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An Optimum Stringer for Straight and Curved Stiffened Panels Using X-FEM Techniques

Krishna Lok Singh, Rajesh Reddy


In this study, crack growth, modeling and simulation of various stiffened stringers, unstiffened straight and curved cracked panels are presented using commercially available finite element software package. Computation of stresses and convergence of stress intensity factor for single-edge notch specimens computed using finite element method (FEM) and extended finite element method (X-FEM) and compared with analytical solution. X-FEM techniques like cohesive segment method and linear elastic fracture mechanics, using virtual crack closure technique, are used for crack growth simulation and presented results for unstiffened, stiffened and curved panels. The nonlinear analysis considering both geometric and material nonlinearity on both straight and curved panels stiffened with various stringers like straight, inverted L, T, and Z sections performed analyses. Quantified the maximum load-carrying capacity in each of the panels like unstiffened and stiffened in both the configurations of straight and curved panels. Arrived at the optimum stringer section type for the considered panel under axial loading from the numerical analysis.


cohesive segment method; crack growth; SIF; VCCT; various stringers; X-FEM

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