The Experts below are selected from a list of 1035 Experts worldwide ranked by ideXlab platform

O. Hasançebi - One of the best experts on this subject based on the ideXlab platform.

  • OPTIMIZING SINGLE-SPAN STEEL TRUSS BRIDGES WITH SIMULATED ANNEALING
    2020
    Co-Authors: O. Hasançebi, Erkan Doğan
    Abstract:

    This study presents applications of a simulated annealing integrated solution algorithm to the optimum Design of single-span steel truss bridges subjected to gravity loadings. In the optimum Design process of a bridge the members are sized simultaneously as the coordinates of the upper chord nodes are determined such that the least Design weight is attained for the structure. The Design constraints and limitations are imposed in accordance with serviceability and strength provisions of ASD-AISC (Allowable Stress Design Code of American Institute of Steel Institution) specification. A numerical example is presented, where optimum Designs produced according to nine alternative topological forms of single-span truss bridges, namely Pratt, Parker, Baltimore, Pettit, K-Truss, Warren, Subdivided Warren, Quadrangular Warren and Whipple are compared for a selected span length of 600 ft (182.88 m) to quantify the influence of choice of a topological form on the final Design weight of the bridge.

  • EVALUATION OF TOPOLOGICAL FORMS FOR WEIGHT- EFFECTIVE OPTIMUM Design OF SINGLE-SPAN STEEL TRUSS BRIDGES
    2020
    Co-Authors: O. Hasançebi, E Doganb
    Abstract:

    This paper reports a comparative study on Design weight efficiency of single span steel truss bridge topologies subjected to gravity loads. The bridges configured according to nine distinct topological forms (namely, Pratt, Parker, Baltimore, Petit, K-Truss, Warren, Subdivided Warren, Quadrangular Warren and Whipple) are Designed for minimum weight under various span length requirements of single span truss bridges, and the results obtained with these topological forms are compared. The optimization process for each bridge topological form requires achieving optimal sizing of members as well as determining coordinates of the top chord nodes such that the least Design weight is attained for the bridge. The Design constraints and limitations are imposed according to serviceability and strength provisions of ASD-AISC (Allowable Stress Design Code of American Institute of Steel Institution) specification. The optimization algorithm employed is based on simulated annealing method.

  • A bat-inspired algorithm for structural optimization
    Computers & Structures, 2013
    Co-Authors: O. Hasançebi, Turker Teke, Onur Pekcan
    Abstract:

    Bat-inspired (BI) search is a recently developed numerical optimization technique that makes use of echolocation behavior of bats in seeking a Design space. This study intends to explore capabilities and potentials of this newly developed method in the realm of structural optimization. A novel algorithm is developed that employs basic principles of this method for structural optimization problems specifically. Performance of the proposed algorithm is measured using one benchmark as well as three practical truss structures that are sized for minimum weight subject to Stress, stability and displacement constraints according to American Institute of Steel Construction-Allowable Stress Design (AISC-ASD) specification. The numerical results demonstrate efficiency of the proposed algorithm in practical structural optimization.

  • Bat inspired algorithm for discrete size optimization of steel frames
    Advances in Engineering Software, 2013
    Co-Authors: O. Hasançebi, Serdar Carbas
    Abstract:

    Bat inspired (BI) algorithm is a recently developed metaheuristic optimization technique inspired by echolocation behavior of bats. In this study, the BI algorithm is examined in the context of discrete size optimization of steel frames Designed for minimum weight. In the optimum Design problem frame members are selected from available set of steel sections for producing practically acceptable Designs subject to strength and displacement provisions of American Institute of Steel Construction-Allowable Stress Design (AISC-ASD) specification. The performance of the technique is quantified using three real-size large steel frames under actual load and Design considerations. The results obtained provide a sufficient evidence for successful performance of the BI algorithm in comparison to other metaheuristics employed in structural optimization.

  • Discrete size optimization of steel trusses using a refined big bang–big crunch algorithm
    Engineering Optimization, 2013
    Co-Authors: O. Hasançebi, S. Kazemzadeh Azad
    Abstract:

    This article presents a methodology that provides a method for Design optimization of steel truss structures based on a refined big bang–big crunch (BB-BC) algorithm. It is shown that a standard formulation of the BB-BC algorithm occasionally falls short of producing acceptable solutions to problems from discrete size optimum Design of steel trusses. A reformulation of the algorithm is proposed and implemented for Design optimization of various discrete truss structures according to American Institute of Steel Construction Allowable Stress Design (AISC-ASD) specifications. Furthermore, the performance of the proposed BB-BC algorithm is compared to its standard version as well as other well-known metaheuristic techniques. The numerical results confirm the efficiency of the proposed algorithm in practical Design optimization of truss structures.

Mehmet Polat Saka - One of the best experts on this subject based on the ideXlab platform.

  • Comparison of non-deterministic search techniques in the optimum Design of real size steel frames
    Computers & Structures, 2010
    Co-Authors: O. Hasançebi, Serdar Carbas, Erkan Doğan, Ferhat Erdal, Mehmet Polat Saka
    Abstract:

    There is a noticeable increase in the emergence of non-deterministic search techniques that simulate natural phenomena into a numerical optimization technique in recent years. These techniques are used for developing structural optimization algorithms that are particularly effective for obtaining solutions to discrete programming problems. In this study amongst these techniques genetic algorithms, simulated annealing, evolution strategies, particle swarm optimizer, tabu search, ant colony optimization and harmony search are utilized to develop seven optimum Design algorithms for real size rigidly connected steel frames. The Design problems are formulated according to ASD-AISC (Allowable Stress Design Code of American Institute of Steel Institution).

  • Improving the performance of simulated annealing in structural optimization
    Structural and Multidisciplinary Optimization, 2010
    Co-Authors: Oğuzhan Hasançebi, Serdar Carbas, Mehmet Polat Saka
    Abstract:

    This study aims at improving the performance of simulated annealing (SA) search technique in real-size structural optimization applications with practical Design considerations. It is noted that a standard SA algorithm usually fails to produce acceptable solutions to such problems associated with its poor convergence characteristics and incongruity with theoretical considerations. In the paper novel approaches are developed and incorporated into the standard SA algorithm to eliminate the observed drawbacks of the technique. The performance of the resulting (improved) algorithm is investigated in conjunction with two numerical examples (a 304-member braced planar steel frame, and 132-member unbraced space steel frame) Designed according to provisions of the Allowable Stress Design (ASD) specification. In both examples, curves showing the variation of average acceptance probability parameter in standard and improved algorithms are plotted to verify usefulness and robustness of the integrated approaches.

Serdar Carbas - One of the best experts on this subject based on the ideXlab platform.

  • Bat inspired algorithm for discrete size optimization of steel frames
    Advances in Engineering Software, 2013
    Co-Authors: O. Hasançebi, Serdar Carbas
    Abstract:

    Bat inspired (BI) algorithm is a recently developed metaheuristic optimization technique inspired by echolocation behavior of bats. In this study, the BI algorithm is examined in the context of discrete size optimization of steel frames Designed for minimum weight. In the optimum Design problem frame members are selected from available set of steel sections for producing practically acceptable Designs subject to strength and displacement provisions of American Institute of Steel Construction-Allowable Stress Design (AISC-ASD) specification. The performance of the technique is quantified using three real-size large steel frames under actual load and Design considerations. The results obtained provide a sufficient evidence for successful performance of the BI algorithm in comparison to other metaheuristics employed in structural optimization.

  • ANT COLONY SEARCH METHOD IN PRACTICAL STRUCTURAL OPTIMIZATION
    Iran University of Science & Technology, 2011
    Co-Authors: O. Hasançebi, Serdar Carbas
    Abstract:

    This paper is concerned with application and evaluation of ant colony optimization (ACO) method to practical structural optimization problems. In particular, a size optimum Design of pin-jointed truss structures is considered with ACO such that the members are chosen from ready sections for minimum weight Design. The application of the algorithm is demonstrated using two Design examples with practical Design considerations. Both examples are formulated according to provisions of ASD-AISC (Allowable Stress Design Code of American Institute of Steel Institution) specification. The results obtained are used to discuss the computational characteristics of ACO for optimum Design of truss type structures.

  • Comparison of non-deterministic search techniques in the optimum Design of real size steel frames
    Computers & Structures, 2010
    Co-Authors: O. Hasançebi, Serdar Carbas, Erkan Doğan, Ferhat Erdal, Mehmet Polat Saka
    Abstract:

    There is a noticeable increase in the emergence of non-deterministic search techniques that simulate natural phenomena into a numerical optimization technique in recent years. These techniques are used for developing structural optimization algorithms that are particularly effective for obtaining solutions to discrete programming problems. In this study amongst these techniques genetic algorithms, simulated annealing, evolution strategies, particle swarm optimizer, tabu search, ant colony optimization and harmony search are utilized to develop seven optimum Design algorithms for real size rigidly connected steel frames. The Design problems are formulated according to ASD-AISC (Allowable Stress Design Code of American Institute of Steel Institution).

  • Improving the performance of simulated annealing in structural optimization
    Structural and Multidisciplinary Optimization, 2010
    Co-Authors: Oğuzhan Hasançebi, Serdar Carbas, Mehmet Polat Saka
    Abstract:

    This study aims at improving the performance of simulated annealing (SA) search technique in real-size structural optimization applications with practical Design considerations. It is noted that a standard SA algorithm usually fails to produce acceptable solutions to such problems associated with its poor convergence characteristics and incongruity with theoretical considerations. In the paper novel approaches are developed and incorporated into the standard SA algorithm to eliminate the observed drawbacks of the technique. The performance of the resulting (improved) algorithm is investigated in conjunction with two numerical examples (a 304-member braced planar steel frame, and 132-member unbraced space steel frame) Designed according to provisions of the Allowable Stress Design (ASD) specification. In both examples, curves showing the variation of average acceptance probability parameter in standard and improved algorithms are plotted to verify usefulness and robustness of the integrated approaches.

Erkan Doğan - One of the best experts on this subject based on the ideXlab platform.

  • OPTIMIZING SINGLE-SPAN STEEL TRUSS BRIDGES WITH SIMULATED ANNEALING
    2020
    Co-Authors: O. Hasançebi, Erkan Doğan
    Abstract:

    This study presents applications of a simulated annealing integrated solution algorithm to the optimum Design of single-span steel truss bridges subjected to gravity loadings. In the optimum Design process of a bridge the members are sized simultaneously as the coordinates of the upper chord nodes are determined such that the least Design weight is attained for the structure. The Design constraints and limitations are imposed in accordance with serviceability and strength provisions of ASD-AISC (Allowable Stress Design Code of American Institute of Steel Institution) specification. A numerical example is presented, where optimum Designs produced according to nine alternative topological forms of single-span truss bridges, namely Pratt, Parker, Baltimore, Pettit, K-Truss, Warren, Subdivided Warren, Quadrangular Warren and Whipple are compared for a selected span length of 600 ft (182.88 m) to quantify the influence of choice of a topological form on the final Design weight of the bridge.

  • Comparison of non-deterministic search techniques in the optimum Design of real size steel frames
    Computers & Structures, 2010
    Co-Authors: O. Hasançebi, Serdar Carbas, Erkan Doğan, Ferhat Erdal, Mehmet Polat Saka
    Abstract:

    There is a noticeable increase in the emergence of non-deterministic search techniques that simulate natural phenomena into a numerical optimization technique in recent years. These techniques are used for developing structural optimization algorithms that are particularly effective for obtaining solutions to discrete programming problems. In this study amongst these techniques genetic algorithms, simulated annealing, evolution strategies, particle swarm optimizer, tabu search, ant colony optimization and harmony search are utilized to develop seven optimum Design algorithms for real size rigidly connected steel frames. The Design problems are formulated according to ASD-AISC (Allowable Stress Design Code of American Institute of Steel Institution).

Andrzej S. Nowak - One of the best experts on this subject based on the ideXlab platform.

  • RISK ANALYSIS FOR CODE CALIBRATION
    Structural Safety, 2003
    Co-Authors: Andrzej S. Nowak
    Abstract:

    A procedure has been developed to calibrate safe O' indices for various types of structures. The load model is based on normal approximations of non-normal distributions at the Design point. For time varying loads, the basic time intervals are considered, with probabilities of occurrence in each interval and conditional distributions of intensity. Load and resistance factor format and Allowable Stress Design are considered. Computations were carried out for the National Building Code of Canada. Safety indices are presented in charts and tables. The results can be used to determine optimum values of resistance factors and/or safety factors.

  • LOAD AND RESISTANCE FACTOR Design CODE FOR WOOD BRIDGES
    1995
    Co-Authors: Andrzej S. Nowak, Michael A. Ritter
    Abstract:

    The development of a load and resistance factor Design (LRFD) edition of AASHTO's Standard Specifications for Highway Bridges is complete. A part of this effort involved the development of LRFD provisions for wood bridges. These new specifications include numerous changes and several significant departures from current Allowable Stress Design practices for wood bridges. The live load model is based on the statistical analysis of the actual traffic data. The Design load is a superposition of the traditional HS20 truck and lane loading. Dynamic load is applied to wooden components of the superstructure. Strength of material is based on the nominal values derived from in-grade tests, specified for wet-use conditions and 2-month live load duration. The resistance factors are determined consistently for all the limit states considered. The major changes in the approach to summarize the Design provisions are presented.

  • LRFD Provisions for Wood Bridges
    1994
    Co-Authors: Michael A. Ritter, Andrzej S. Nowak
    Abstract:

    A project to develop a load and resistance factor Design (LRFD) edition of the American Association of State Highway and Transportation Officials (AASHTO) Standard Specifications for Highway Bridges is complete. A part of this effort involved the development of LRFD provisions for wood bridges. These new specifications include numerous changes and several significant departures from current Allowable Stress Design practices for wood bridges.