The objective of this two year project is to develop methodology for non-destructive testing (NDT) and condition monitoring of composite materials.
The combined NDT methodology will have wide ranging application to composite materials, not only to wind turbine blades but also to many other engineering problems.
This project was highly successful and results show that the three non-destructive testing methodologies developed, when combined and analysed together, have the potential to extract more information than that obtainable using the individual techniques in isolation. The thermodynamic variables acting when materials are fatigued have therefore been unravelled and analysed in order to gain insight into the nature of the fatigue and damage process. A generic methodology for condition monitoring of wind turbine blades has therefore been developed and these NDT methodologies were also able to extract information on non-linear visco-elasticity thermo-visco-elasticity and combined 3D properties.
The methodology will include the use of several measurement techniques using synergy to extract additional information about the properties of the composite. Non-destructive testing is an emerging science and the level of expertise varies throughout Europe. This JOULE II project provides a suitable forum to bring together some of this expertise in order to coherently advance the field of NDT for composite materials.
Contact and non-contact methods will be used in the experiments. A comprehensive set of mechanical and thermal time series measurements will permit testing of the detailed properties of the composite material and their determination for the life cycle of the specimens. The findings for those measurements will allow individual condition monitoring techniques to be assessed, the development of a combined methodology and non-contact measuring techniques to be calibrated in a quantitative manner. In the initial phase, the specimens will be test coupons of wood laminate or glass/polyester. These will be produced by commercial manufacturers; one batch will be to their normal specifications and another batch will be produced with known defects. The fatigue testing of simple specimens at specific, analytic load cases will be undertaken in cooperation between all the institutions involved. Novel time series methods will be used to extract the thermal and mechanical transport properties and these will be related to the fundamental properties of the composite materials. The findings of the test coupon stage will be analysed and all groups will collaborate on the development of a combined condition monitoring and NDT methodology. The utility of the combined NDT methodology will be demonstrated firstly by the fatigue testing of plate specimens and finally on a full scale blade test. The life cycle characteristics of the plates will be monitored and the limitations of the various methodologies established. Proof of concept for combined condition monitoring methodology will be performed in a full blade test. The combined NDT methodology will have wide ranging application to composite materials, not only to wind turbine blades but also to many other engineering problems.
Funding SchemeCSC - Cost-sharing contracts
7550 AN Hengelo
EC1V 0HB London
2628 BL Delft
NG7 2RD Nottingham