Use this URL to cite or link to this record in EThOS:
Title: Gas loss and durability of EVA foams used in running shoes
Author: Verdejo, Raquel
ISNI:       0000 0001 3546 0507
Awarding Body: University of Birmingham
Current Institution: University of Birmingham
Date of Award: 2004
Availability of Full Text:
Access from EThOS:
Access from Institution:
Ageing mechanisms affect the thermal properties and creep response of polymericfoams. This research analyses the effects of gas diffusion on the mechanical responseof polymeric foams subjected to periodic loads and studies their durability.A repeat impact machine was developed to analyse changes in the mechanical responseof ethylene vinyl acetate copolymer foams used in running shoes. The equipmentshowed some advantages compared to the standard method used in runningshoes and produced reproducible results. The softening of the material with thedistance run and the reduction in the cushioning properties are mainly due to theyielding and unyielding of the cellular structure and not to a change in the air content. Midsole deterioration in running shoes was measured in controlled running tests.These confirmed the deterioration of the midsole foam, with an increase of the peakplantar pressure and structural damage in the foam after a long run.The diffusion coefficients of Ethylene-Vinyl Acetate (EVA) foams were measuredusing a microbalance where the pressure and the temperature were controlled. Theoreticalanalysis of gas diffusion in foams subjected to repeat impact was carried outand confirmed a negligible gas loss due to diffusion in foams under cyclic loads.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available
Keywords: T Technology (General)