عنوان مقاله [English]
نویسندگان [English]چکیده [English]
Thin reinforced plates are utilized widely in many fields of engineering industries. Existence of crack is an important factor of failure in such structures, which can lead to structural damage in less time than its real function without the crack. In this paper, stress intensity factors for mode one and mode two of fracture are studied in isogrid thin plate reinforced with diamond lattice and stiffeners with T-shaped cross section under uniaxial and biaxial loading conditions to find the difference with simple plates. The rectangular reinforced plate has 12 stiffener ribs with angle of 60 degrees regarding to transverse axis. In order to model the reinforced sheet, plates and stiffeners are assembled together uniformly. Modeling and analysis are performed using Abaqus finite element software; and the effect of various parameters such as length and angle of the crack and also, the different loading conditions on stress intensity factors in reinforced lattice plane are investigated. The results show that each of the investigated variables has a significant impact on stress intensity factors. Also, by changing the angle of crack or at different loading conditions, the stress intensity factors can have negative values in lattice reinforced thin plate.
 E. Byskov, The calculation of stress intensity factors using the finite element method withE cracked elements, International Journal of Fracture Mechanics, Vol. 6, No. 2, pp. 159-167, 1970.
 D. M. Tracey, Finite elements for determination of crack tip elastic stress intensity factors, Engineering Fracture Mechanics, Vol. 3, No. 3, pp. 255-265, 1971.
 D. F. Mowbray, A note on the finite element method in linear fracture mechanics, Engineering Fracture Mechanics, Vol. 2, No. 2, pp. 173-176, 1970.
 C.C. Poe J.R., The effect of broken stringers on the stress intensity factor for a uniformly stiffened sheet containing a crack, Proceedings of The 10th Anniv. Meeting of The Soc. of Eng. Sci., Raleigh, US, Nov. 5-7, 1973.
 M. Isida, Analysis of stress intensity factors for the tension of a centrally cracked strip with stiffened edges, Engineering Fracture Mechanics, Vol. 5, No. 3, pp. 647-665, 1973.
 P. D. Hilton, Plastic intensity factors for cracked plates subjected to biaxial loading, International Journal of Fracture, Vol. 9, No. 2, pp. 149-156, 1973.
 M. M. Ratwani, D. P. Wilhem, Influence of biaxial loading on analysis of cracked stiffened panels, Engineering Fracture Mechanics, Vol. 11, No. 3, pp. 585-593, 1979.
 T. P. Rich, M. M. Ghassem, D. J. Cartwright, Fracture diagrams for cracked stiffened panels, Engineering Fracture Mechanics, Vol. 21, No. 5, 1005-1017, 1985.
 S. V. Shkarayev, E. T. Mover, Edge cracks in stiffened plates, Engineering Fracture Mechanics, Vol. 27, No. 2, pp. 127-134, 1987.
 Y. J. Yum, C. S. Hong, Stress intensity factors in finite orthotropic plates with a crack under mixed mode deformation, International Journal of Fracture, Vol. 47, No. 1, pp. 53-67, 1991.
 J. R. Yeh, Fracture analysis of a stiffened orthotropic sheet, Engineering Fracture Mechanics, Vol. 46, No. 5, pp. 857-866, 1993.
 N. K. Salgado, M. H. Aliabadi, The application of the dual boundary element method to the analysis of cracked stiffened panels, Engineering Fracture Mechanics, Vol. 54, No. 1, pp. 91-105, 1996.
 A. Vafai, H. E. Estekanchi, A parametric finite element study of cracked plates and shells, Thin-Walled Structures, Vol. 33, No. 3, pp. 211-229, 1999.
 A. Vafai, M. Javidruzi, H. E. Estekanchi, Parametric instability of edge cracked plates, Thin-walled structures, Vol. 40, No. 1, pp. 29-44, 2002.
 B. N. Rao, S. Rahman, A coupled meshless-finite element method for fracture analysis of cracks, International Journal of Pressure Vessels and Piping, Vol. 78, No. 9, pp. 647-657, 2001.
 K.Y.V. Satish, J. K. Paik, Buckling analysis of cracked plates using hierarchical trigonometric functions, Thin-Walled Structures, Vol. 42, No. 5, pp. 687-700, 2004.
 R. Brighenti, Buckling of cracked thin-plates under tension or compression, Thin-Walled Structures, Vol. 43, No. 2, pp. 209-224, 2005.
 N. A. Fleck, X. M. Qiu, The damage tolerance of elastic–brittle, two-dimensional isotropic lattices, Journal of the Mechanics and Physics of Solids, Vol. 55, No. 3, pp. 562-588, 2007.
 M. Fossati, D. Colombo, A. Manes, M. Giglio, Numerical modelling of crack growth profiles in integral skin-stringer panels, Engineering Fracture Mechanics, Vol. 78, No. 7, pp. 1341-1352, 2011.
 A. Abdollahifar, M. R. Nami, Investigating the effect of angle between the material gradation direction and crack on mixed-mode stress intensity factor of FGM plates using MLPG method, Modares Mechanical Engineering, Vol. 13, No. 1, pp. 138-150, 2012. (in Persianفارسی )
 Y. Margaritis, M. Toulios, The ultimate and collapse response of cracked stiffened plates subjected to uniaxial compression, Thin-Walled Structures, Vol. 50, No. 1, pp. 157-173, 2012.
 C. Rans, R. Rodi, R. Alderliesten, Analytical prediction of Mode I stress intensity factors for cracked panels containing bonded stiffeners, Engineering Fracture Mechanics, Vol. 97, pp. 12-29, 2013.
 A. Bayatfar, M. R. Khedmati, P. Rigo, Residual ultimate strength of cracked steel unstiffened and stiffened plates under longitudinal compression, Thin-Walled Structures, Vol. 84. pp. 378-392, 2014.
 M. C. Xu, Y. Garbatov, C. Guedes Soares, Residual ultimate strength assessment of stiffened panels with locked cracks, Thin-Walled Structures, Vol. 85, pp. 398-410, 2014.
 A. Ghasemi Ghalebahman, S. Salavati, Utilizing the extended finite element method for determining crack stress intensity factors and higher order terms coefficients, Modares Mechanical Engineering, Vol. 15, No. 2, pp.135-146, 2015. (in Persianفارسی )
 F. Erdogan, G. C. Sih, On the crack extension in plates under plane loading and transverse shear, Journal of Basic Engineering, Vol. 85, No. 4, pp. 519-525, 1963.
 M. A. Hussain, S. L. Pu, J. Underwood, Strain energy release rate for a crack under combined mode I and mode II, In Fracture Analysis: Proceedings of The 1973 National Symposium on Fracture Mechanics, Part II. ASTM International, 1974.
 G. C. Sih, Some basic problems in fracture mechanics and new concepts, Engineering Fracture Mechanics, Vol. 5, No. 2, pp. 365-377, 1973.
 J. Eftis, Load biaxiality and fracture: a two-sided history of complementing errors, Engineering Fracture Mechanics, Vol. 26, No. 4, pp. 567-592, 1987.
 Military Handbook, Metalic Materials and Elements for Aerospace Vehicle Structures, MIL-HDBK-5H, U.S. Department of Defense, Dec. 1998.