Study on Damage Tolerance Behavior of Integrally Stiffened Panel and Conventional Stiffened Panel

The damage tolerance behavior of integrally and conventional stiffened panel is investigated based on the fracture mechanics and finite element analysis. The load bearing capability and crack growth characteristic of both types of the stiffened panels having same configuration subjected to distributed tensile load is examined in this paper. A fourteen-stringer stiffened panel is analyzed for a central skin crack propagating towards the adjacent stringers. Stress intensity factors and fatigue crack propagation rates of both types of the stiffened panels are then compared. The analysis results show that integral stiffening causes higher stress intensity factor than conventional stiffened panel as the crack tip passes through the stringer and the integrally stiffened panel has less load bearing capability than the riveted stiffened panel.

Authors:

• M. Adeel

Keywords:

• Conventional Stiffened Structure
• Damage Tolerance
• Finite Element Analysis
• Integrally Stiffened Structure
• Stress Intensity Factor.

References:

[1] R.G. Pettit, J. J. Wang, and C. Toh. Validated Feasibility Study of
Integrally Stiffened Metallic Fuselage Panels for Reducing
Manufacturing Costs, NASA/CR-2000-209342.
[2] B. R. Seshadri, J. C. Newman, Jr., D. S Dawicke and R. D. Young.
Fracture analysis of the FAA/NASA wide stiffened panels, NASA/TM-
1998-208976.
[3] Richard D. Young, Marshall Rouse, Damodar R. Ambur, and James H.
Starnes, Jr. Residual strength pressure tests and nonlinear analyses of
stringer- and frame-stiffened aluminum fuselage panels with longitudinal
cracks, NASA no. 19990021207, 1998.
[4] David Broek. Elementary Engineering Fracture Mechanics, Martinus
Nijhoff Publishers, 1982,pp.408-433.
[5] C. C. Poe. Crack Propagation in Stiffened Panels, ASTM STP 486,
1971.