Document Type : Original Article

Authors

1 Faculty of New Sciences and Technologies

2 Fracture Research Laboratory, Faculty of New Science and Technologies, University of Tehran

3 Department of Aerospace Engineering, Faculty of New Sciences and Technologies, University of Tehran

10.22034/jast.2018.145165

Abstract

In this paper, damage in composite wings is introduced, firstly, then using Euler- Bernoulli equations with including flexural and torsional coupling, governing equations on cantilevered composite wing is derived. By applying separation method damaged beam is converted to two interconnected intact beams and using boundary conditions and continues conditions in damage location, the dynamic stiffness matrix is composed and modal analysis of damaged wing is done. Composite type is fiber-reinforced and damage type is edge crack with various locations and depths. Also effects crack depths and locations on modal properties in various fiber angle are examined. Results showed that existence a crack even with small depth in root of large span wing can reduce natural frequencies, seriously.

Keywords

Article Title [فارسی]

Dynamic stiffness matrix for analysis of modal properties the damaged composite wing

Authors [فارسی]

  • Shahrokh Shams 1
  • A.R. Torabi 2
  • Mahdi Fathi Narab 3

1 Faculty of New Sciences and Technologies

2 Fracture Research Laboratory, Faculty of New Science and Technologies, University of Tehran

3 Department of Aerospace Engineering, Faculty of New Sciences and Technologies, University of Tehran

Abstract [فارسی]

In this paper, damage in composite wings is introduced, firstly, then using Euler- Bernoulli equations with including flexural and torsional coupling, governing equations on cantilevered composite wing is derived. By applying separation method damaged beam is converted to two interconnected intact beams and using boundary conditions and continues conditions in damage location, the dynamic stiffness matrix is composed and modal analysis of damaged wing is done. Composite type is fiber-reinforced and damage type is edge crack with various locations and depths. Also effects crack depths and locations on modal properties in various fiber angle are examined. Results showed that existence a crack even with small depth in root of large span wing can reduce natural frequencies, seriously.

Keywords [فارسی]

  • “Cracked wing”
  • “Dynamic stiffness matrix”
  • “Modal properties”
  • “interconnected beam”
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