In order to remain competitive in the marketplace, all motor vehicle
manufacturers face difficult decisions with regard to balancing cost vs. feature.
That is to say that the manufacturer must balance the cost of the product to the
customer to remain competitive whilst offering appropriate technology and
standard features required by that customer.
All motor manufacturers are therefore under pressure to keep costs of nonfeature
items to a minimum. One of the cost reductions items prevalent on most
vehicles is the deletion of the structural member that attaches the rear bumper,
known as the bumper beam (RBB), which is researched in this Thesis. This
generates average vehicle savings of $20 and, as this is invisible to the
customer, should enable the manufacturers to realise a significant saving or
allow this revenue to be spent on additional feature without loss of vehicle
function.
However, in nearly all cases, deletion of the rear bumper beam has the effect of
degrading the steering responses of the vehicle by 1 to 1½ rating points (out of
10), which is contrary to the premise of cost reductions; which is to ensure that
vehicle function is unaffected.
Initial analysis of vehicles with deleted rear bumper beams cannot show an
objective measurable difference in any vehicle behaviours with or without the beam fitted, and hence CAE studies using ADAMS models cannot verify the
effects of the bumper beam. It was necessary to employ unconventional
modelling and testing methods such as rigid body, flexible body model
techniques as well as experimental studies included driving robots and expert
driver appraisals.
The research demonstrated that vehicle modelling methods currently used,
cannot establish or predict the complete vehicle ride and handling status. A total
vehicle model approach should be used without separating the body CAE
model and vehicle dynamics ADAMS model into separate entities.
Furthermore, it was concluded that the determination to the effects of body
hysteresis rather than pure stiffness is of crucial importance and that the
steering attribute could be maintained with the deletion of the RBB analytically.
| Identifer | oai:union.ndltd.org:BRADFORD/oai:bradscholars.brad.ac.uk:10454/14405 |
| Date | January 2015 |
| Creators | Banks, Alan J. |
| Contributors | Day, Andrew J., Hussain, Khalid |
| Publisher | University of Bradford, Faculty of Engineering and Informatics Bradford Programme of Engineering Quality Improvement |
| Source Sets | Bradford Scholars |
| Language | English |
| Detected Language | English |
| Type | Thesis, doctoral, PhD |
| Rights | <a rel="license" href="http://creativecommons.org/licenses/by-nc-nd/3.0/"><img alt="Creative Commons License" style="border-width:0" src="http://i.creativecommons.org/l/by-nc-nd/3.0/88x31.png" /></a><br />The University of Bradford theses are licenced under a <a rel="license" href="http://creativecommons.org/licenses/by-nc-nd/3.0/">Creative Commons Licence</a>. |
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