Buckling Load Maximization of Curvilinearly Stiffened Tow-Steered Laminates

The stacking sequence of composite laminates is designed to have maximum buckling load using the particle swarm optimization (PSO) algorithm. The original PSO algorithm is modified to handle the discrete ply angles and the constraints such as stiffness and 4-ply contiguity requirements. For this, the augmented Lagrange multiplier (ALM) method is incorporated into the PSO algorithm. For the verification of the algorithm, the benchmarking problems are solved and the results are compared with the ones from the genetic algorithm or the analytic solutions. And then the laminates under in-plane compressive loadings are optimized for maximum buckling load considering the various constraints. The numerical results show that the algorithm finds the optimum with relatively small number of iterations with satisfying the constraints explicitly. Considering its advantage of derivative-free and simple procedures, the proposed algorithm can be applied to more complex models coupled with finite element analysis and various constraints.

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Design of Variable Stiffness Cylinder with Holes Under Bending for Maximum Buckling Load Using Lamination Parameters

10.33599/nasampe/s.19.1378 ◽

2019 ◽

Author(s):

Mazen Albazzan ◽

Brian Tatting ◽

Ramy Harik ◽

Zafer Gürdal ◽

Adriana Blom-Schieber ◽

...

Keyword(s):

Variable Stiffness ◽

Buckling Load ◽

Lamination Parameters

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Identification approach to estimate buckling load of damaged composite plates

AIAA Journal ◽

10.2514/3.13992 ◽

1998 ◽

Vol 36 ◽

pp. 1479-1485

Author(s):

Anil L. Salunkhe ◽

Prasanna M. Mujumdar

Keyword(s):

Composite Plates ◽

Buckling Load ◽

Identification Approach

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Hydraulic fluid power. Cylinders. Method for determining the buckling load

10.3403/02362594 ◽

2001 ◽

Keyword(s):

Buckling Load ◽

Fluid Power ◽

Hydraulic Fluid

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Flexural-Torsional Buckling of Pultruded Fiber-Reinforced Polymer Angle Beams under Eccentric Loading

Materials Science Forum ◽

10.4028/www.scientific.net/msf.982.201 ◽

2020 ◽

Vol 982 ◽

pp. 201-206

Author(s):

Jaksada Thumrongvut ◽

Natthawat Pakwan ◽

Samaporn Krathumklang

Keyword(s):

Buckling Load ◽

Fiber Reinforced Polymer ◽

Width Ratio ◽

Fiber Reinforced ◽

Torsional Buckling ◽

Eccentric Load ◽

Buckling Loads ◽

Reinforced Polymer ◽

Cross Sectional Dimension ◽

Flexural Torsional Buckling

In this paper, the experimental study on the pultruded fiber-reinforced polymer (pultruded FRP) angle beams subjected to transversely eccentric load are presented. A summary of critical buckling load and buckling behavior for full-scale flexure tests with various span-to-width ratios (L/b) and eccentricities are investigated, and typical failure mode are identified. Three-point flexure tests of 50 pultruded FRP angle beams are performed. The E-glass fibre/polyester resin angle specimens are tested to examine the effect of span-to-width ratio of the beams on the buckling responses and critical buckling loads. The angle specimens have the cross-sectional dimension of 76x6.4 mm with span-to-width ratios, ranging from 20 to 40. Also, four different eccentricities are investigated, ranging from 0 to ±2e. Eccentric loads are applied below the horizontal flange in increments until beam buckling occurred. Based upon the results of this study, it is found that the load and mid-span vertical deflection relationships of the angle beams are linear up to the failure. In contrast, the load and mid-span lateral deflection relationships are geometrically nonlinear. The general mode of failure is the flexural-torsional buckling. The eccentrically loaded specimens are failed at critical buckling loads lower than their concentric counterparts. Also, the quantity of eccentricity increases as buckling load decreases. In addition, it is noticed that span-to-width ratio increases, the buckling load is decreased. The eccentric location proved to have considerable influence over the buckling load of the pultruded FRP angle beams.

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