An Improved Method for Simulation of Vehicle Vibration Using a Journey Database and Wavelet Analysis for the Pre-Distribution Testing of Packaging

Abstract

Vehicle vibration is inherently random and non-stationary with a non-Gaussiandistribution. In addition, variations in vehicle parameters, product payloads anddistribution journeys mean that the characteristics of vibration are not identical forall distribution journeys. Because vehicle vibration and shock are key causes ofdamage during distribution, their simulation in pre-distribution testing is vital inorder to ensure that adequate protection is provided for transported products.The established method set out in the current testing standards utilises a global setof averaged accelerated power spectral density spectra to construct randomvibration signals. These signals are stationary with Gaussian distributions and,therefore, do not fully represent actual vehicle vibration, only an average.The aim of the investigation, reported on in this Thesis, was to create an improvedtest regime for simulating vehicle vibration for pre-distribution testing ofpackaging. This aim has been achieved through the construction of representativetests and the creation of realistic simulations with statistical significance.A journey database has been created, in which historic road profile data along witha quarter vehicle model have been used to approximate a known vehicle’svibration on a specific distribution journey. Additionally, a wavelet decompositionmethod, in which wavelet analysis is used to decompose the approximate vehiclevibration in to a series of Gaussian approximations of varying amplitude andspectral content, has been developed. Along with theoretical work, case studieshave been undertaken in order to validate the test regime.

Date of Award	30 Apr 2013
Original language	English
Awarding Institution	University of Bath
Supervisor	Ben Hicks (Supervisor) & Patrick Keogh (Supervisor)