Skip to main content
Article thumbnail
Location of Repository

Design and Modeling of Selective Reinforcements for Integral Aircraft Structures

By M. Boscolo, Giuliano Allegri and Xiang Zhang

Abstract

A numerical simulation is presented in this paper on the performance of crack retarders bonded to integral metallic structures. The work is described in two main parts. First, a novel modeling approach employing the finite element method has been developed for simulating the various failure mechanisms of a bonded structure and for predicting fatigue crack growth life. Crack growth in the substrate and the substrate/strap interface disbond failure are modeled in the framework of linear elastic fracture mechanics. A computer code interfacing with the commercial package MSC NASTRAN has been developed and validated by experimental tests. Second, the effectiveness of different strap configurations on crack growth retardation has been modeled; these include different strap materials, strap dimensions, and their locations on the substrate. The research has included two substrate materials and four strap materials, and at this stage the specimens were cured at room temperature. Strap stiffness and adhesive toughness are found to be the most influential parameters in designing crack retarders. A design tool has been developed based on the numerical simulation to achieve optimal crack retarder design in terms of prescribed fatigue life target and minimum structural weight added by the bonded reinforcement

Publisher: American Inst of Aeronautics and Astronautics
Year: 2008
DOI identifier: 10.2514/1.35712
OAI identifier: oai:dspace.lib.cranfield.ac.uk:1826/3105
Provided by: Cranfield CERES
Journal:

Suggested articles

Citations

  1. (1982). A Cracked Plate Repaired by Bonded Reinforcements,” doi
  2. (1963). A Critical Analysis of Crack Propagation Laws,” doi
  3. (2006). Adhesively Bonded CFRP Straps as Fatigue Crack Growth Retarders on
  4. (2006). AFGROW Users Guide and Technical Manual,” Air Vehicles Directorate, http://www.siresearch.info/projects/afgrow/ downloads/afgrow/ddownload.php,
  5. (2006). Alderliesten,R.,Schijve,J.,andvander Zwaag,S.,“Application ofthe Energy Release Rate Approach for Delamination Growth in doi
  6. (1996). Analysis of Cracked Aluminum Plates Repaired with doi
  7. (2006). Challenges of the Metallic Fuselage,”
  8. Characterising Growth in Graphite-Epoxy,” Damage doi
  9. (1976). Compendium of Stress Intensity Factors, Her Majesty’s Stationery Office,
  10. (1988). Crack Patching: Experimental Studies, Practical Applications,” Bonded Repair of Aircraft Structures, doi
  11. (1990). Crack Stoppers and doi
  12. Crack Stoppers and Fail Safety
  13. (2005). Damage Tolerance and Fail Safety of Welded Aircraft Wing Panels,” doi
  14. (2003). Damage Tolerance Design and Analysis of doi
  15. Delamination Crack Growth doi
  16. (2003). Delamination Effects on Cracked Steel Members Reinforced by Prestressed doi
  17. Fail-Safe Design of Integral Metallic Aircraft Structures Reinforced by Bonded Crack Retarders,” Engineering Fracture Mechanics (to be published). doi
  18. (1987). Fibre Composite Repair of Cracked Metallic Aircraft Components–PracticalandBasicAspects,”Composites,Vol.18,No.4, doi
  19. Finite Element Analysis of Patched Cracks,”JournalofStructuralMechanics,Vol.7,No.2,1979,pp.107– doi
  20. (1995). Growth of Internal Delamination Under Cyclic Compression in Composite Plates,” doi
  21. (2005). Heinimann,M.B.,Bucci,R.J.,Kulak,M.,andGarratt,M.,“Improving Damage Tolerance of Aircraft Structures Through the Use of Selective Reinforcement,”
  22. (2007). Interaction of Interface Delamination and Plasticity in Tensile Steel Members Reinforced by doi
  23. Mechanics of Laminated Composite Plates and Shells: Theory and Analysis, doi
  24. (1996). Modelling of a Cracked Metallic Structure with Bonded Composite Patch Using doi
  25. (2006). Sabelkin,V.,Mall,S.,Avram,J.B.,“FatigueCrackGrowthAnalysisof Stiffened Cracked Panel Repaired with doi
  26. (2001). Software Tools for Analysis of Bonded Joints,” NASA/Goddard Space Flight Center TR-542,
  27. (2006). Strain Energy Release Rate Calculation forMovingDelaminationFrontofArbitraryShapeBasedontheVirtual Crack Closure Technique. Part 1: doi
  28. (2006). Strain Energy Release Rate Calculation forMovingDelaminationFrontofArbitraryShapeBasedontheVirtual Crack Closure Technique. Part 2: doi

To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.