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Stochastic transfer operator methods for modelling the vibroacoustic properties of newly emerging transport structures

Unit(s) of assessment: General Engineering

School: School of Science and Technology


This project aims to develop stochastic propagation models of vibroacoustic energy transport in complex and uncertain structures.

Funding Scheme: EPSRC First Grant

Value: £91,532

Duration: 12 months (start date: 1 April 2016)

The rapid growth of computing power during the last 50 years has given rise to a whole simulation industry serving the needs of the manufacturers looking to design products in an optimal manner, without the time and costs associated with building a series of physical prototypes. Design and construction decisions are increasingly made by means of virtual prototyping as part of Computer Aided Engineering (CAE). Noise and vibration are particularly important performance aspects in the design of many mechanical systems. High noise and vibration levels can be damaging to structures and to their users (potentially causing hearing loss, for example). Developing computational techniques to improve our understanding of the vibration and acoustics of complex built-up structures can enhance performance, speed up the design cycle and ultimately result in safer and less noisy products.

The sheer size and complexity of many transport structures such as aircraft, trains and cars makes building full-scale physical prototypes expensive, and often infeasible. It also poses problems for simulation methods and limits many CAE products to low frequencies, where computational run times are relatively low and uncertainties have little influence on the vibrational behaviour. Uncertainties arising during the manufacturing process (for example, in material properties or physical dimensions) can lead to large variations in the levels of noise and vibration of a structure at high frequencies, and so mechanical engineers often prefer statistical methods to instead predict averages of these noise and vibration levels. Unfortunately, these statistical methods are based on a set of assumptions that are hard to control and generally only fulfilled for more traditional structural designs. They are not fulfilled for the large curved and moulded components used today. Therefore the CAE tools available at present for simulating mid- and high- frequency noise and vibration do not meet the needs of engineers in the transport sector.

In this project, random (or stochastic) transfer operator methods will be developed for modelling mid-to-high frequency structural vibrations in large complex structures. These methods will have the advantages of the current statistical approaches in terms of being able to model uncertainties in the structural design and materials, but crucially will be applicable to a far wider range of structures, including large moulded components and novel lightweight materials. The approach to be developed therefore has the potential to form the basis of a black-box design tool for mechanical engineers looking to develop the next generation of green and lightweight transport structures.


The project is funded by the EPSRC under grant number EP/M027201/1 and will be led by NTU working in collaboration with software company PACSYS Ltd and composite materials developers Far-UK Ltd.