Experimental and Finite Element Studies on Buckling of Laminated E-Glass Woven Fabric Epoxy Composite Plates Mr. Ramesh N R M.Tech. Student, Reva Institute of Technology and Management, Bangalore Mr. Thyagaraj N R Assistant Professor, Department of Mechanical Engineering, SJCIT, Chickaballapur Dr. Prema Kumar W P Senior Professor, Department of Civil Engineering, Reva Institute of Technology and Management, Bangalore Dr. Prathap Kumar M T Senior Professor, Department of Civil Engineering, Reva Institute of Technology and Management, Bangalore Abstract— The laminated composite structures have wide application in aerospace, mechanical, civil and other areas of engineering chiefly due to the low value of specific weight and high values of specific strength and specific stiffness. The thickness of members and structures made of composite materials is usually very small and hence prone to buckling. Buckling behavior of laminated composite plates subjected to in- plane loads is an important consideration in the preliminary design of automobile components. Composite plates with circular holes and other openings are extensively used as structural members in automobile design and other fields. In this work, experimental and finite element studies are made on buckling of rectangular plates made of laminated E-glass woven fabric epoxy composite plates with and without cutouts. The effects of (i) fabric orientation angle and (ii) shape of cutout (circular, square and rectangular) on the critical buckling load are determined. It is observed that for all composite plates considered here, the value of critical buckling stress given by FEM (finite element method) is higher than the corresponding experimental value, the discrepancy varying from small to moderate. The critical buckling stresses given by both experimental and finite element methods decrease monotonically as the fabric orientation angle increases. The values are maximum for 0 0 fabric orientation and minimum for 45 0 fabric orientation. The values of the critical buckling load given by buckling experiment and FEM reduce when cutouts/holes are introduced in the composite plates. The reduction in the value of critical buckling load is considerable. The shape of the hole does influence, although not significantly, the critical buckling load when the areas of the holes are almost same. The plate with circular hole yields higher value when compared with a plate with square/rectangular hole. Keywords— laminated composite plate; woven fabric; fabric orientation; cutout; critical buckling load; finite element analysis I. INTRODUCTION Fiber-reinforced and fabric reinforced composites are used extensively in the form of thin plates which are prone to buckling. Hence an understanding and evaluation of their buckling behavior is vital in the safe and reliable design of laminated composite plates. There are several analytical and numerical studies made on thin laminated composite plates and a few of them are briefly mentioned here. Shukla and Kreuzer [1] proposed a formulation based on the first-order shear deformation theory and von-Karman- type nonlinearity to estimate the critical buckling load of laminated composite rectangular plates under in-plane uniaxial and biaxial loadings. Different combinations of simply supported, clamped and free boundary conditions were considered. The effects of plate aspect ratio, lamination scheme, number of layers and material properties on the critical loads were studied. Chainarin Pannok et al. [2] studied the buckling behavior of rectangular and skew thin composite plates with various boundary conditions using the Ritz method along with the proposed out-of-plane displacement functions. Buket Okutan Baba [3] conducted numerical and experimental studies and investigated the effect of boundary conditions, length/thickness ratio and ply orientation on the buckling behavior of E-glass/epoxy composite rectangular plates with and without cutouts under in-plane compression load. Pein and Zahari [4] studied the structural behavior of woven fabric composites with and without holes subject to compressive load. Murat Yazici [5] studied the influence of square cut-out on the buckling stability of multilayered, steel woven fiber-reinforced polypropylene thermoplastic matrix composite plates using numerical and experimental methods. Ganesan C and P K Dash [6] studied the effect of holes in plate elements on the stability. This study dealt with the buckling analysis of symmetrically laminated composite plates with two sides simply supported and the remaining two sides free. Priyanka International Journal of Engineering Research & Technology (IJERT) ISSN: 2278-0181 www.ijert.org Vol. 3 Issue 7, July - 2014 IJERTV3IS070446 303