A dissertation submitted to the Faculty of Engineering and the BuiltEnvironment,University of the Witwatersrand,Johannesburg,in fulfilment of the requirements for the degree of Master of Science in Engineering, 2019 / A Performance-based Standards(PBS) framework legislates the dynamic performance and road-width usage of heavy vehicles,allowing the length and mass of a vehicle to exceed prescriptive legislation.The PBS framework defines the safe performance envelope of vehicles but does not optimise their safety and productivity.The design process to achieve the optimal productivity of PBS vehicles is highly iterative.An initial design is evaluated using multi-body dynamic ssimulation.If the required PBS performance is not achieved,design iterationsare made until the required PBS performance is achieved.The process is costly,time-consuming andcomputationallyexpensive.Theobjectiveofthisresearchistoquantifytherelativeeffect ofeachVehicleDesignParameter(VDP)ofamulti-bodyvehicledynamicsmodelonthevehicle safetyasmeasuredwithinthePBSframeworktoassistinthePBSassessmentprocess.To achievethis,threerepresentativebaselinePBSvehiclesweredeveloped(aquadsemi-trailer, trideminterlinkandrigiddrawbarcombination)fromPBSassessmentsconductedinSouth Africa.AsetofrangeswithinwhicheachVDPcouldbevariedwasdevelopedbyconsidering OriginalEquipmentManufacturer(OEM)data,legalrestrictions,physicalconstraintsand SouthAfricanPBSassessments.EachVDPforeachbaselinecombinationwasvariedin isolationtoevaluateitsinfluenceonthevehiclesperformancewithinthePBSframework.A comparative matrix was developed for each baseline vehicle comparing the relative influence of each VDP on each of the PBS performance measures.The matrices yield insight into which VDP shave the most influence on each performance measure for each of the baseline vehicles.Furthermore VDPs that have an egligible influence on the performance of all baseline vehicles can be conservatively estimated in the absence of OEM data while still predicting representative vehicle performance.These insights will guide designers to focus onVDPs with a high influence on vehicle performance,allow PBS assessors to determine which design parameters can be modelled with generic approximate data in the absence of OEMdata,and speedup the process of assessing vehicles with in the PBS framework. / TL (2020)
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:wits/oai:wiredspace.wits.ac.za:10539/29435 |
| Date | January 2019 |
| Creators | Deiss, Jarryd Andre |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | Online resource (165 leaves), application/pdf, application/pdf |
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