BUCKLING OF LAMINATED COMPOSITE PLATE UNDER BIAXIAL LOADING CONDITIONS

The investigation of the best set of fiber arrangements of a composite laminated structure under various loading conditions is very challenging and the analytical derivation is also complex when the laminate contains various shaped discontinuities. In this article, the best stacking sequence is investigated by treating it as an inverse problem, in which the best fiber arrangement is predicted considering maximization of the failure strength as an objective function. This inverse problem is solved using the hybrid genetic algorithm that operates the Tsai–Hill quadratic criterion as a fitness function and stacking sequence as design variables. A 4, 8 and 16-layered symmetrical laminated composite plate containing a triangular and square hole is optimized by considering the in-plane loading conditions, and the stresses in the Tsai–Hill quadratic criterion are calculated by an analytical solution of Muskhelishvili’s complex variable approach. The problem of the calculation of stresses and failure strengths from the estimated fiber arrangement data is presented as a forward problem. The effect of hole geometry and loading angle on an optimum design is also presented. The presented approach will be useful as an effective tool to study composites.

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Stress analysis of infinite laminated composite plate with elliptical cutout under different in plane loadings in hygrothermal environment

Curved and Layered Structures ◽

10.1515/cls-2021-0001 ◽

2021 ◽

Vol 8 (1) ◽

pp. 1-12

Author(s):

Ashok Magar ◽

Achchhe Lal

Keyword(s):

Stress Concentration ◽

Stress Distribution ◽

Composite Plate ◽

Volume Fraction ◽

Elliptical Hole ◽

Laminated Composite ◽

Laminated Composite Plate ◽

Concentration Changes ◽

Hygrothermal Environment ◽

Plate Analysis

Abstract This paper presents the solution of stress distribution around elliptical cutout in an infinite laminated composite plate. Analysis is done for in plane loading under hygrothermal environment. The formulation to obtain stresses around elliptical hole is based on Muskhelishvili’s complex variable method. The effect of fibre angle, type of in plane loading, volume fraction of fibre, change in temperature, fibre materials, stacking sequence and environmental conditions on stress distribution around elliptical hole is presented. The study revealed, these factors have significant effect on stress concentration in hygrothermal environment and stress concentration changes are significant with change in temperature.

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Moments around elliptical hole in a symmetric laminated composite plate under hygrothermal environment

Materials Today Proceedings ◽

10.1016/j.matpr.2020.10.448 ◽

2020 ◽

Author(s):

Ashok Magar ◽

Achchhe Lal

Keyword(s):

Composite Plate ◽

Elliptical Hole ◽

Laminated Composite ◽

Laminated Composite Plate ◽

Hygrothermal Environment

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Experimental and Numerical Analyses on the Buckling Characteristics of Woven Flax/Epoxy Laminated Composite Plate under Axial Compression

Polymers ◽

10.3390/polym13070995 ◽

2021 ◽

Vol 13 (7) ◽

pp. 995

Author(s):

Venkatachalam Gopalan ◽

Vimalanand Suthenthiraveerappa ◽

Jefferson Stanley David ◽

Jeyanthi Subramanian ◽

A. Raja Annamalai ◽

...

Keyword(s):

Environmental Sustainability ◽

Composite Plate ◽

Compressive Load ◽

Laminated Composite ◽

Green Composite ◽

Laminated Composite Plate ◽

Axial Compressive Load ◽

Number Of Layers ◽

Structural Applications ◽

Ply Orientation

The evolution of a sustainable green composite in various loadbearing structural applications tends to reduce pollution, which in turn enhances environmental sustainability. This work is an attempt to promote a sustainable green composite in buckling loadbearing structural applications. In order to use the green composite in various structural applications, the knowledge on its structural stability is a must. As the structural instability leads to the buckling of the composite structure when it is under an axial compressive load, the work on its buckling characteristics is important. In this work, the buckling characteristics of a woven flax/bio epoxy (WFBE) laminated composite plate are investigated experimentally and numerically when subjected to an axial compressive load. In order to accomplish the optimization study on the buckling characteristics of the composite plate among various structural criterions such as number of layers, the width of the plate and the ply orientation, the optimization tool “response surface methodology” (RSM) is used in this work. The validation of the developed finite element model in Analysis System (ANSYS) version 16 is carried out by comparing the critical buckling loads obtained from the experimental test and numerical simulation for three out of twenty samples. A comparison is then made between the numerical results obtained through ANSYS16 and the results generated using the regression equation. It is concluded that the buckling strength of the composite escalates with the number of layers, the change in width and the ply orientation. It is also noted that the weaving model of the fabric powers the buckling behavior of the composite. This work explores the feasibility of the use of the developed green composite in various buckling loadbearing structural applications. Due to the compromised buckling characteristics of the green composite with the synthetic composite, it has the capability of replacing many synthetic composites, which in turn enhances the sustainability of the environment.

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