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Projects: Projects for Investigator
Reference Number EP/F02861X/1
Title 3-D strain field mapping of scattering media using Wavelength Scanning Interferometry with application to damaged composites
Status Completed
Energy Categories Renewable Energy Sources(Wind Energy) 10%;
Not Energy Related 90%;
Research Types Basic and strategic applied research 100%
Science and Technology Fields PHYSICAL SCIENCES AND MATHEMATICS (Metallurgy and Materials) 50%;
ENGINEERING AND TECHNOLOGY (Mechanical, Aeronautical and Manufacturing Engineering) 50%;
UKERC Cross Cutting Characterisation Not Cross-cutting 100%
Principal Investigator Professor JM Huntley
No email address given
Sch of Mechanical and Manufacturing Eng
Loughborough University
Award Type Standard
Funding Source EPSRC
Start Date 01 October 2008
End Date 30 September 2011
Duration 36 months
Total Grant Value £425,305
Industrial Sectors No relevance to Underpinning Sectors
Region East Midlands
Programme NC : Engineering
 
Investigators Principal Investigator Professor JM Huntley , Sch of Mechanical and Manufacturing Eng, Loughborough University (99.996%)
  Other Investigator Dr JM Coupland , Sch of Mechanical and Manufacturing Eng, Loughborough University (0.001%)
Dr PD Ruiz , Sch of Mechanical and Manufacturing Eng, Loughborough University (0.001%)
Dr G Zhou , Aeronautical and Automotive Engineering, Loughborough University (0.001%)
Dr IA (Ian ) Ashcroft , Mechanical, Materials and Manufacturing Engineering, University of Nottingham (0.001%)
  Industrial Collaborator Project Contact , Airbus UK Ltd (0.000%)
Project Contact , École Nationale Supérieure d’Arts et Métiers (Lille), France (0.000%)
Web Site
Objectives
Abstract The measurement of displacement and strain fields within polymers and composites is technically very challenging, yet is vital for the development of improved damage and failure models. One of the main techniques for 3-D strain measurement, neutron diffraction, is not generally applicable to these types of material and furthermore has poor spatial resolution (typically 1 mm or worse). In this project we aim to develop an optical technique, called wavelength scanning interferometry (WSI), to measure volume 3-D displacement fields to interferometric precision (~ 10 nm) and with spatial resolution of order 0.01 mm. The technique uses the phase measuring (including phase unwrapping) capabilities developed in the speckle interferometry community over the past 20 years but the wavelength scanning approach provides volume fields as opposed to the restriction to surface fields imposed by traditional speckle interferometry. Following construction of the multi-camera prototype instrument and development of phase volume reconstruction and registration software, validation will be achieved through the use of homogeneous polymeric samples in standard loading geometries, and with more realistic materials (glass fibre composites) containing embedded optical fibre strain sensors. After validation, the system will be applied to the measurement of volume displacement and strain fields within composite samples prepared with a range of controlled damaged states.In parallel to the optical system development and validation, a numerical program of work will focus on finite element modelling (FEM) of the damaged samples, and implementation of a novel 'inverse finite element analysis' technique called the virtual fields method (VFM). The VFM has recently been extended to three dimensions and allows distributions of modulus - the key to developing improved damage mechanics models - to be calculated directly from full-field displacement data, as opposed to the iterative approach required by FEM. The VFM is however relatively immature compared to FEM; a side by side comparison of the two approaches using experimental data from WSI is therefore essential to the future development of the VFM as a tool for structural engineers. As a result of this project, experimentally-determined high-resolution 3-D maps of the damage in these materials will be available for the first time, together with the effect of this damage on the load bearing capability of the damaged area. This data is essential for the development of robust, physically accurate strength and lifetime prediction for these increasingly important structural materials
Publications (none)
Final Report (none)
Added to Database 08/01/08