文档介绍：1
COMPOSITE MATERIALS FATIGUE ISSUES IN WIND
TURBINE BLADE CONSTRUCTION
John F. Mandell, Daniel D. Samborsky, and Pancasatya Agastra
Department of Chemical and Biological Engineering, Montana State University,
Bozeman, MT 59717
ABSTRACT
This paper provides an overview of the results of recent studies posite laminates of
interest for wind turbine blade construction. In addition to the primary requirements of stiffness,
strength, and ease of processing, wind blade materials must withstand severe fatigue loading
under service environments. The large material volumes and cost constraints also lead to
unusually thick plies and fabrics, as well as thick adhesive bonds, which, combined with
relatively brittle, low cost resins, can exacerbate delamination related structural integrity issues
found in posites structures. Important differences in performance are shown for the
major fiber and resin types of relevance to blades. Details of fabric construction, fiber content
and ply drop and geometry can produce major differences in performance, particularly under
fatigue loading. Materials and conditions are identified where particularly low strain damage
failure can occur at high cycles.
KEY WORDS: Fatigue, Wind Turbine Blade Technology, Glass posites, Carbon
posites
1. INTRODUCTION
Wind turbine blades are designed to several major structural conditions, including tip deflection,
strength and buckling during severe loading, as well as very high numbers of fatigue cycles
during operation, varying between tension, compression and reversed pression loads
according to the particular loads spectrum for the turbine and wind conditions. The major static
strength and stiffness properties depend primarily on fiber type, content, and orientation,
posite mechanics predictions widely available in the literature. The fatigue of
composite laminates appropriate for wind turbine blades has been the to