1,016 research outputs found

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

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    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

    Optimization-Based Evolutionary Data Mining Techniques for Structural Health Monitoring

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    In recent years, data mining technology has been employed to solve various Structural Health Monitoring (SHM) problems as a comprehensive strategy because of its computational capability. Optimization is one the most important functions in Data mining. In an engineering optimization problem, it is not easy to find an exact solution. In this regard, evolutionary techniques have been applied as a part of procedure of achieving the exact solution. Therefore, various metaheuristic algorithms have been developed to solve a variety of engineering optimization problems in SHM. This study presents the most applicable as well as effective evolutionary techniques used in structural damage identification. To this end, a brief overview of metaheuristic techniques is discussed in this paper. Then the most applicable optimization-based algorithms in structural damage identification are presented, i.e. Particle Swarm Optimization (PSO), Genetic Algorithm (GA), Imperialist Competitive Algorithm (ICA) and Ant Colony Optimization (ACO). Some related examples are also detailed in order to indicate the efficiency of these algorithms

    The Application of PSO in Structural Damage Detection: An Analysis of the Previously Released Publications (2005–2020)

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    The structural health monitoring (SHM) approach plays a key role not only in structural engineering but also in other various engineering disciplines by evaluating the safety and performance monitoring of the structures. The structural damage detection methods could be regarded as the core of SHM strategies. That is because the early detection of the damages and measures to be taken to repair and replace the damaged members with healthy ones could lead to economic advantages and would prevent human disasters. The optimization-based methods are one of the most popular techniques for damage detection. Using these methods, an objective function is minimized by an optimization algorithm during an iterative procedure. The performance of optimization algorithms has a significant impact on the accuracy of damage identification methodology. Hence, a wide variety of algorithms are employed to address optimization-based damage detection problems. Among different algorithms, the particle swarm optimization (PSO) approach has been of the most popular ones. PSO was initially proposed by Kennedy and Eberhart in 1995, and different variants were developed to improve its performance. This work investigates the objectives, methodologies, and results obtained by over 50 studies (2005-2020) in the context of the structural damage detection using PSO and its variants. Then, several important open research questions are highlighted. The paper also provides insights on the frequently used methodologies based on PSO, the computational time, and the accuracy of the existing methodologies

    Evolution of constrained layer damping using a cellular automaton algorithm

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    Constrained layer damping (CLD) is a highly effective passive vibration control strategy if optimized adequately. Factors controlling CLD performance are well documented for the flexural modes of beams but not for more complicated mode shapes or structures. The current paper introduces an approach that is suitable for locating CLD on any type of structure. It follows the cellular automaton (CA) principle and relies on the use of finite element models to describe the vibration properties of the structure. The ability of the algorithm to reach the best solution is demonstrated by applying it to the bending and torsion modes of a plate. Configurations that give the most weight-efficient coverage for each type of mode are first obtained by adapting the existing 'optimum length' principle used for treated beams. Next, a CA algorithm is developed, which grows CLD patches one at a time on the surface of the plate according to a simple set of rules. The effectiveness of the algorithm is then assessed by comparing the generated configurations with the known optimum ones

    Modelling and analysis of thin-walled structures for optimal design of composite wing

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    At present, the option for composite usage in aircraft components and the associated manufacturing process is largely based on experience, knowledge, benchmarking, and partly market driven. Consequently, a late realisation involving the design and manufacture, and an inevitable iterative design and validation process has led to high costs. The aim of this research is to develop a Knowledge-Based Optimisation Analysis Tool (K-BOAT) for optimal design of composite structures, subject to multi design constraints. Extensive study has been carried out on composite structure design, modelling, testing and analysis method to optimise a design of a composite wing panel during the preliminary design stage. This approach will allow the maximum knowledge input and interface between users (design engineers) with the design tool, rather than be left to the optimiser to provide a solution. The K-BOAT will build a set of parameters in the initial design, including the ratio of component dimensions, layers of different fibre angles, and bending-torsion coupling of a panel and a wing box. This framework offers a guideline for the design engineers to understand and expect the optimal solution of composite structures at the early design stage. This research focused on the optimal design of aircraft composite wing skin. The first level involved the initial analysis of the composite wing by using a low fidelity model based on thin-walled structural analysis method. The second level focused on the optimal design of the wing skin using the analytical method and validation using the high fidelity finite element (FE) method. In-house computing programs and commercial software are used for this level of study. In the third level, the FE model has been used to present a baseline structure to perform further detailed analysis and optimisation. The study is related to an industrially funded project. A case study of a practical wing structure in the project has indicated an improvement in aircraft aeroelastic stability by 30.5% from the initial design. Validation of the real industrial application proved that K-BOAT is applicable to the conceptual and preliminary phases in aircraft design

    Effects of a proper feature selection on prediction and optimization of drilling rate using intelligent techniques

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    One of the important factors during drilling times is the rate of penetration (ROP), which is controlled based on different variables. Factors affecting different drillings are of paramount importance. In the current research, an attempt was made to better recognize drilling parameters and optimize them based on an optimization algorithm. For this purpose, 618 data sets, including RPM, flushing media, and compressive strength parameters, were measured and collected. After an initial investigation, the compressive strength feature of samples, which is an important parameter from the rocks, was used as a proper criterion for classification. Then using intelligent systems, three different levels of the rock strength and all data were modeled. The results showed that systems which were classified based on compressive strength showed a better performance for ROP assessment due to the proximity of features. Therefore, these three levels were used for classification. A new artificial bee colony algorithm was used to solve this problem. Optimizations were applied to the selected models under different optimization conditions, and optimal states were determined. As determining drilling machine parameters is important, these parameters were determined based on optimal conditions. The obtained results showed that this intelligent system can well improve drilling conditions and increase the ROP value for three strength levels of the rocks. This modeling system can be used in different drilling operations

    A Comprehensive Survey on Particle Swarm Optimization Algorithm and Its Applications

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    Particle swarm optimization (PSO) is a heuristic global optimization method, proposed originally by Kennedy and Eberhart in 1995. It is now one of the most commonly used optimization techniques. This survey presented a comprehensive investigation of PSO. On one hand, we provided advances with PSO, including its modifications (including quantum-behaved PSO, bare-bones PSO, chaotic PSO, and fuzzy PSO), population topology (as fully connected, von Neumann, ring, star, random, etc.), hybridization (with genetic algorithm, simulated annealing, Tabu search, artificial immune system, ant colony algorithm, artificial bee colony, differential evolution, harmonic search, and biogeography-based optimization), extensions (to multiobjective, constrained, discrete, and binary optimization), theoretical analysis (parameter selection and tuning, and convergence analysis), and parallel implementation (in multicore, multiprocessor, GPU, and cloud computing forms). On the other hand, we offered a survey on applications of PSO to the following eight fields: electrical and electronic engineering, automation control systems, communication theory, operations research, mechanical engineering, fuel and energy, medicine, chemistry, and biology. It is hoped that this survey would be beneficial for the researchers studying PSO algorithms

    Strategies for using cellular automata to locate constrained layer damping on vibrating structures

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    It is often hard to optimise constrained layer damping (CLD) for structures more complicated than simple beams and plates as its performance depends on its location, the shape of the applied patch, the mode shapes of the structure and the material properties. This paper considers the use of cellular automata (CA) in conjunction with finite element analysis to obtain an efficient coverage of CLD on structures. The effectiveness of several different sets of local rules governing the CA are compared against each other for a structure with known optimum coverage-namely a plate. The algorithm which attempts to replicate most closely known optimal configurations is considered the most successful. This algorithm is then used to generate an efficient CLD treatment that targets several modes of a curved composite panel. To validate the modelling approaches used, results are also presented of a comparison between theoretical and experimentally obtained modal properties of the damped curved panel

    Response Ant Colony Optimization of End Milling Surface Roughness

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    Metal cutting processes are important due to increased consumer demands for quality metal cutting related products (more precise tolerances and better product surface roughness) that has driven the metal cutting industry to continuously improve quality control of metal cutting processes. This paper presents optimum surface roughness by using milling mould aluminium alloys (AA6061-T6) with Response Ant Colony Optimization (RACO). The approach is based on Response Surface Method (RSM) and Ant Colony Optimization (ACO). The main objectives to find the optimized parameters and the most dominant variables (cutting speed, feedrate, axial depth and radial depth). The first order model indicates that the feedrate is the most significant factor affecting surface roughness
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