Journal of Failure Analysis and Prevention

, Volume 12, Issue 2, pp 204–213 | Cite as

Optimization of Cut-Out Shape on Composite Plate Under In-Plane Shear Loading

  • V. Sivakumar
  • R. K. Arjun
  • V. Ishwarya
  • S. Nithya
  • Sreeja Sunder
  • B. N. Thilak
Technical Article---Peer-Reviewed

Abstract

The wing in flight condition is subjected to heavy aerodynamic loads that in turn lead to a shear flow over the wing ribs that support it. Cut-outs change the mechanical behavior of plates, as they redistribute the stresses and are influenced by the shape of the cut-out. A three-dimensional displacement-based finite element analysis is performed to study the symmetric, laminated composite plate of 20 layers. The analysis is performed to obtain the in-plane and out of plane performances of the laminate. Five basic cut-out geometries, viz., circle, square, diamond, ellipse with major axis along the y-axis, and another ellipse with major axis along the x axis were used for the numerical analysis. A cut-out geometry is generated based on the results of analyses performed on five basic geometries to optimize the performance. The optimized cut-out is associated with the least Tsai-Hill and Hashin failure index as compared with the five basic geometries.

Keywords

Cut-out Composite Optimization 

List of symbols

X (Xt or Xc)

Normal strength (tensile or compressive, respectively) of lamina in fiber direction-1

Y (Yt or Yc)

Normal strength (tensile or compressive, respectively) of lamina in direction transverse to the fiber direction-1

Z (Zt or Zc)

Normal strength (tensile or compressive, respectively) of lamina in principal material direction-3, i.e., perpendicular to plane of lamina

R, S, and T

Shear strengths of lamina in-planes 2–3, 1–3, and 1–2, respectively

σ1, σ2, and σ3

Normal stress components in principal material directions 1, 2, and 3, respectively (the subscript 1 referring to the fiber direction)

τ12, τ13, and τ23

Shear stress components in principal material planes 1–2, 1–3, and 2–3, respectively

E1, E2, and E3

Principal Young’s moduli in fiber direction and other two transverse directions, respectively

G12, G13, and G23

Shear moduli associated with planes 1–2, 1–3, and 2–3, respectively

ν12, ν13, and ν23

Poisson’s ratios associated with planes 1–2, 1–3, and 2–3, respectively

σDN

peel strength equal to the tensile normal transverse strength of lamina

σDS

Inter-laminar shear strength equal to transverse shear strength corresponding to the plane 1–3 of lamina

L

Lift force

X0

Distance of the section from the leading edge

Xac

Distance of the aerodynamic centre from the leading edge

M

Moment at any section from the leading edge

Mac

Moment about aerodynamic centre

C

Slope of the lift curve

Cmac

Coefficient of moment about aerodynamic centre

αmax

Maximum angle of attack

q

Dynamic pressure

q

Net shear flow

S

Planform area of wing

u, v, and w

Displacements in x, y, and z directions respectively

σx, σy, σz

Normal Stress in x, y, and z directions respectively

τxy, τxz, and τyz

Shear Stresses in planes xy, xz, and yz

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Copyright information

© ASM International 2012

Authors and Affiliations

  • V. Sivakumar
    • 1
  • R. K. Arjun
    • 1
  • V. Ishwarya
    • 1
  • S. Nithya
    • 1
  • Sreeja Sunder
    • 1
  • B. N. Thilak
    • 1
  1. 1.Department of Aerospace EngineeringAmrita School of Engineering, Amrita Vishwa Vidyapeetham (University)CoimbatoreIndia

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