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        1 - Determination of the Effective Parameters for Perforated Functionally Graded Plates with Polygonal Cutout by Analytical Solution
        M Jafari M. H Bayati Chaleshtari H Abdolalian
        This paper investigates the moments and stress resultants from infinite FG laminates with different polygonal cutouts subject to uniaxial tensile load. The analytical solution used for the calculation of stress resultants and moments is the basis of the complex-variable أکثر
        This paper investigates the moments and stress resultants from infinite FG laminates with different polygonal cutouts subject to uniaxial tensile load. The analytical solution used for the calculation of stress resultants and moments is the basis of the complex-variable method and conformal mapping function. The impact of various factors, namely cutout orientation angle, cutout aspect ratio as well as the cutout corner curve on stress distribution and moment resultants is studied. The effect of the aforementioned parameters around triangular, square, pentagonal and hexagonal cutout is analyzed. The mechanical characteristics of the graded plates are hypothesized to vary throughout the thickness exponentially. Finite element numerical solution is employed to examine the results of the present analytical solution. This comparison showed a favorable agreement level among the acquired analytical and numerical outcomes. تفاصيل المقالة
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        2 - Analytical Study on the Effect of Stacking Sequence on the Maximum Allowable Heat Flux in Perforated Symmetric Composite Laminates Subjected to Uniform Heat Flux
        M.H Bayati Chaleshtari H Khoramishad M Jafari
        An analytical solution was used for obtaining the maximum allowable heat flux in symmetric composite laminates containing a quasi-square cutout with different stacking sequences subjected to uniform heat flux. The Tsai-Hill criterion was used to assess the maximum allow أکثر
        An analytical solution was used for obtaining the maximum allowable heat flux in symmetric composite laminates containing a quasi-square cutout with different stacking sequences subjected to uniform heat flux. The Tsai-Hill criterion was used to assess the maximum allowable heat flux of the laminate. The analytical solution was obtained based on the thermoelasticity theory and the Lekhnitskii’s method. Furthermore, by employing a suitable mapping function, the solution of symmetric laminates with a circular cutout was extended to the quasi-square cutout. The quasi-square cutout was studied in a symmetric laminate made of Glass/epoxy with different stacking sequences of [0/90]S, [45/-45]S , [30/-30]S. The results showed that the maximum allowable heat flux experienced in perforated plates can be improved by considering the appropriate stacking sequence and the optimal values of the cutout parameters. According to the results, the best cutout geometry was not always a circle, as in some cases by choosing the appropriate values of bluntness parameter, cutout orientation, heat flux angle, cutout aspect ratio and laminate stacking sequence, a non-circular cutout provided higher maximum allowable heat flux value for a perforated plate than a circular cutout. تفاصيل المقالة
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        3 - Free Vibration Analysis of Moderately Thick Functionally Graded Plates with Multiple Circular and Square Cutouts Using Finite Element Method
        J Vimal R.K Srivastava A.D Bhatt A.K Sharma
        A simple formulation for studying the free vibration of shear-deformable functionally graded plates of different shapes with different cutouts using the finite element method is presented. The aim is to fill the void in the available literature with respect to the free أکثر
        A simple formulation for studying the free vibration of shear-deformable functionally graded plates of different shapes with different cutouts using the finite element method is presented. The aim is to fill the void in the available literature with respect to the free vibration results of functionally graded plates of different shapes with different cutouts. The material properties of the plates are assumed to vary according to a power law distribution in terms of the volume fraction of the constituents. Validation of the formulation is done with the help of convergence studies with respect to the number of nodes and the results are compared with those from past investigations available only for simpler problems. In this paper rectangular, trapezoidal and circular plates with cutouts are studied and the effects of volume fraction index, thickness ratio and different external boundary conditions on the natural frequencies of plates are studied. تفاصيل المقالة
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        4 - Numerical and Experimental Study of Buckling of Rectangular Steel Plates with a Cutout
        M Shariati Y Faradjian H Mehrabi
        Steel plates are used in various structures, such as the structures of the deck and body of ships, bridges, and aerospace industry. In this study, we investigate the buckling and post-buckling behavior of rectangular steel plates having circular cutouts with two boundar أکثر
        Steel plates are used in various structures, such as the structures of the deck and body of ships, bridges, and aerospace industry. In this study, we investigate the buckling and post-buckling behavior of rectangular steel plates having circular cutouts with two boundary conditions: first, clamped supports at upper and lower ends and free supports at other edges; second, clamped supports at upper and lower ends and simply supports at other edges, using finite element method (by ABAQUS software) and experimental tests(by an INSTRON servo hydraulic machine). In this research, in addition to the aspect ratio, the effect of changing the location of the cutout on the buckling analysis is investigated. The results of both numerical and experimental analyses are compared and showing a very good agreement between them. تفاصيل المقالة
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        5 - Numerical and Experimental Study on Ratcheting Behavior of Steel Cylindrical Shells with/without Cutout Under Cyclic Combined and Axial Loading
        M Shariati K Kolasangiani H.R Epakchi H Chavoshan
        Ratcheting behavior of steel 304L cylindrical shell under cyclic combined and axial loading are investigated in this paper, numerically. Cylindrical shells were fixed oblique at angle of 20° and normal with respect to the longitudinal direction of the shell and subj أکثر
        Ratcheting behavior of steel 304L cylindrical shell under cyclic combined and axial loading are investigated in this paper, numerically. Cylindrical shells were fixed oblique at angle of 20° and normal with respect to the longitudinal direction of the shell and subjected to force-controlled cycling with non-zero mean force, which causes the accumulation of plastic deformation or ratcheting behavior. Numerical analysis was carried out by ABAQUS software using nonlinear isotropic/kinematic hardening model. Numerical results compared to experimental data that was performed by an INSTRON 8802 servo hydraulic machine. Simulations show good agreement between numerical and experimental results. Also, the effect of length, angle of cylindrical shell and existence of cutout are studied with finite element method. Seen, the bending moment plays a strong role in increase of plastic deformation. It is observed that there is more plastic deformation for cylindrical shell under combined loading in comparison to cylindrical shell under uniaxial loading. Ratcheting behavior is sensitive to cutout and showed that creating the cutout increases the plastic deformation. تفاصيل المقالة
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        6 - Free Vibration of Functionally Graded Cylindrical Shell Panel With and Without a Cutout
        k.S Sai Ram K Pratyusha P Kiranmayi
        The free vibration analysis of the functionally graded cylindrical shell panels with and without cutout is carried out using the finite element method based on a higher-order shear deformation theory. A higher-order theory is used to properly account for transverse shea أکثر
        The free vibration analysis of the functionally graded cylindrical shell panels with and without cutout is carried out using the finite element method based on a higher-order shear deformation theory. A higher-order theory is used to properly account for transverse shear deformation. An eight noded degenerated isoparametric shell element with nine degrees of freedom at each node is considered. The stiffness and mass matrices are derived based on the principle of minimum potential energy. The stiffness and mass matrices of the element are evaluated by performing numerical integration using the Gaussian quadrature. The effect of volume fraction exponent on the fundamental natural frequency of simply supported and clamped functionally graded cylindrical shell panel without a cutout is studied for various aspect ratios and arc-length to thickness ratios. Results are presented for variation of the fundamental natural frequency of the cylindrical shell panel with cutout size for simply supported and clamped boundary conditions. تفاصيل المقالة
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        7 - Numerical and Experimental Study on Ratcheting Behavior of Plates with Circular Cutouts under Cyclic Axial Loading
        K Kolasangiani M Shariati Kh Farhangdoost A Varvani-Farahani
        In this paper, accumulation of plastic deformation of AISI 1045 steel plates with circular cutouts under cyclic axial loading is studied. Loading was applied under force-control conditions. Experimental tests were performed using a Zwick/Roell servo hydraulic machine. U أکثر
        In this paper, accumulation of plastic deformation of AISI 1045 steel plates with circular cutouts under cyclic axial loading is studied. Loading was applied under force-control conditions. Experimental tests were performed using a Zwick/Roell servo hydraulic machine. Under force-control loading with nonzero mean force, plastic strain was accumulated in continuous cycles called ratcheting. Numerical analysis was carried out by ABAQUS software using nonlinear isotropic/kinematic hardening model. The results of the numerical simulations were compared to experimental data. The results demonstrated that the ratcheting response of plates with circular cutouts could be numerically simulated with a reasonable accuracy. It was observed that the local and global plastic deformation increase with increasing the notch diameter. Also, maximum principal stress was the main parameter for initiation of crack around the notch. Based on numerical results, at notch root, both ratcheting strain and local mean stress relaxation was occur simultaneously and due to relaxation of local mean stress, plastic shakedown was occurred. تفاصيل المقالة
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        8 - Investigation of Pre-buckling Stress Effect on Buckling Load Determination of Finite Rectangular Plates with Circular Cutout
        S Abolghasemi H.R Eipakchi M Shariati
        This paper investigates the buckling of finite isotropic rectangular plates with circular cutout under uniaxial and biaxial loading. The complex potential method is used to calculate the pre-buckling stress distribution around the cutout in the plate with finite dimensi أکثر
        This paper investigates the buckling of finite isotropic rectangular plates with circular cutout under uniaxial and biaxial loading. The complex potential method is used to calculate the pre-buckling stress distribution around the cutout in the plate with finite dimensions. To satisfy the in-plane boundary conditions, the generalized complex-potential functions are introduced and a new method based on the boundary integral which has been obtained from the principle of virtual work is used to apply the boundary conditions at the plate edges. The potential energy of the plate is calculated by considering the first order shear deformation theory and the Ritz method is used to calculate the buckling load. The effects of cutout size, type of loading and different boundary conditions on the buckling load are investigated. Comparing of the calculated buckling loads with the finite element results shows the accuracy of the presented method for buckling analysis of the plates. تفاصيل المقالة