposure is communicated to the crew every second as a color-coded indicator: green, yellow and red, representing low, medium and high, based on defined impact and dose limits. The severity index and feedback method are developed and validated by a data set of 27 three-hour simulations of a planning craft in irregular waves and verified for its feasibility in real-world applications by full-scale acceleration data recorded aboard high-speed planing craft in operation.

Place, publisher, year, edition, pages
UK: Institution of Mechanical Engineers, 2018. Vol. 233, no 4, p. 1068-1081
Keywords [en]
High-speed craft, Whole-body vibration, Repeated shock, Impact, Epidemiology, Extreme value
National Category
Engineering and Technology
Research subject
Vehicle and Maritime Engineering
Identifiers
URN: urn:nbn:se:kth:diva-260377DOI: 10.1177/1475090218810245ISI: 000486892600007Scopus ID: 2-s2.0-85059610722OAI: oai:DiVA.org:kth-260377DiVA, id: diva2:1355446
Note

This research is funded by the Gösta Lundeqvist foundation for ship research (Gösta Lundeqvists stiftelse för skeppsteknisk forskning) and the Swedish Maritime Administration (Sjöfartsverket). QC 20191001

Available from: 2019-09-28 Created: 2019-09-28 Last updated: 2022-06-26Bibliographically approved
In thesis
1. Towards consonance in working conditions, health and performance aboard high-performance marine craft
Open this publication in new window or tab >>Towards consonance in working conditions, health and performance aboard high-performance marine craft
2020 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The High-Performance Marine Craft (HPMC) is a complex man-machine system dealing with the stochastic nature of the sea. The occupants of these craft are challenged by the strenuous work environments resulting in various detrimental conditions and reducing the overall performance of the system. The sophisticated craft, designed and developed for high operational demands, are underused due to the human limitations while occupants confronting various psychophysical impairments. A balance is required between the craft and human to get the most out of the system as an ensemble. Achieving that, the knowledge is essential about the human response to the working conditions aboard HPMC which is lacking in the scientific community.

In this context, a research program has been commenced to investigate working conditions aboard HPMC and the response of the craft occupants in terms of health and performance. The thesis presents the research as a holistic approach to integrate the exposure-response relationship into HPMC design and operation.

An epidemiological study is designed and executed to identify and quantify the risk associated with the working conditions aboard HPMC. As the first step, two web-based questionnaire tools are developed, validated and pilot tested for cross-sectional and longitudinal investigation of health and performance in HPMC occupants. Then a sample of HPMC occupants is investigated for work-related and individual risk factors relating to their work-exposure, health and performance in a cross-sectional cohort study. The prevalence of health impairments and performance degradation is determined while estimating their association with work exposure. Following that, another sample of HPMC occupants is longitudinally examined in a prospective cohort study for their work exposure, health and performance estimating the incidence of adverse health effects and its association with the occupational exposure to shock and vibration. Finally, a method is developed for a decision support feedback system continuously updating the crew during real-time operations on the severity of expected high-intensity short-duration impacts as well as the accumulated vibration exposure aboard HPMC.

The cross-sectional study shows that the prevalence of musculoskeletal pain (MSP) among HPMC occupants is comparatively high and that the exposure to severe conditions aboard semi-displacement and planing craft increases the risk of MSP. The latter also increases the risk of performance degradation. The longitudinal study indicates an incidence of MSP and performance degradation in HPMC occupants. It also suggests that the accumulation of occupational exposure to shock and vibration aboard HPMC is a factor increasing the risk of MSP incidence while quantifying the level of risk. The introduced method for real-time crew feedback is capable of capturing the exposure severity and informing it to the crew in a sufficiently short time.

The research has successfully achieved the objectives. It has also highlighted the areas that need further improvements and suggested the domains that require extended investigations.

Abstract [sv]

Högprestandafartyg (HPMC) utgör ett komplicerat människa-maskin-system som opererar i  havets stokastiska vågmiljö. De som arbetar ombord utsätts för en påfrestande arbetsmiljö och riskfyllda förhållanden som påverkar systemets totala prestanda. Den sofistikerade tekniken konstruerad och utvecklad för höga driftskrav  underutnyttjats på grund av de mänskliga psyko-fysiskabegränsningarna. Balans krävs mellan fartyget och människan för att få ut det mesta av systemet som helhet. För att nå dit är kunskapen om hur människan reagerar på de speciella arbetsförhållandena ombord på HPMC väsentlig, vilket idag saknas i det vetenskapliga samfundet.

I detta kontext har ett forskningsprogram initierats för att undersöka arbetsförhållandena ombord på HPMC och hur besättnigens hälsa och arbetsförmåga påverkas. Avhandlingen presenterar forskningen som en holistisk strategi för att integrera exponerings-responsförhållandet både vid konstruktionen av HPMC och under drift.

En epidemiologisk studie är utformad och genomförd för att identifiera och kvantifiera risker i relation till arbetsförhållandena ombord på HPMC. Som det första steget, utvecklas två webbaserade frågeformulärverktyg, de valideras och pilotestas för tvärsnitts- och longitudinella studier av hälsa och prestation hos HPMC-besättningar. Därefter undersöks ett urval av HPMC-besättningarna med avseende på arbetsrelaterade och individuella riskfaktorer som rör deras exponering, hälsa och prestation i en tvärsnittskohortstudie. Förekomsten av nedsatt hälsa och försämrad prestationsförmåga bestäms samtidigt som man beräknar  effekternas samband med exponeringen. Därefter undersöks ytterligare en grupp av HPMC-besättningar longitudinellt i en prospektiv kohortstudie med avseende på exponering, hälsa och prestation för att uppskatta förekomsten av negativa hälsoeffekter och dessas koppling till exponering av stötar och vibrationer under deras yrkesutövande. Slutligen utvecklas en metod till ett återkopplande system som i realtid indikerar både risken för stötbelastningar och den akumulerade vibrationsexponering som beslutsstöd till besättningen under arbetet till sjöss.

Tvärsnittsstudien visar att prevalensen för muskuloskeletalsmärta (MSP) bland HPMC-besättningar är relativt hög och att hård exponering ombord på semi-planande och planande fartyg ökar risken för MSP, varav det senare fallet dessutom ökar risken för nedsatt arbetsprestation. Den longitudinella studien indikerar MSP incidens och prestationsdegradering hos HPMC-personer. Studien antyder också att den ackumulerade exponeringen för stötar och vibration ombord på HPMC är en faktor som ökar risken för MSP-incidens och kvantifierar risknivån. Den introducerade metoden för realtidsåterkoppling till besättningen kan fånga exponeringsnivån och informera besättningen tillräckligt snabbt för att de ska kunna vidta åtgärder.

Forskningen som presenteras i avhandlingen har uppnått målsättningarna. Den har också betonat de områden som behöver utvecklas ytterligare  och föreslagit vidare studier.

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2020. p. 51
Series
TRITA-SCI-FOU ; 2020:28
Keywords
high-speed craft, human factors, whole-body vibration, epidemiology, pain, fatigue, höghastighetsfartyg, mänskliga faktorn, helkroppsvibrationer, epidemiologi, smärta, trötthet
National Category
Vehicle and Aerospace Engineering
Research subject
Vehicle and Maritime Engineering
Identifiers
urn:nbn:se:kth:diva-279997 (URN)978-91-7873-635-5 (ISBN)
Public defence
2020-09-29, Room No: 132 (Code: F3) Live-streaming: Register in advance for this webinar: https://kth-se.zoom.us/webinar/register/WN_tvjwWwKySSCfNj1YyDqQ6A After registering, you will receive a confirmation email containing information about joining the webinar. If you lack computer or computerskills, contact Karl Garme at garme@kth.se, Lindstedtsvägen 26, Stockholm, 10:00 (English)
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Note

QC 20200902

Available from: 2020-09-02 Created: 2020-09-01 Last updated: 2025-02-14Bibliographically approved

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