Damage tolerance and structural monitoring for wind turbine blades

Abstract

The paper proposes a methodology for reliable design and maintenance of wind turbine rotor blades using a condition monitoring approach and a damage tolerance index coupling the material and structure. By improving the understanding of material properties that control damage propagation it will be possible to combine damage tolerant structural design, monitoring systems, inspection techniques and modelling to manage the life cycle of the structures. This will allow an efficient operation of the wind turbine in terms of load alleviation, limited maintenance and repair leading to a more effective exploitation of offshore wind.

Bayesian Estimation of Remaining Useful Life for Wind Turbine Blades

“…For real detected cracks in wind turbines blades, there are many uncertainties involved in determining these. Even though this approach can, in principle, be used for the prediction of crack growth [4], the difficulties in obtaining the relevant parameters can be hard to overcome. An option is to obtain the parameters by calibration of a fracture mechanics (FM) model to give same reliability as a function of time as obtained using the stress-cycle (S-N) curve approach in design [5], as have been done for risk-based inspection (RBI) planning for fatigue cracks in oil and gas structures [6].…”

New perspectives in offshore wind energy

“…In the theme issue, the papers by Kallehave et al [40], Byrne & Houlsby [41], McGugan et al [42], and Borg & Collu [43] are dedicated to these subjects.…”

“…A new design approach involving damage tolerant structural design and condition monitoring, with specific applications to improved design of blades, is proposed in the paper by McGugan et al [42]. In recognition of the fact that large 'perfect' blades are not possible to manufacture, that large blades with defects or damages are too costly to discard, and that manual inspection may be too expensive for offshore wind turbines, the authors propose an original design approach combining damage tolerant materials, built-in sensors to detect evolving damage, non-destructive experimental tests to characterize damage, and detailed FE structural models of damaged blades to estimate residual fatigue life and strength.…”

Materials for the 21st century: What will we dream up next?

“…A move toward 3D carbon fi ber fabrics so that the triaxial load can be fully optimized in the structure would improve performance, 50 as would the use of carbon-nanotube-based fi bers. 51 Technologies such as 3D knitting, imported from the fashion world, which can produce 3D woven structures, can be expected to fi nd their way into the production of these advanced composites.…”