Moacir Kripka

Scopus Publications

Integrated optimization framework for fire-resilient and sustainable hybrid steel-concrete composite footbridges
Fernando Luiz Tres Junior, Guilherme Fleith de Medeiros, Moacir Kripka, Víctor Yepes
Engineering Structures, 2026
While structural optimization is essential for sustainable design, its potential for complex structures to enhance resilience to extreme events remains underexplored. Hybrid steel-concrete systems offer significant performance benefits, yet their efficiency under these critical scenarios requires further investigation. This study addresses these gaps by proposing a straightforward and integrated multi-objective optimization framework that treats fire performance as a primary design driver alongside cost, environmental impact, and pedestrian comfort. The framework is demonstrated on a 20 m simply supported steel-concrete composite footbridge composed of two hybrid welded I-girders and a 3 m-wide concrete deck, with design variables defined by geometry, material strengths, and the degree of composite interaction. Results demonstrate that hybrid girders are highly effective across all scenarios, reducing total costs relative to conventional girders while maintaining comparable environmental performance. These benefits are particularly significant for designs that prioritize dynamic efficiency, where cost reductions reach up to 21% even under high comfort requirements. Optimal configurations typically employ lower-strength steel for the web and higher-strength steel for the flanges, with a yield strength ratio of around 1.6 as a practical design recommendation. Fire safety is improved with more compact girders, whereas slender geometries enhance dynamic performance, highlighting the distinct nature of these objectives. Incorporating fire performance considerations at the conceptual design stage leads to safer, more resilient, and cost-effective footbridges with minimal environmental impact. Overall, the proposed framework promotes performance-based structural design by supporting informed decision-making across multiple competing criteria and extreme conditions. • Novel framework enables multiobjective optimization including fire. • Fire optimal sections are compact, dynamic optimal sections are slender. • Hybrid girders reduce cost by 21% with equivalent environmental impact. • Yield strength ratio of 1.6 identified as a practical hybrid sizing guideline.
Parametric Analysis in the Optimization Design of Composite Cellular Beams †
Maria Célia Loss Brandão, Lorena Yepes-Bellver, Moacir Kripka, Élcio Cassimiro Alves
Infrastructures, 2026
This study aims to present a parametric analysis in the optimization problem for steel-concrete composite cellular beams with steel deck slabs. A comparative analysis was carried out considering two scenarios, namely, (i) in the first scenario, the slab span and applied loads were varied, adopting slab configurations from a manufacturer’s catalog for spans of 10 m to 20 m with a step of 2.5 m; (ii) in the second scenario, the same span and loading conditions were considered; however, slab optimization was performed by introducing reinforcement in order to evaluate the resulting impacts on the structural design. In both analyzed scenarios, the objective function was defined as the composite system’s CO2 emissions. The design constraints were defined based on literature recommendations, and to solve the optimization problem, the Particle Swarm Optimization (PSO) algorithm was also adopted. The results demonstrate that the PSO algorithm was effective in identifying optimal solutions and that the introduction of slab reinforcement, combined with optimal design, led to CO2 emission reductions of up to 25% at the highest load levels analyzed.
Optimized and Sustainable Structural Design
Moacir Kripka
Springer Tracts in Civil Engineering, 2026
Artificial Neural Networks Model for Natural Frequency Prediction in Reinforced Concrete Slabs
Moacir Kripka, Bruno Marangoni, Lucimara Bragagnolo, Zacarias M. C. Pravia
Studies in Systems Decision and Control, 2026
Life-cycle environmental impact optimization of an RC-THVS composite frame for sustainable construction
Iván Negrin, Moacir Kripka, Víctor Yepes
Engineering Structures, 2025
This study investigates the benefits of Life-Cycle Environmental Impact Optimization (LCEIO) in structural engineering, focusing on the RC-THVS composite typology as a sustainable alternative for frame-building construction. This innovative structural system integrates reinforced concrete (RC) columns with Transversely Hybrid Variable Section (THVS) steel girders serving as beam elements. The optimization problem is formulated to optimize the Global Warming Potential of the building structure during its life cycle. A novel LHS-CINS algorithm is introduced to solve the formulated optimization problems efficiently. Results show that LCEIO reduces environmental impact significantly, with optimized structures achieving up to a 32 % reduction in emissions compared to traditionally designed buildings. The most substantial improvement occurs in the manufacturing phase, where THVS girders lower emissions by up to 70 % compared to traditional I-section profiles. Additionally, maintenance-related impacts decrease by 45 % due to the girders' optimized tapered geometry. When comparing optimized solutions, rigid-joint composite typologies outperform RC systems in low-aggressiveness environments, reducing life-cycle emissions by 30 %. In highly aggressive environments, composite structures remain more sustainable than RC ones, although maintenance impacts are accentuated. Beyond individual component performance, THVS girders contribute to overall structural efficiency by reducing self-weight, thereby lowering axial loads on columns and foundations. Moreover, when slabs and walls are integrated into the superstructure, composite typologies further enhance system efficiency, cutting emissions by up to 42 % compared to bare frame models. The findings emphasize the capability of LCEIO and composite configurations to design more sustainable, efficient, and environmentally responsible building solutions. • LCEIO of a novel composite frame building structure is performed. • Optimized composite buildings achieve up to 30 % reductions in life-cycle emissions. • Lightweight THVS girders cut axial loads, reducing full assembly impact. • Composite frames lower emissions by 42 % when integrated with slabs and structural walls.
Manufacturing cost optimization of welded steel plate I-girders integrating hybrid construction and tapered geometry
Iván Negrin, Moacir Kripka, Víctor Yepes
International Journal of Advanced Manufacturing Technology, 2025
Steel plate I-girders are widely used in the construction industry worldwide. While numerous studies have explored ways to enhance their benefits, few have simultaneously optimized both key mechanical components—geometry and material—to develop novel and more efficient typologies. This research employs metaheuristic optimization to explore alternatives to traditional I-girders, formulating optimization problems that integrate geometric and material variables in both transverse and longitudinal planes. The objective is to minimize manufacturing costs, accounting for material expenses and seven key production activities such as welding, cutting, or painting, while ensuring compliance with Eurocode 3 specifications. The results indicate that material selection dominates in short-span girders, whereas geometric optimization becomes more critical for longer spans. The most cost-effective solution identified is the transversely hybrid with variable section (THVS) girder, which features tapered geometry and hybrid material distribution between the flanges and the web. Based on these findings, practical design recommendations are provided, including optimal span-to-depth ratios, hybrid ratios, taper angles, and transition positions for variable cross-section configurations. A proposed design methodology incorporating these recommendations is validated through a case study, demonstrating that THVS elements can reduce costs by up to 70% compared to traditional designs. However, challenges related to material availability, fabrication complexity, and local buckling risks must be addressed to fully realize the potential of these designs. Future research should prioritize FEA and experimental testing to refine these typologies and update design codes to better account for tapered and hybrid girders.
Experimental study of human-induced vibrations on glued laminated timber floors
Jéssica Maria Bresolin, Moacir Kripka, Zacarias Martin Chamberlain Pravia
Structures, 2025
An integrated framework for optimization-based robust design to progressive collapse of RC skeleton buildings incorporating soil-structure interaction effects
Iván Negrin, Ernesto Chagoyén, Moacir Kripka, Víctor Yepes
Innovative Infrastructure Solutions, 2025
Structural optimization is crucial in advancing simulation-based engineering by potentially improving design sustainability and resilience. However, optimizing for specific criteria often results in inefficient or vulnerable designs when evaluated against other critical factors. Among these factors, structural safety—particularly buildings’ resistance to progressive collapse (PC)—has garnered increasing attention. Despite significant experimental and numerical studies, the integration of PC resistance into structural optimization remains underexplored. This paper introduces a computational framework, termed Optimization-based Robust Design to Progressive Collapse (ObRDPC), combining simulation-based optimization techniques with PC-resistant design principles. The methodology also incorporates an automated strategy for considering soil-structure interaction (SSI), an aspect usually ignored in optimization-based structural design. The proposed framework is validated through five case studies involving 3D reinforced concrete skeleton buildings, each subjected to two load-bearing element removal scenarios using the Alternate Path method. Results demonstrate the pivotal role of SSI in achieving efficient designs and accurately assessing PC robustness. Neglecting SSI can lead to material usage differences of up to 24.29% and 22.09% in superstructure design following corner and exterior column failures, respectively. Findings also indicate that increasing the number of stories enhances structural robustness. In contrast, buildings with 8-meter spans may incur over 50% higher environmental impact to withstand the failure of a load-bearing element. The study also provides insights into load redistribution mechanisms that beams, columns, and foundations adopt to improve structural resilience. Finally, practical design guidelines are provided to support the replicability and real-world application of the framework, promoting sustainable and resilient infrastructure.
Design optimization of a composite typology based on RC columns and THVS girders to reduce economic cost, emissions, and embodied energy of frame building construction
Iván Negrin, Moacir Kripka, Víctor Yepes
Energy and Buildings, 2025
• A novel composite frame combining RC columns and THVS steel girders is introduced. • Optimized designs reduce costs by 6% and emissions/energy by 16% for shorter spans. • Pinned connections reduce emissions by 6% for longer spans with economic gains. • THVS girders’ light weight lowers axial loads, reducing construction costs further. The construction industry significantly contributes to global energy consumption and emissions, necessitating sustainable alternatives to conventional practices. In this context, this study introduces a novel composite structural typology that combines reinforced concrete (RC) columns with transversely hybrid variable section (THVS) steel girders as beam-type elements. The proposed building frame leverages the high horizontal stiffness of RC columns and the reduced weight of steel girders to lower material consumption. The THVS variant has proven to be one of the most sustainable steel I-girder configurations. Two arrangements are analyzed: one with fixed beam-column connections and another with pinned joints. Structural design optimization problems are formulated, targeting three objectives: economic cost, CO 2 (e) emissions, and embodied energy. These indicators are evaluated using a “cradle-to-site” approach. Results demonstrate that the fixed connection typology is optimal for buildings with shorter spans (4 m), achieving reductions in economic cost (6 %), emissions (16 %), and embodied energy (11 %) compared to traditional RC structures. The pinned variant is more suitable for longer span buildings (8 m), resulting in economic gains of around 5 % and a 6 % reduction in emissions despite higher energy requirements. Optimal THVS configurations indeed employ higher-grade steels in flanges than in the web, with tapered geometries varying by span length and connection type. The study also highlights that the THVS girders’ lighter weight significantly lowers axial loads on columns and foundations, further reducing construction costs and environmental impacts of the structural assembly. These findings underscore the potential of composite designs to enhance sustainability in building construction.
Comparative Life Cycle Assessment of Warehouse Construction Systems Under Distinct End-of-Life Scenarios
Paulo Cezar Vitorio Junior, Víctor Yepes, Fabio Onetta, Moacir Kripka
Buildings, 2025
There is an increasing demand to replace traditional construction techniques with more sustainable systems that can reduce environmental impacts. Emissions are typically assessed only in carbon dioxide and embodied energy terms, yet these metrics alone cannot fully capture the overall impact generated. This study provides a comparative Life Cycle Assessment (LCA) of three steel warehouse projects with varying cladding systems: steel walls (SW), steel-clay brick walls (SClaW), and steel-concrete block walls (SConW). Life Cycle Assessment (LCA) methodology was used to assess the environmental impact of materials used during the whole life cycle. The study used the software program SimaPro (System for Integrated Environmental Assessment of Products) version 9.6.0.1, with data extracted from the international Ecoinvent database. ReCiPe Midpoint approach were adopted to assess potential impacts. The results indicate that the SW project under end-of-life Scenario 2—waste recycling—exhibited the lowest impacts across most categories, followed by the SConW and SClaW projects. The findings emphasize the environmental benefits of utilizing steel cladding systems over brick or concrete masonry and considering recycling as the end of life of the materials. Additionally, the study provides insights into the significance of material choices in minimizing environmental impact on human health, resource availability, and ecosystems.
Metamodel-assisted design optimization of robust-to-progressive-collapse RC frame buildings considering the impact of floor slabs, infill walls, and SSI implementation
Iván Negrin, Moacir Kripka, Víctor Yepes
Engineering Structures, 2025
Designing for safety and sustainability: Optimization of fire-exposed steelconcrete composite footbridges
Fernando L. Tres Junior, Guilherme F. de Medeiros, Moacir Kripka, V. Yepes
Structural Engineering and Mechanics, 2025
Optimization of CO2 emissions of composite alveolar beams considering manufacturing constraints
Elcio Cassimiro Alves, Moacir Kripka, Gabrieli Fontes Silva, Adenilcia Fernanda Grobério Calenzani
Rem International Engineering Journal, 2025
Practical Application of LCA to Optimize Environmental Impacts of Steel–concrete Footbridges
Fernando Luiz Tres Junior, Víctor Yepes, Guilherme Fleith de Medeiros, Moacir Kripka
World Sustainability Series, 2025
Optimal sustainable design of steel-concrete composite footbridges considering different pedestrian comfort levels
Steel and Composite Structures, 2024
CO2 emission optimization of composite floor systems with cellular beams via metaheuristics algorithms
Structural Engineering and Mechanics, 2024
Evaluation of CO2 emissions in RC structures considering local and global databases
Jair F. Santoro, Moacir Kripka
Innovative Infrastructure Solutions, 2024
Optimized Transverse-Longitudinal Hybrid Construction for Sustainable Design of Welded Steel Plate Girders
Iván Negrin, Moacir Kripka, Víctor Yepes
Advances in Civil Engineering, 2024
Towards sustainable reinforced concrete beams: multi-objective optimization for cost, CO2 emission, and crack prevention
Nathanael Risson dos Santos, Elcio Cassimiro Alves, Moacir Kripka
Asian Journal of Civil Engineering, 2024
Design optimization of welded steel plate girders configured as a hybrid structure
Iván Negrin, Moacir Kripka, Víctor Yepes
Journal of Constructional Steel Research, 2023
Multi-criteria optimization for sustainability-based design of reinforced concrete frame buildings
Iván Negrin, Moacir Kripka, Víctor Yepes
Journal of Cleaner Production, 2023
Metamodel-assisted meta-heuristic design optimization of reinforced concrete frame structures considering soil-structure interaction
Iván Negrin, Moacir Kripka, Víctor Yepes
Engineering Structures, 2023
Metamodel-assisted design optimization in the field of structural engineering: A literature review
Iván Negrin, Moacir Kripka, Víctor Yepes
Structures, 2023
Multi-Objective Optimization Applied to the Design of Sustainable Pedestrian Bridges
Fernando Luiz Tres Junior, Víctor Yepes, Guilherme Fleith de Medeiros, Moacir Kripka
International Journal of Environmental Research and Public Health, 2023
Simulated squirrel search algorithm: A hybrid metaheuristic method and its application to steel space truss optimization
Steel and Composite Structures, 2022
Comparison of Brazilian Social Interest Housing Projects Considering Sustainability
Paulo Cezar Vitorio Junior, Víctor Yepes, Moacir Kripka
International Journal of Environmental Research and Public Health, 2022
Optimized sizing of reinforced concrete structural elements considering the effect of carbonation
Jeferson Junior Alievi, Jair Frederico Santoro, Moacir Kripka
Revista Ibracon De Estruturas E Materiais, 2022
Selection of production mix in the agricultural machinery industry considering sustainability in decision making
Anderson Hoose, Víctor Yepes, Moacir Kripka
Sustainability Switzerland, 2021
Life cycle assessment of bridges using bayesian networks and fuzzy mathematics
Zhi-Wu Zhou, Julián Alcalá, Moacir Kripka, Víctor Yepes
Applied Sciences Switzerland, 2021
Study of alternatives for the design of sustainable low-income housing in Brazil
Pollyanna Fernandes Bianchi, Víctor Yepes, Paulo Cezar Vitorio, Moacir Kripka
Sustainability Switzerland, 2021
Correlational investigation of manufacturing technology and environmental impact in an agricultural machinery industry
H Akinaga, A Butov, N Castro, G De Camargo Barros, A Almeida, et al.
Global Nest Journal, 2021
Proposal of sustainability indicators for the design of small-span bridges
Cleovir José Milani, Víctor Yepes, Moacir Kripka
International Journal of Environmental Research and Public Health, 2020
Optimization of steel-concrete composite beams considering cost and environmental impact
Andréia Fátima Tormen, Zacarias Martin Chamberlain Pravia, Fernando Busato Ramires, Moacir Kripka
Steel and Composite Structures, 2020
Evaluation of short span bridge projects with a focus on sustainability
Cleovir José Milani, Moacir Kripka
Structure and Infrastructure Engineering, 2020
Fair wage potential as a tool for social assessment in building projects
Paulo Cezar Vitorio Junior, Moacir Kripka
Engineering Construction and Architectural Management, 2020
Minimizing environmental impact from optimized sizing of reinforced concrete elements
Jair Frederico Santoro, Moacir Kripka
Computers and Concrete, 2020
Experimental and analytical study of vibration parameters in waffle concrete slabs
Fernanda Scussiato Lago, Moacir Kripka, Osama (Sam) Salem, Zacarias M. Chamberlain Pravia
Engineering Structures, 2019
Optimization of reinforced concrete building frames with automated grouping of columns
Juliana Triches Boscardin, Victor Yepes, Moacir Kripka
Automation in Construction, 2019
Selection of sustainable short-span bridge design in Brazil
Moacir Kripka, Victor Yepes, Cleovir José Milani
Sustainability Switzerland, 2019
Artificial Intelligence Applications in Civil Engineering
Tayfun Dede, Murat Kankal, Ali Reza Vosoughi, Maksym Grzywiński, Moacir Kripka
Advances in Civil Engineering, 2019
Advanced Optimization Techniques and Their Applications in Civil Engineering
Tayfun Dede, Moacir Kripka, Vedat Toğan, Victor Yepes, Ravipudi V. Rao
Advances in Civil Engineering, 2018
Modified harmony search and its application to cost minimization of RC columns
Guilherme F. Medeiros, Moacir Kripka
Advances in Computational Design, 2017
Simultaneous geometry and cross-section optimization of aluminum trusses
Moacir Kripka, Zacarias Chamberlain Pravia, Guilherme Fleith Medeiros, Maiga Marques Dias
Multidiscipline Modeling in Materials and Structures, 2016
Use of optimization for automatic grouping of beam cross-section dimensions in reinforced concrete building structures
Moacir Kripka, Guilherme F. Medeiros, Afonso C.C. Lemonge
Engineering Structures, 2015
Optimization of reinforced concrete columns according to different environmental impact assessment parameters
Guilherme Fleith de Medeiros, Moacir Kripka
Engineering Structures, 2014
Minimizing the environmental impact of R-C structural elements
M Kripka, G Medeiros, J Fraga, P Marosin
Engineering Optimization IV Proceedings of the 4th International Conference on Engineering Optimization Engopt 2014, 2014
Cold-formed steel channel columns optimization with simulated annealing method
Moacir Kripka, Zacarias Martin Chamberlain Pravia
Structural Engineering and Mechanics, 2013
Optimum support positions in bridges
Universidade de Passo Fundo, Passo Fundo, RS, Brasil, Moacir Kripka, Luttgardes de Oliveira Neto, Universidade Estadual Paulista “Julio de Mesquita Filho”, Câmpus de Bauru, SP, Brasil, Rosana Maria Luvezute Kripka, Universidade de Passo Fundo, Passo Fundo, RS, Brasil
Ciencia Y Engenharia Science and Engineering Journal, 2013
Structural optimization and proposition of pre-sizing parameters for beams in reinforced concrete buildings
Guilherme Fleith de Medeiros, Moacir Kripka
Computers and Concrete, 2013
Cross-sectional optimization of reinforced concrete columns considering both economical and environmental costs
Moacir Kripka, Guilherme Fleith de Medeiros
Applied Mechanics and Materials, 2012
Cross section optimization using simulated annealing of cold-formed steel channel columns
Structural Stability Research Council Annual Stability Conference 2012, 2012
Optimum design of reinforced concrete columns subjected to uniaxial flexural compression
R. Bordignon, M. Kripka
Computers and Concrete, 2012
Parameters for the optimal section design of steel cold-formed channel in bending
Structural Stability Research Council Annual Stability Conference 2011 ASC, 2011
Numerical and experimental optimization of cold formed steel c-sections under compression
Zacarias M. Chamberlain Pravia, Moacir Kripka
Revista Escola De Minas, 2008
Workload distribution in institutions of higher education: A formularization for the maximization of the human resources utilization
Ciencia Y Engenharia Science and Engineering Journal, 2005
Discrete optimization of trusses by simulated annealing
M. Kripka
Journal of the Brazilian Society of Mechanical Sciences and Engineering, 2004
Optimum support positions in building grillages
International Conference on Computer Aided Optimum Design of Structures OPTI Proceedings, 2001
Optimization of continuous beams submitted to different boundary conditions
Ciencia and Engenharia Science and Engineering Journal, 1999

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