Human responses to wave-induced motion, slamming and whipping.

dc.contributor.advisorBekker, Aen_ZA
dc.contributor.authorEngelbrecht, MCen_ZA
dc.contributor.otherStellenbosch University. Faculty of Engineering. Dept. of Mechanical and Mechatronic Engineering.en_ZA
dc.date.accessioned2023-11-23T18:18:57Zen_ZA
dc.date.accessioned2024-01-08T20:26:27Zen_ZA
dc.date.available2023-11-23T18:18:57Zen_ZA
dc.date.available2024-01-08T20:26:27Zen_ZA
dc.date.issued2023-11en_ZA
dc.descriptionThesis (MEng)--Stellenbosch University, 2023.en_ZA
dc.description.abstractENGLISH ABSTRACT: Ship motion is known to a ect comfort, rest and productivity. On ships, these factors could in uence fatigue-related accidents. Discomfort on cruise ships could adversely a ect customer satisfaction. The crew and passengers of vessels, live and work in this dynamic environment, often for months on end. Research regarding human comfort, as a result of impulsive wave slamming is specifically limited. Wave slamming is the random impact of waves against the ship hull leading to the phenomenon called whipping which causes vibration to propagate through the ship structure. This study investigated the effects of impulsive vibration on activity disturbance in the operational context of a slamming-prone vessel. Metrics from whole-body vibration standards were investigated as a possible means to quantify comfort. A possible threshold of the onset of discomfort was determined and compared to likely responses to whole-body vibration as documented in whole-body vibration standards, maritime standards and ship classification society documents. Subjective data was obtained from daily diary surveys conducted willingly by people on board. Additional human responses were reaped from instantaneous slam observations which were conducted from the Bridge during designated ship manoeuvres. Full-scale vibration measurements were recorded at several locations across the ship for the entire duration of the voyage and expressed in terms of metrics as provided in standards. Subjective and objective data were correlated. Subjective results show that slamming was prevalent on most days during investigated voyages. Sleeping was observed to be the activity most disturbed. Metrics such as vibration dose value and root-mean-square value had displayed positive strong correlations with the human response data. An hourly vibration dose value threshold of approximately 0.43 m/s1:75 and 0.47 m/s1:75 resulted from both the surveys and instantaneous slam ratings. This corresponds to the threshold where 50% of the sample population felt discomfort. The determined threshold for root-mean-square value of 0.03 m/s2 is much lower than guideline values provided in ISO 2631-1 for discomfort in public transport applications.en_ZA
dc.description.abstractAFRIKAANSE OPSOMMING: Dit is bekend dat skeepsbeweging die gemak, rus en produktiwiteit van mense beïnvloed. Op skepe kan hierdie faktore 'n invloed hê op ongelukke wat verband hou met moegheid. Ongemak op passasiersbote beïnvloed kliïntetevredenheid nadelig. Die bemanning en passasiers van vaartuie woon en werk in hierdie dinamiese omgewing, dikwels vir maande aaneen. Navorsing rakende menslike gemak, as gevolg van impulsiewe branderklap, is spesi ek beperk. Branderklap is die willekeurige impak van golwe teen die skip romp, dit lei tot die verskynsel genaamd sweep vibrasie wat die oordrag is van vibrasie deur die skipstruktuur. Hierdie studie het die gevolge van impulsiewe vibrasie op aktiwiteitsversteuring in die operasionele konteks van 'n skip ondersoek wat geneig is tot branderimpakte. Maatstawe uit heelligaam vibrasie-standaarde is ondersoek as 'n moontlike manier om gemak te kwanti seer. 'n Moontlike drempel vir die aanvang van ongemak is bepaal en vergelyk met waarskynlike reaksies op die heelliggaam vibrasie, soos gedokumenteer in die heelligaam vibrasie standaarde, maritieme standaarde en dokumente van die skeepsklassi kasieverenigings. Subjektiewe data is verkry uit daaglikse dagboekopnames wat gewillig deur mense aan boord ingevul is. Bykomende reaksies van die mens is geput uit oombliklike branderklap observasies wat vanaf die brug uitgevoer is tydens sistematiese skeepsmaneuvers. Volledige vibrasiemetings is gedurende die hele reis op verskillende plekke regoor die skip opgeneem en uitgedruk in terme van maatstawwe soos uiteengesit in standaarde. Subjektiewe en objektiewe data is gekorreleer. Slaap is die aktiwiteit wat die meeste tydens alle reise versteur word. Maatstawwe soos vibrasie-dosiswaarde en wortel-gemiddeldekwadraatwaarde het positiewe sterk korrelasies met die menslike responsdata getoon. Daar is gevind dat 'n uurlikse vibrasie-dosiswaarde van ongeveer 0.43 m/s1:75 en 0.47 m/s1:75 uit beide die opnames en die onmiddellike branderklap obserwasies, die drempel is waar 50% van die steekproefpopulasie ongemaklik voel. Die vasgestelde drempelwaarde vir wortel-gemiddelde-kwadraatwaarde van 0,03 m/s2 is baie laer as die riglyn waardes in ISO 2631-1 wat redvan toepassing is op publieke vervoer toepassings.af_ZA
dc.description.versionMasters.en_ZA
dc.format.extentx, 116 pages : illustrationsen_ZA
dc.identifier.urihttps://scholar.sun.ac.za/handle/10019.1/129046en_ZA
dc.language.isoen_ZAen_ZA
dc.language.isoen_ZAen_ZA
dc.publisherStellenbosch : Stellenbosch Universityen_ZA
dc.rights.holderStellenbosch Universityen_ZA
dc.subject.lcshShips -- Hydrodynamics en_ZA
dc.subject.lcshWave-motion, Theory ofen_ZA
dc.subject.lcshWave-induced slammingen_ZA
dc.subject.lcshVibration (Marine engineering)en_ZA
dc.titleHuman responses to wave-induced motion, slamming and whipping.en_ZA
dc.typeThesisen_ZA
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