Ayob Amran

Optimization of Temperature-Dependent Functionally Graded Material Based on Colonial Competitive Algorithm

A functionally graded material is optimized for thermal buckling. The buckling problem is formulated where temperature-dependence constituents’ properties are included. Then the Colonial Competitive Algorithm (CCA) is used for optimization of critical thermal buckling load with variation thickness. The results CCA optimization is compared with third order shear deformation theory and another optimum method based on Genetic Algorithm (GA).

Effect of Strain-Rate on Flexural Behavior of Composite Sandwich Panel

In the past few decades, Composite Sandwich Panel (CSP) technology significantly influenced the design and manufacturing of high performance structures. Although using CSP increases the reliability of structure, the important concern is to understand the complex deformation and damage evolution process. This study is focused on the mechanical behaviour of CSP under flexural loading condition. A setup of three-point bending test is prepared using three support span of 40, 60 and 80 mm. The loading was controlled by three different displacement rates of 1, 10 and 100 mm per minute to examine the effects of strain-rate on bending behaviour of CSP material. The beam span significantly affects the flexural stiffness of CSP panel. The load-deflection response of the panel shows two different portions, that representing equivalent elastic and plastic regions in both the core and facesheets components of CSP. The non-combustible mineral-filled core appears to be nonlinear in the elastic region, at high loading rate. Consequently the failure occurs as the core/facesheets interface suffers debonding.

Experimental Investigation on Free Vibration of Foam-Core Sandwich Plate with and without Circular Polymer Columns

Free vibration modes of foam-core sandwich plates with and without polymer columns were experimentally identified from frequency response tests. The responses were made at selected locations on the plate surface by attaching a single-axis accelerometer to measure out-of-plane response. Resonant frequencies, relative damping ratios and mode shapes were established for the lowest 3 out-of-plane modes found in the frequency range of 0-900 Hz. The results show that the vibration characteristics were affected by the sandwich structure configuration and material properties.

Imperialist competitive algorithm for multiobjective optimization of ellipsoidal head of pressure vessel

This work devoted to an ellipsoidal head of pressure vessel under internal pressure load. The analysis is aimed at finding an optimum weight of ellipsoidal head of pressure vessel due to maximum working pressure that ensures its full charge with stresses by using imperialist competitive algorithm and genetic algorithm. In head of pressure vessel the region of its joint with the cylindrical shell is loaded with shear force and bending moments. The load causes high bending stresses in the region of the joint. Therefore, imperialist competitive algorithm was used here to find the optimum shape of a head with minimum weight and maximum working pressure which the shear force and the bending moment moved toward zero. Two different size ellipsoidal head examples are selected and studied. The imperialist competitive algorithm results are compared with the genetic algorithm results.

Buckling behavior of optimal laminated composite cylindrical shells subjected to axial compression and external pressure

In this study, the buckling behavior of optimum laminated composite cylindrical shells subjected to axial compression and external pressure are studied. The cylindrical shells are composed of multi orthotropic layers that the principal axis gets along with the shell axis (x). The number of layers and the fiber orientation of layers are selected as optimization design variables with the aim to find the optimal laminated composite cylindrical shells. The optimization procedure was formulated with the objective of finding the highest buckling pressure. The Genetic Algorithm (GA) and Imperialist Competitive Algorithm (ICA) are two optimization algorithms that are used in this optimization procedure and the results were compared. Also, the effect of materials properties on buckling behavior was analyzed and studied.

Effect of Manufacturing Process on Free Vibration of Foam-Core Sandwich Plate

In this paper, the effect of the manufacturing process on free vibration modes of foam-core sandwich plate were experimentally identified from frequency response tests. Three types of foam-core sandwich plate that fabricated by using hand lay-up, vacuum bagging and vacuum infusion process were tested and compared. The responses were made at selected locations on the plate surface by attaching a single-axis accelerometer to measure out-of-plane response. Resonant frequencies, relative damping ratios and mode shapes were established for the lowest 3 out-of-plane modes found in the frequency range of 0-900 Hz. The results show that the vibration characteristics were affected by the fabrication process of the sandwich structure.

Quasi-Static Flexural and Tensile Behavior of Glass Fiber Reinforced Polymer

In this paper, glass fiber reinforce polymer subject to quasi-static three point bending loading and tensile loading was studied experimentally. Glass fiber reinforced made of chopped strand mat (CSM) were used in this study. Several samples were prepared and tested by using Instron universal testing machine at different strain rate including 1mm/min, 10mm/min and 100mm/min and all of the tests were repeated three times in order to minimize experimental error and the average of the obtained results were used for further analysis. The load-extension curves and stress-strain curve of glass fiber reinforce subject to three point bending and tensile loading test were determined at different strain rate and the obtained results were compared together. As results of this study, it has found that the strain rate has effect on flexural and tensile behavior of glass fiber reinforce.

Multi-Objective Optimization of Filament Wound Composite Pressure Vessels Based on Weight and Matrix Cracking/ Burst Pressure Using Imperialist Competitive Algorithm

The most important concern in design of filament-wound composite pressure vessels reflects on the determination of the optimum shape and optimum laminate stacking sequence of composite vessels based on the matrix cracking pressure and burst pressure of composite laminates. In this study the Imperialist Competitive Algorithm (ICA) is used to find the optimum laminate stacking sequence of composite vessels that the design considerations are stability and strength constraints. the matrix cracking pressure of filament-wound composite pressure vessels made of different number of helical layers and different layers of Circumferential layers was calculated by using orthotropic material formulae and then, the burst pressure of composite vessels was calculated by using netting analysis. The optimum laminate stacking sequence of filament winding composite was found to maximize the matrix cracking pressure and the burst pressure by using Imperialist Competitive algorithm.

Optimum size of a ground-based cylindrical liquid storage tank under stability and strength constraints using Imperialist Competitive Algorithm

Steel cylindrical tank is one of the most common forms of liquid storage vessels. In this study the Imperialist Competitive Algorithm (ICA) is used to find the optimum size of a ground based cylindrical liquid storage tank that is supported at both ends and the design considerations are stability and strength constraints. In this study total internal pressure and total special pressure are assumed as two types of load. The optimization procedure is formulated with the objective to minimize the mass of the tank due to the allowable capacity of cylindrical tank.

Find the Optimum Shape Design of Externally Pressurized Torispherical Dome Ends Based on Buckling Pressure by Using Imperialist Competitive Algorithm and Genetic Algorithm

In this paper, we used the Imperialist Competitive Algorithm (ICA) and Genetic Algorithm (GA) to find the minimum weight design of torispherical dome ends under external pressure load. According to fabrication and strength of material requirements, a group of compromised counters are selected and studied. Based on ASME Section VIII and BS5500 pressure vessel codes, a reasonable buckling pressure limit is proposed. Four-centered ellipse method is quite effective in designing and constructing the dome structure and it is used here to construct the torispherical dome ends. Two different size torispherical dome end models are selected and studied. Imperialist competitive algorithm is found to be very efficient and easy to use for the applications.