Concurrent engineering approach to complete non-linear FEA of an aircraft wheel's lock-ring
Butcher, Kent (2012) Concurrent engineering approach to complete non-linear FEA of an aircraft wheel's lock-ring. PhD thesis, University of Warwick.Full text not available from this repository.
Official URL: http://webcat.warwick.ac.uk/record=b2581592~S1
This thesis presents a new finite element analysis (FEA) method for
calculating the critical stress in an aircraft wheel’s lock-ring. The lock-ring is
used on many modern designs in place of the bolts that join the two main
sections of the wheel. The lock-ring is a safety critical component of the
wheel as a failure could lead to an explosive release of tyre pressure. The
stress field in this wheel forms a fatigue cycle as the wheel rotates when the
aircraft manoeuvres on the ground. The stress field at the critical location on
the lock-ring is strongly dependent on the contacting surfaces of three
structural components of the wheel: the main hub, the lock-ring and the freeflange.
Until completion of this work no method existed to calculate the
fatigue stress cycle at this design critical location.
Modern wheel designs, to minimise aircraft weight and therefore fuel use, are
of minimum weight designs. This means that the aluminium material in the
latest wheel designs is subjected to greater stress than in previous designs,
therefore the ‘margin of safety’ for the wheels is reduced. It is important that
methods are developed to calculate the stress in all regions of the wheel,
including the lock-ring.
Lock-ring wheel designs were originally used on military aircraft and more
recently they have become common on business jet aircraft. Very recently
the feasibility of their use on large commercial aircraft that carry upwards of
100 passengers is being considered. The operating environment on large
commercial aircraft is very harsh for wheels and the methodology developed
in this work is required to correctly assess the use of these wheels in this
harsh and safety critical environment.
The calculation method is compared against physical test data measured on
two wheels using strain gauges. The wheels, with tyres installed, were loaded
and rolled on a road wheel dynamometer to simulate aircraft ground
manoeuvres. Measuring the critical location is difficult as access to it is
limited; it had not been measured before. The measured data are used to
verify the new FEA method.
The new FEA method was developed with the potential for use by both a nonspecialist
engineer and use in a modern Concurrent Engineering environment
as requirements. The FEA is linked directly to the CATIA 3D computer aided
design (CAD) model, using CADNexus software. This link is made in such a
way that a modification to the design, once included in the CAD model, can be
easily and automatically followed by an update to the FEA.
The FEA requires solution of a non-linear model because contact between
three structural components is critical and therefore must be modelled in
detail. The general perception in industry is that non-linear FEA is a complex
subject and must be undertaken by an experienced FEA specialist – this work
provides strong supportive evidence to contradict this general perception.
The FEA itself is implemented using ANSYS® Workbench software. The new
analysis method, including the model set-up parameters is stored in an
analysis template. This analysis template effectively captures the knowledge
of a specialist FEA engineer so that it can be used, for design purposes, by a
The final FEA method is useful not only to non-specialist engineers but also,
because the specialist knowledge is contained within the ANSYS®
Workbench template, for outsourcing this structural analysis work to lower
The works creates a new FEA method of specific use to manufactures and
designers of weight optimised aerospace wheels. Furthermore, in a more
general context, it demonstrates that even complex non-linear FEA can be
defined within knowledge capturing templates. This makes it accessible to
engineers without specialist expertise with FEA. Empowering the design
engineer to structurally optimise their own designs will lead to leaner design
teams, which will consequently reduce development costs. The new method
can be competed as part of a Concurrent Engineering process. This is
advantageous as it can expedite the design process, therefore allowing FEA
results to be available early enough in the programme to be made use of.
|Item Type:||Thesis or Dissertation (PhD)|
|Subjects:||T Technology > TL Motor vehicles. Aeronautics. Astronautics|
|Library of Congress Subject Headings (LCSH):||Finite element method, Airplanes -- Landing gear -- Design|
|Official Date:||March 2012|
|Institution:||University of Warwick|
|Theses Department:||School of Engineering|
|Supervisor(s)/Advisor:||Mottram, J. Toby (James Toby), 1958-|
|Extent:||x, 240 leaves : ill.|
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