Cold-formed steel channel columns optimization with simulated annealing method

Moacir Kripka,Zacarias Martin Chamberlain Pravia 국제구조공학회 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.48 No.3

Cold-formed profiles have been largely used in the building industry because they can be easily produced and because they allow for a wide range of sections and thus can be utilized to meet different project requirements. Attainment of maximum performance by structural elements with low use of material is a challenge for engineering projects. This paper presents a numerical study aimed at minimizing the weight of lipped and unlipped cold-formed channel columns, following the AISI 2007 specification. Flexural, torsional and torsional–flexural buckling of columns was considered as constraints. The simulated annealing method was used for optimization. Several numerical simulations are presented and discussed to validate the proposal, in addition to an experimental example that qualifies its implementation. The ratios between lips, web width, and flange width are analyzed. Finally, it may be concluded that the optimization process yields excellent results in terms of cross-sectional area reduction.

Cold-formed steel channel columns optimization with simulated annealing method

Kripka, Moacir,Chamberlain Pravia, Zacarias Martin Techno-Press 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.48 No.3

Cold-formed profiles have been largely used in the building industry because they can be easily produced and because they allow for a wide range of sections and thus can be utilized to meet different project requirements. Attainment of maximum performance by structural elements with low use of material is a challenge for engineering projects. This paper presents a numerical study aimed at minimizing the weight of lipped and unlipped cold-formed channel columns, following the AISI 2007 specification. Flexural, torsional and torsional-flexural buckling of columns was considered as constraints. The simulated annealing method was used for optimization. Several numerical simulations are presented and discussed to validate the proposal, in addition to an experimental example that qualifies its implementation. The ratios between lips, web width, and flange width are analyzed. Finally, it may be concluded that the optimization process yields excellent results in terms of cross-sectional area reduction.

Assessment of Photovoltaic Potentials in Brazil Using Solar Resource Map

Adilson Moacir Becker Jr.,Yun, Chang-Yeol(윤창열),Jo, Dok-Ki(조덕기),Kim, Hyun-goo(김현구),Kang, Young-Heack(강용혁) 한국태양에너지학회 2013 한국태양에너지학회 학술대회논문집 Vol.2013 No.11

In order to analyze the photovoltaic potential in Brazil, the present study aims to simulate and compare the solar radiation and PV yield through the Brazilian and Korean Solar Map. five strategy points in Brazilian Territory and one point in Korea were selected, considering local characteristics and meteorological data. After that, a photovoltaic simulation had been proceeded by PV syst Software based on a PV Grid connected system with 1 MW rated power using the solar panel BP solar BP4175 (module type Mono-si PV and module efficiency of 13.9%). As the results, it can be noticed that the annual mean of daily horizontal global solar irradiation is between 4.20~6.70 kWh/㎡/d. The simulation shows that all studied sites present an interesting electricity yield. Brasilia and Teresina, located in Central West and Northeast, represent the highest energy production simulation(1,626and1,544 MWh/year, respectively). In doing so, Brazilian radiation reality can be easily compared to the most favorable countries around the world such as United States and India

Estimating Load Bearing Capacity of Some Agricultural Soils of the Cerrado Region Using Precompression Stress Data

Ayodele Ajayi,Moacir Dias Junior,Paula Sant’anna Moreira Pais,Curi Newton 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

Simulated squirrel search algorithm: A hybrid metaheuristic method and its application to steel space truss optimization

Mateus P. Pauletto,Moacir Kripka 국제구조공학회 2022 Steel and Composite Structures, An International J Vol.45 No.4

One of the biggest problems in structural steel calculation is the design of structures using the lowest possible material weight, making this a slow and costly process. To achieve this objective, several optimization methods have been developed and tested. Nevertheless, a method that performs very efficiently when applied to different problems is not yet available. Based on this assumption, this work proposes a hybrid metaheuristic algorithm for geometric and dimensional optimization of space trusses, called Simulated Squirrel Search Algorithm, which consists of an association of the wellestablished neighborhood shifting algorithm (Simulated Annealing) with a recently developed promising population algorithm (Squirrel Search Algorithm, or SSA). In this study, two models are tried, being respectively, a classical model from the literature (25-bar space truss) and a roof system composed of space trusses. The structures are subjected to resistance and displacement constraints. A penalty function using Fuzzy Logic (FL) is investigated. Comparative analyses are performed between the Squirrel Search Algorithm (SSSA) and other optimization methods present in the literature. The results obtained indicate that the proposed method can be competitive with other heuristics.

Structural optimization and proposition of pre-sizing parameters for beams in reinforced concrete buildings

Guilherme Fleith de Medeiros,Moacir Kripka 사단법인 한국계산역학회 2013 Computers and Concrete, An International Journal Vol.11 No.3

The aim of the present paper is to show the application of optimization strategies for the cost of beams in reinforced concrete buildings and to propose pre-sizing parameters. In order for these goals to be met, an optimization software program was developed. The program combines the analysis of structures by the grid model, reinforced concrete sizing, and the simulated annealing optimization heuristic. Sizing is compliant with the NBR 6118 (2007) Brazilian standard, according to which flexural, shearing, torsion, and web reinforcements and serviceability limit states (deflection and crack width limitation) are checked. Besides the dimensions of the situations mentioned above, the influence the cost of each material (steel, concrete and formwork) has on the overall cost of structures was also determined.

CO2 emission optimization of composite floor systems with cellular beams via metaheuristics algorithms

Gabrieli Fontes Silva,Moacir Kripka,Élcio Cassimiro Alves 국제구조공학회 2024 Structural Engineering and Mechanics, An Int'l Jou Vol.89 No.5

In this study, the optimization of the composite floor system with cellular beams is investigated. The objective function is the minimization of carbon dioxide (CO2) emissions and the optimal solution is defined by 19 design variables for the beam’s topology, beams fabricated process, steel deck characteristics, columns. The requirements of the ultimate and serviceability state limits are considered for the composite floor system design. The program is developed within the MATLAB platform. A number of the benchmark test problems of composite floor systems with full web beams are optimized with cellular beams to verify the reduction of total CO2 emission. The optimum results are obtained by Particle Swarm Optimization (PSO), Genetic Algorithm (GA) and Bonobo Algorithm (BO). A comparison of the performance of these algorithms shows that the BO algorithm has a higher search capability and results in better solutions than PSO and GA algorithms in the optimization of the composite floor system with the cellular beams and the use of cellular beams can reduce the total CO2 emissions of the floor above 20%.

Modified harmony search and its application to cost minimization of RC columns

Medeiros, Guilherme F.,Kripka, Moacir Techno-Press 2017 Advances in computational design Vol.2 No.1

This paper presents a variant of the Harmony Search Algorithm (HS) and its application to discrete optimization. The main proposed modifications regarding original HS are related to stopping criterion and reinitialization of population, called Harmony Memory. In order to investigate the efficiency of the algorithm, it was applied for obtaining optimal sections of reinforced concrete columns subjected to uniaxial flexural compression. To minimize the cost of the section, the amount and diameters of the reinforcement bars and the dimensions of the columns cross sections were considered as design variables. The obtained results were compared to those generated by other optimization methods. Since, to the examples, Harmony Search reached the same results achieved by Simulated Annealing, some additional analysis are presented in order to compare these methods regarding success rate and number of iterations to reach the optimum.

Minimizing environmental impact from optimized sizing of reinforced concrete elements

Jair F. Santoro,Moacir Kripka 사단법인 한국계산역학회 2020 Computers and Concrete, An International Journal Vol.25 No.2

The construction field must always explore sustainable ways of using its raw materials. Studying the environmental impact generated by reinforced concrete raw materials during their production and transportation can contribute to reducing this impact. This paper initially presents the carbon dioxide emissions from reinforced concrete raw materials, quantified per kilo of raw material and per cubic meter of concrete with different characteristic strengths, for southern Brazil. Subsequently, reinforced concrete elements were optimized to minimize their environmental impact and cost. It was observed that lower values of carbon dioxide emissions and cost savings are generated for less resistant concrete when the structural element is a beam, and that reductions in the cross section dimensions of the beams, sized based on the use of higher strength concrete, may not compensate for the increased environmental impact and costs. For the columns, the behavior differed, presenting lower values of carbon dioxide emissions and costs for higher concrete strengths. The proposed methodology, as well as the results obtained, can be used to support structural projects that have less impact on the environment.

Discrete sizing and layout optimization of steel truss-framed structures with Simulated Annealing Algorithm

Jéssica M. Bresolin,Zacarias M.C. Pravia,Moacir Kripka 국제구조공학회 2022 Steel and Composite Structures, An International J Vol.44 No.5

Structural design, in general, is developed through trial and error technique which is guided by standards criteria and based on the intuition and experience of the engineer, a context that leads to structural over-dimensioning, with uneconomic solutions. Aiming to find the optimal design, structural optimization methods have been developed to find a balance between cost, structural safety, and material performance. These methods have become a great opportunity in the steel structural engineering domain since they have as their main purpose is weight minimization, a factor directly correlated to the real cost of the structure. Assuming an objective function of minimum weight with stress and displacement constraints provided by Brazilian standards, the present research proposes the sizing optimization and combined approach of sizing and shape optimization, through a software developed to implement the Simulated Annealing metaheuristic algorithm. Therefore, two steel plane frame layouts, each admitting four typical truss geometries, were proposed in order to expose the difference between the optimal solutions. The assessment of the optimal solutions indicates a notable weight reduction, especially in sizing and shape optimization combination, in which the quantity of design variables is increased along with the search space, improving the efficiency of the optimal solutions achieved.