Modal Properties of a Cantilevered Laminated Woven Composite Plate as Affected by Stacking Sequence and Fiber Orientation: An Experimental Study

2012 ◽  
Vol 225 ◽  
pp. 132-137 ◽  
Author(s):  
Dayang Laila Majid ◽  
Mohd Norhasani Abdullah Sani ◽  
Faizal Mustapha ◽  
Hafiz Hanafi ◽  
Mohamed Thariq Hameed Sultan
Keyword(s):  
Fiber Orientation ◽  
Composite Plate ◽  
Laminated Composite ◽  
Variable Stiffness ◽  
Modal Testing ◽  
Stacking Sequence ◽  
Structural Members ◽  
Modal Properties ◽  
Unidirectional Fibers ◽  
Woven Glass Fiber

The use of laminated composites in aircraft structures is not totally new. However, the idea of using woven fiber glass as reinforcement in primary structural members is not widely addressed as compared to unidirectional fibers. In an effort to characterize the dynamic behavior of a woven laminated composite subject to dynamic loads, modal testing is performed experimentally on a cantilevered laminated woven glass fiber/epoxy composite flat plate which resembles an aircraft wing with aspect ratio of 5. To that end, the effect of stacking sequence and fiber orientation of the laminated composite plate on the modal properties is assessed. 6-layer laminated composite configurations with various stacking sequence and fiber orientation are fabricated so as to generate variable stiffness plates. The modal test employs the single roving hammer technique to obtain the frequency response of the plate and the results of the first five modes against the fiber orientation and stacking sequence are analyzed.

scholarly journals Experimental and Numerical Buckling Analyses of Laminated Composite Plates under Temperature Effects

2010 ◽  
Vol 19 (4) ◽  
pp. 096369351001900 ◽  
Author(s):  
Emin Ergun
Keyword(s):  
Composite Plate ◽  
Numerical Solutions ◽  
Laminated Composite ◽  
Composite Plates ◽  
Buckling Load ◽  
Fibre Reinforcement ◽  
Stacking Sequence ◽  
Laminated Composite Plates ◽  
Different Temperatures ◽  
Good Agreement

The aim of this study is to investigate, experimentally and numerically, the change of critical buckling load in composite plates with different ply numbers, orientation angles, stacking sequences and boundary conditions as a function of temperature. Buckling specimens have been removed from the composite plate with glass-fibre reinforcement at [0°]i and [45°]i (i= number of ply). First, the mechanical properties of the composite material were determined at different temperatures, and after that, buckling experiments were done for those temperatures. Then, numerical solutions were obtained by modelling the specimens used in the experiment in the Ansys10 finite elements package software. The experimental and numerical results are in very good agreement with each other. It was found that the values of the buckling load at [0°] on the composite plates are higher than those of other angles. Besides, symmetrical and anti-symmetrical conditions were examined to see the effect of the stacking sequence on buckling and only numerical solutions were obtained. It is seen that the buckling load reaches the highest value when it is symmetrical in the cross-ply stacking sequence and it is anti-symmetrical in the angle-ply stacking sequence.

An analytical investigation of the best stacking sequence of a symmetric laminated composite plate weakened by a hole

2018 ◽  
Vol 24 (5) ◽  
pp. 1387-1404 ◽  
Author(s):  
Nirav P Patel ◽  
Dharmendra S Sharma
Keyword(s):  
Inverse Problem ◽  
Composite Plate ◽  
Fitness Function ◽  
Hybrid Genetic Algorithm ◽  
Laminated Composite ◽  
Stacking Sequence ◽  
Loading Conditions ◽  
Laminated Composite Plate ◽  
Variable Approach ◽  
Fiber Arrangement

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.

Finite element studies on buckling of laminated cylindrical skew panels

2014 ◽  
Vol 21 (4) ◽  
pp. 551-558 ◽  
Author(s):  
Chikkol Venkateshappa Srinivasa ◽  
Yalaburgi Jayadevappa Suresh ◽  
Wooday Puttiah Prema Kumar
Keyword(s):  
Finite Element ◽  
Fiber Orientation ◽  
Orientation Angle ◽  
Laminated Composite ◽  
Buckling Load ◽  
Stacking Sequence ◽  
Skew Angle ◽  
Buckling Loads ◽  
Critical Buckling Load ◽  
Fiber Orientation Angle

AbstractThe present paper presents the finite element studies made on critical buckling load of isotropic and laminated composite cylindrical skew panels. Analysis is performed using CQUAD4 and CQUAD8 elements of MSC/NASTRAN. It is found that the CQUAD8 element yields better results compared to the CQUAD4 element in terms of accuracy and convergence. Using the CQUAD8 element, the effects of the panel angle, skew angle, aspect ratio, and length-to-thickness ratio on the critical buckling load of isotropic cylindrical skew panels have been studied. The effects of additional parameters such as fiber orientation angle, numbers of layers (NL), and stacking sequence on the critical buckling load of laminated composite cylindrical skew panels have also been studied. The critical buckling loads are found to increase with the increase in panel angle and skew angle. When the NL in the laminate is large, the variation of the critical buckling load with the NL is not appreciable. The boundary conditions are found to have significant influence on the critical buckling load.

Hygrothermal Post-Buckling Analysis of Laminated Composite Beams

2019 ◽  
Vol 11 (01) ◽  
pp. 1950009 ◽  
Author(s):  
Şeref Doğuşcan Akbaş
Keyword(s):  
Fiber Orientation ◽  
Laminated Composite ◽  
Beam Theory ◽  
Nonlinear Problems ◽  
Composite Beams ◽  
Buckling Analysis ◽  
Stacking Sequence ◽  
Shear Beam ◽  
Post Buckling ◽  
Laminated Composite Beams

The main goal in this paper is to make analysis of post-buckling of laminated composite beams under hygrothermal effect. In solution of problem, finite element method is utilized with the first shear beam theory. Total Lagrangian approach is used nonlinear kinematic relations. It is known that post-buckling problems are geometrically nonlinear problems. In nonlinear solution of problem, the Newton–Raphson method is used based on incremental displacement. The novelty in this study is to investigate the hygrothermal post-buckling analysis of laminated composite beams by using total Lagrangian nonlinear approach. The influences of temperature, moisture, fiber orientation angles, stacking sequence of laminas on post-buckling responses of composite laminated beam are illustrated and examined in numerical results. The results show that fiber orientation angles, stacking sequence of laminas play an important role in hygrothermal post-buckling responses of laminated beams. Also, comparison studies are performed with special results of published paper.

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

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.

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

Polymers ◽  
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.

Sign in / Sign up

Export Citation Format

Share Document