• Title/Summary/Keyword: Strength Optimization

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Research for 2MW Wind Turbine Tower Shell Design Optimization (2MW급 풍력발전기 타워 쉘 최적 설계)

  • Hong, Hyeok-Soo;Park, Jin-Il;Bang, Jo-Hyug;Ryu, Ji-Yune;Kim, Doo-Hoon
    • New & Renewable Energy
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    • v.2 no.4 s.8
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    • pp.19-26
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    • 2006
  • Tower shell design is very important because tower takes about 20% of overall wind turbine cost. This paper contains procedure of tower analysis and tower shell thickness optimization concept. Some of requirements like eigenfrequency and buckling evaluated by numerical method. But strength and fatigue can be derived by mathematical method simply. Using this procedure, tower shell thickness can be designed without repetition of complicated calculation.

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Optimum Mix Proportion and Mechanical Properties of Rain Garden Structure Concrete using Recycled Coarse Aggregate, Hwang-Toh, Blast Furnace Slag and Jute Fiber (순환굵은골재, 황토, 고로슬래그 미분말 및 마섬유를 사용한 레인가든 구조물 콘크리트의 최적배합설계 및 역학적 특성)

  • Kim, Dong-Hyun;Park, Chan Gi
    • Journal of The Korean Society of Agricultural Engineers
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    • v.55 no.3
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    • pp.25-33
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    • 2013
  • In this study, the optimum mix proportions of rain garden structure concrete were decided and the mechanical properties were evaluated. Experimental parameters were blast furnace slag, hwang-toh, recycled aggregates and natural jute fibers. The target compressive strength and chloride ion penetration were more than 24 MPa and less than 1000 coulombs, respectively. The response surface method was used for statistical optimization of experimental results. The optimal mixing ratios of the blast furnace slag, hwang-toh, recycled coarse aggregate and jute fiber volume fraction were determined 59.98 %, 8.74 %, 12.12 % and 0.2 %, respectively. The compressive strength, flexural strength and chloride ion penetration test results of optimum mix ratio showed that the 24.56 MPa, 3.88 MPa and 999.08 columbs, respectively.

The Design of Manufacturing Process Optimization for Aluminum Laser Welding using Remote Scanner (원격 스캐너를 이용한 알루미늄 레이저 용접에 대한 생산 공정 최적화 설계)

  • Kim, Dong-Yoon;Park, Young-Whan
    • Journal of Welding and Joining
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    • v.29 no.6
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    • pp.82-87
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    • 2011
  • In this study, we conducted laser welding by using remote scanner that is 5J32 aluminum alloy to observe the mechanical properties and optimize welding process parameters. As the control factors, laser incident angle, laser power and welding speed were set and as the result of weldablility, tensile shear tests were performed. ANOVA (Analysis of Variation) was also carried out to identify the influence of process variables on tensile shear strength. Strength estimation models were suggested using regression alnalysis and 2nd order polynomial model had the best estimation performance. In addition optimal welding condition was determined in terms with wedalility and productivity using objective function and fitness function. Final optimized welding condition was laser power was 4 kW, and welding speed was 4.6 m/min.

Ensemble techniques and hybrid intelligence algorithms for shear strength prediction of squat reinforced concrete walls

  • Mohammad Sadegh Barkhordari;Leonardo M. Massone
    • Advances in Computational Design
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    • v.8 no.1
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    • pp.37-59
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    • 2023
  • Squat reinforced concrete (SRC) shear walls are a critical part of the structure for both office/residential buildings and nuclear structures due to their significant role in withstanding seismic loads. Despite this, empirical formulae in current design standards and published studies demonstrate a considerable disparity in predicting SRC wall shear strength. The goal of this research is to develop and evaluate hybrid and ensemble artificial neural network (ANN) models. State-of-the-art population-based algorithms are used in this research for hybrid intelligence algorithms. Six models are developed, including Honey Badger Algorithm (HBA) with ANN (HBA-ANN), Hunger Games Search with ANN (HGS-ANN), fitness-distance balance coyote optimization algorithm (FDB-COA) with ANN (FDB-COA-ANN), Averaging Ensemble (AE) neural network, Snapshot Ensemble (SE) neural network, and Stacked Generalization (SG) ensemble neural network. A total of 434 test results of SRC walls is utilized to train and assess the models. The results reveal that the SG model not only minimizes prediction variance but also produces predictions (with R2= 0.99) that are superior to other models.

Study on Dissimilar Friction Welding Optimization of Heat Resisting Steels for Turbine and Real-Time Quality Evaluation by Ascoustic Emission(I) - FRW Optimization (터빈용 내열강의 이종재 마찰용접 최적화와 AE에 의한 품질 실시간 평가에 관한 연구(I) - 마찰용접 최적화)

  • Park, Hyung-Dong;Oh , Sae Kyoo;Kwon, Sang-Woo
    • Journal of Ocean Engineering and Technology
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    • v.13 no.3 s.33
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    • pp.83-91
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    • 1999
  • Taking a view of joining by welding the IN713C to SCM440 and SCM415 steel in production of turbochargers, the frictin welding process may be utilized as a new approach for joining them of other conventional welding processes. It is because the friction welding has more technical and technical and economic advantages than the other welding processes. As this welding process has the characteristics such as curtaliment of production time and materials and cost reduction, etc.. So, this paper deals with determining the preper friction welding condition and analyzing various mechanical properties of friction welded joints of the super heat resisting steel to alloy stee(IN713C to SCM440 and SCM415). And the in-process real-time weld quality evaluation technique by acoustic emission during friction welding of IN713C to SCM440 and SCM415 steels with higher confidence and relibility has been much required even though it might be the first trial approach for developing it. Then, this first study aimed to develop the optimization of dissimilar friction welding of heat resisting steels (INC713 to SCM440, SCM415) for turbine, considering on strength and toughness.

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Congestion Management in Deregulated Power System by Optimal Choice and Allocation of FACTS Controllers Using Multi-Objective Genetic Algorithm

  • Reddy, S. Surender;Kumari, M. Sailaja;Sydulu, M.
    • Journal of Electrical Engineering and Technology
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    • v.4 no.4
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    • pp.467-475
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    • 2009
  • Congestion management is one of the technical challenges in power system deregulation. This paper presents single objective and multi-objective optimization approaches for optimal choice, location and size of Static Var Compensators (SVC) and Thyristor Controlled Series Capacitors (TCSC) in deregulated power system to improve branch loading (minimize congestion), improve voltage stability and reduce line losses. Though FACTS controllers offer many advantages, their installation cost is very high. Hence Independent System Operator (ISO) has to locate them optimally to satisfy a desired objective. This paper presents optimal location of FACTS controllers considering branch loading (BL), voltage stability (VS) and loss minimization (LM) as objectives at once using GA. It is observed that the locations that are most favorable with respect to one objective are not suitable locations with respect to other two objectives. Later these competing objectives are optimized simultaneously considering two and three objectives at a time using multi-objective Strength Pareto Evolutionary Algorithms (SPEA). The developed algorithms are tested on IEEE 30 bus system. Various cases like i) uniform line loading ii) line outage iii) bilateral and multilateral transactions between source and sink nodes have been considered to create congestion in the system. The developed algorithms show effective locations for all the cases considered for both single and multiobjective optimization studies.

An Application of Topology Optimization for Strength Design of FPSO Riser Support Structure (FPSO Riser 지지 구조의 강도설계에 대한 위상최적화 응용)

  • Song, Chang-Yong;Choung, Joon-Mo;Shim, Chun-Sik
    • Journal of Ocean Engineering and Technology
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    • v.24 no.1
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    • pp.153-160
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    • 2010
  • This paper deals with the topology optimized design of the riser support structures for floating production storage and offloading units (FPSOs) under global and local loading conditions. For a preliminary study and validation of the numerical approach, a simplified plate under static loading is first evaluated with the representative topology optimization methods, the Homogenization Design Method (HDM) and Density Method (DM) or Simple Isotropic Material with Penalization (SIMP). In the context of the corresponding riser support structures, the design problem is formulated such that structure shapes based on design domain variables are determined by minimizing the compliance subject to a mass target, considering the stress criterion. An initial design model is generated based on an actual FPSO riser support configuration. The topology optimization results present improved design performances under various loading conditions, while staying within the allowable limit of the offshore area.

Design Optimization of the Rib Structure of a 5-Axis Multi-functional Machine Tool Considering Static Stiffness (정강성을 고려한 5축 복합가공기의 리브 구조 최적설계)

  • Kim, Seung-Gi;Kim, Ji-Hoon;Kim, Se-Ho;Youn, Jae-Woong
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.25 no.5
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    • pp.313-320
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    • 2016
  • The need for high-strength, multi-axis, and multi-functional machine tools has recently increased because of part complexity and workpiece strength. However, most of the machine tool manufacturers rely on experience for a detailed design because of the shortcomings in the existing design technology. This study uses a topology optimization method to more effectively design a large multi-functional machine tool considering static stiffness. The ram, saddle, and column parts are important structures in a machine tool. Hence, they are selected for the finite element method analysis. Based on this analysis, the optimized internal rib structure for those parts is designed for desirable rigidity and weight. This structure could possibly provide the required design technology for machine tool manufacturers.

Optimal seismic retrofit design method for asymmetric soft first-story structures

  • Dereje, Assefa Jonathan;Kim, Jinkoo
    • Structural Engineering and Mechanics
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    • v.81 no.6
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    • pp.677-689
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    • 2022
  • Generally, the goal of seismic retrofit design of an existing structure using energy dissipation devices is to determine the optimum design parameters of a retrofit device to satisfy a specified limit state with minimum cost. However, the presence of multiple parameters to be optimized and the computational complexity of performing non-linear analysis make it difficult to find the optimal design parameters in the realistic 3D structure. In this study, genetic algorithm-based optimal seismic retrofit methods for determining the required number, yield strength, and location of steel slit dampers are proposed to retrofit an asymmetric soft first-story structure. These methods use a multi-objective and single-objective evolutionary algorithms, each of which varies in computational complexity and incorporates nonlinear time-history analysis to determine seismic performance. Pareto-optimal solutions of the multi-objective optimization are found using a non-dominated sorting genetic algorithm (NSGA-II). It is demonstrated that the developed multi-objective optimization methods can determine the optimum number, yield strength, and location of dampers that satisfy the given limit state of a three-dimensional asymmetric soft first-story structure. It is also shown that the single-objective distribution method based on minimizing plan-wise stiffness eccentricity turns out to produce similar number of dampers in optimum locations without time consuming nonlinear dynamic analysis.

Optimum design of steel space structures using social spider optimization algorithm with spider jump technique

  • Aydogdu, Ibrahim;Efe, Perihan;Yetkin, Metin;Akin, Alper
    • Structural Engineering and Mechanics
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    • v.62 no.3
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    • pp.259-272
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    • 2017
  • In this study, recently developed swarm intelligence algorithm called Social Spider Optimization (SSO) approach and its enhanced version of SSO algorithm with spider jump techniques is used to develop a structural optimization technique for steel space structures. The improved version of SSO uses adaptive randomness probability in generating new solutions. The objective function of the design optimization problem is taken as the weight of a steel space structure. Constraints' functions are implemented from American Institute of Steel Construction-Load Resistance factor design (AISC-LRFD) and Ad Hoc Committee report and practice which cover strength, serviceability and geometric requirements. Three steel space structures are optimized using both standard SSO and SSO with spider jump (SSO_SJ) algorithms and the results are compared with those available in the literature in order to investigate the performance of the proposed algorithms.