scholarly journals Optimal Design of Steel-Concrete Composite I-girder Bridges Using Three Meta-Heuristic Algorithms

2018 ◽  
Author(s):  
Ali Kaveh ◽  
Mohammad Mahdi Motesadi Zarandi
Keyword(s):  
Optimal Design ◽  
Heuristic Algorithms ◽  
Particle System ◽  
Cost Optimization ◽  
Optimized Design ◽  
Code Of Practice ◽  
Longitudinal Stiffener ◽  
Girder Bridges ◽  
Colliding Bodies Optimization ◽  
Continuous And Discrete Variables

Bridges are among very important structures in engineering, due to their rather high cost, and this is why optimization of these structures is a challenging problem. In this paper, optimal design of steel-concrete composite I-girder bridges is performed. Three recently developed meta-heuristic algorithms consisting of Colliding Bodies Optimization (CBO), Enhanced Colliding Bodies Optimization (ECBO) and Vibration Particle System (VPS) are utilized for the first time in the optimal design of steel-concrete I-girder bridges. Both continuous and discrete variables are utilized in the process of optimization. Performance and the convergence histories of these algorithms are compared. In order to have a suitable comparison between these algorithms with previous algorithms, PSO is used and results are displayed. This paper focuses on cost optimization the bridges. Furthermore constraints include all of requirements of the code of practice for design. The comparative study has shown that VPS algorithm has better performance than CBO and ECBO. However, all three algorithms act in a way that the final optimized design does not need the addition of the longitudinal stiffener.

scholarly journals Optimal Design of Jacket Supporting Structures for Offshore Wind Turbines Using CBO and ECBO Algorithms

2017 ◽  
Author(s):  
Ali Kaveh ◽  
Sepehr Sabeti
Keyword(s):  
Optimal Design ◽  
Wind Turbines ◽  
Heuristic Algorithms ◽  
Limit State ◽  
Offshore Wind ◽  
Ultimate Limit State ◽  
Offshore Wind Turbines ◽  
Supporting Structure ◽  
Colliding Bodies Optimization ◽  
Resultant Forces

Structural optimization of offshore wind turbines is a tedious task due to the complexity of the problem. However, in this article, this problem is tackled using two meta-heuristic algorithms - Colliding Bodies Optimization (CBO) and its enhanced version (ECBO) - for a jacket supporting structure. The OC4 reference jacket is chosen as a case study to validate the methods utilized in this research. The jacket supporting structure is modeled in MATLAB and its optimal design is performed while both Ultimate Limit State (ULS) and frequency constraints are considered. In the present study, it is presumed that both wind and wave phenomena act in the same horizontal direction. As a result, all resultant forces and moments will act in-plane and the substructure can therefore be modeled in 2D space. Considerable weight reduction is obtained during the optimization process while fulfilling all constraints. 

Comparison of a Thermoacoustic Refrigerator Stack Performance: Mylar Spiral, Celcor Substrates and 3D Printed Stacks

2019 ◽  
Vol 27 (03) ◽  
pp. 1950021
Author(s):  
N. A. Zolpakar ◽  
N. Mohd-Ghazali
Keyword(s):  
Optimal Design ◽  
Temperature Difference ◽  
Cooling System ◽  
Coefficient Of Performance ◽  
Design Parameters ◽  
Optimized Design ◽  
Multi Objective Genetic Algorithm ◽  
Potential Alternative ◽  
3D Printed ◽  
Thermoacoustic Refrigeration

Although the thermoacoustic refrigeration (TAR) system has been recognized as a potential alternative environmentally cooling system, the low coefficient of performance (COP) has yet to make it marketable. One major factor contributing towards the low COP is the fabrication method applied to the stack component which is the most important component in the TAR. In this paper, comparison of the performance of a (i) 3D printed stack, (ii) a hand fabricated Mylar stack and (iii) an off-the-shelf Celcor substrates stack has been done; these being based on optimized design parameters using Multi-Objective Genetic Algorithm (MOGA). The performance is determined from the temperature attained at the cold end of the stack and the temperature difference across the stack. Experimental results showed that the 3D printed stack has the best performance by achieving a temperature, [Formula: see text]C at the cold end and a temperature difference of [Formula: see text]C across the stack, about 60% of the designed temperature difference even though the fabricated 3D printed stack deviated from the optimal design due to fabrication constraint as compared to that of the Mylar stack which was closer to the optimal design. This 3D printing of the stack promises a big potential in the improvement of the TAR performance because of the consistency achievable with the precise dimensions of the stack.

Balancing Bandwidth Utilization and Interrupts: Two Heuristic Algorithms for the Optimized Design of Automotive CPS

2020 ◽  
Vol 16 (4) ◽  
pp. 2382-2392
Author(s):  
Yong Xie ◽  
Gang Zeng ◽  
Ryo Kurachi ◽  
Xin Peng ◽  
Guoqi Xie ◽  
...  
Keyword(s):  
Heuristic Algorithms ◽  
Optimized Design ◽  
Bandwidth Utilization

Comparison of four meta-heuristic algorithms for optimal design of double-layer barrel vaults

2018 ◽  
Vol 33 (3-4) ◽  
pp. 115-123
Author(s):  
Ali Kaveh ◽  
Majid Ilchi Ghazaan ◽  
Soroush Mahjoubi
Keyword(s):  
Optimal Design ◽  
Double Layer ◽  
Heuristic Algorithms ◽  
Size Optimization ◽  
Community Centers ◽  
Cross Sectional ◽  
Long Span ◽  
Design Variables ◽  
Rail Station ◽  
Barrel Vaults

Barrel vaults are effective semi-cylindrical forms of roof systems that are widespread for multipurpose facilities including warehouse, rail station, pools, sports center, airplane hungers, and community centers because of providing long-span and economical roof with significant amount of space underneath. In the present study, size optimization of double-layer barrel vaults with different configurations is studied. Four recently developed algorithms consisting of the CBO, ECBO, VPS, and MDVC-UVPS are employed and their performances are compared. The structures are subjected to stress, stability, and displacement limitations according to the provisions of AISC-ASD. The design variables are the cross-sectional areas of the bar elements which are selected from steel pipe sections. The numerical results indicate that the MDVC-UVPS outperforms the other algorithms in finding optimal design in all examples.

A methodology for an optimal design of physical parameters, positions, and viscoelastic materials of simple dynamic absorbers for passive vibration control

2019 ◽  
Vol 25 (6) ◽  
pp. 1133-1147 ◽  
Author(s):  
Francielly Elizabeth de Castro Silva ◽  
Carlos Alberto Bavastri
Keyword(s):  
Optimal Design ◽  
Vibration Control ◽  
Passive Control ◽  
Optimization Technique ◽  
Physical Parameters ◽  
Vibration Absorbers ◽  
Viscoelastic Materials ◽  
Different Temperatures ◽  
Mechanical Devices ◽  
Continuous And Discrete Variables

Dynamic vibration absorbers are simple mechanical devices that are attached to a structure aiming at reducing vibration levels. Designing such devices for vibration control of mechanical systems using viscoelastic materials results in low costs, easy construction, and higher efficacy due to their ability to dissipate vibration energy. In this context, the present study aims at developing a methodology for an optimal design of a set of viscoelastic dynamic absorbers considering their natural frequencies, the positions to attach them onto the structure to be controlled, and the viscoelastic materials as variables to be optimized for different working temperatures. The optimal configuration is obtained by applying a hybrid optimization technique, which uses genetic algorithms (considering continuous and discrete variables in the same design vector) aiming at approximating the global minimum point and, subsequently, a nonlinear programming method (simplex based on the Nelder–Mead method) to perform a local search. An example of dynamic absorber design to reduce vibration levels in a one-degree-of-freedom (DOF) system and on a steel plate (multiple-DOFs) is presented. The results show the efficacy of the methodology for passive control of vibrations acting on a broadband of frequencies and different temperatures.

A Structure Optimization for Hooklift Arm Device Based on the Genetic Algorithm

2012 ◽  
Vol 455-456 ◽  
pp. 1504-1508
Author(s):  
Huan Ming Chen ◽  
Da Wei Liu
Keyword(s):  
Genetic Algorithm ◽  
Optimal Design ◽  
Parameter Optimization ◽  
Structure Optimization ◽  
Optimization Method ◽  
Optimized Design ◽  
Design Decision ◽  
Original Design ◽  
Multi Objective ◽  
Engineering Constraint

Based on the theory of FEM, the hooklift arm is modeled with the FEM software, and the structure of the device is optimized with genetic algorithm in a multi-objective/multi-parameter optimization environment, which results in an optimal design decision of the hooklift arm device under the engineering constraint. Comparison between optimized design decision and original design decision shows that the optimization is correct and the proposed multi-objective/multi-parameter optimization method is effective in improving the hooklift arm device.

Optimal design of nonlinear large-scale suspendome using cascade optimization

2017 ◽  
Vol 33 (1) ◽  
pp. 3-18 ◽  
Author(s):  
Ali Kaveh ◽  
Masoud Rezaei ◽  
MR Shiravand
Keyword(s):  
Optimal Design ◽  
Large Scale ◽  
Simple Procedure ◽  
Geometry Optimization ◽  
Steel Structures ◽  
Optimization Method ◽  
Scale Space ◽  
Cross Sectional ◽  
Colliding Bodies Optimization ◽  
Design Variables

Large-scale suspendomes are elegant architectural structures which cover a vast area with no interrupting columns in the middle. These domes have attractive shapes which are also economical. Domes are built in a wide variety of forms. In this article, an algorithm is developed for optimum design of domes considering the topology, geometry, and size of member section using the cascade-enhanced colliding bodies optimization method. In large-scale space steel structures, a large number of design variables are involved. The idea of cascade optimization allows a single optimization problem to be tackled in a number of successive autonomous optimization stages. The variables are the optimum height of crown and tubular sections of these domes, the initial strain, the length of the struts, and the cross-sectional areas of the cables in the tensegrity system of domes. The number of joints in each ring and the number of rings are considered for topology optimization of ribbed and Schwedler domes. Weight of the dome is taken as the objective function for minimization. A simple procedure is defined to determine the configuration of the domes. The design constraints are considered according to the provisions of Load and Resistance Factor Design–American Institute of Steel Constitution. In order to investigate the efficiency of the presented method, a large-scale suspendome with more than 2266 members is investigated. Numerical results show that the utilized method is an efficient tool for optimal design of large-scale domes. Additionally, in this article, a topology and geometry optimization for two common ribbed and Schwedler domes are performed to find their optimum graphs considering various spans.

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