Daniel Gosztola

57973826400

Publications - 10

Script-Based Material and Geometrical Modeling of Steel–Concrete Composite Connections for Comprehensive Analysis Under Varied Configurations

J. Szép M. Movahedi Rad Daniel Gosztola Péter Grubits

Publication Name: Applied Sciences Switzerland

Publication Date: 2025-03-01

Volume: 15

Issue: 6

Page Range: Unknown

Description:

The behavior of steel–concrete composite structures is significantly influenced by the efficiency of the shear connections that link the two materials. This research examines the performance of stud shear connectors, with an emphasis on analyzing the effect of different geometric design parameters. A computational model was created utilizing Python 3.13 to enable thorough digital monitoring of the influence of these parameters on the structural performance of composite connections. Developed within the ABAQUS framework, the model integrates geometric nonlinearity and the Concrete Damage Plasticity (CDP) approach to achieve detailed simulation of structural behavior. Essential design aspects, including stud diameter, stud height, head dimensions, and spacing in both longitudinal and transverse directions, were analyzed. The Python-based parametric model allows for easy modification of design parameters, ensuring efficiency and minimizing modeling errors. The significance of stud diameter changes was analyzed in accordance with Eurocode standards and previous studies. It was found that stud length has a reduced effect on structural performance, particularly when considering the concrete properties used in bridge construction, where compressive failure of the concrete zone is more critical at lower concrete strengths. Additional factors, such as stud head dimensions, were investigated but were found to have minimal effect on the behavior of steel–concrete composite connections. Longitudinal stud spacing emerged as a critical factor influencing structural performance, with optimal results achieved at a spacing of 13d. Spacings of 2d, 3d, and 4d demonstrated overlapping effects, leading to significant performance reductions, as indicated by comparisons of ultimate load and force–displacement responses. For transverse spacing, closer stud arrangements proved effective in reducing the likelihood of slip at the steel–concrete interface, enhancing composite action, and lowering stress concentrations. Additionally, reducing the transverse distance between studs allowed for the use of more shear connectors, increasing redundancy and enhancing performance, especially with grouped-stud connectors (GSCs).

Open Access: Yes

DOI: 10.3390/app15063095

Plastic Limited Numerical Modelling on Contact Friction Effects of Steel–Concrete Connection for Composite Bridges

Oveys Ghodousian J. Szép Marco Domaneschi M. Movahedi Rad Raffaele Cucuzza Daniel Gosztola

Publication Name: Buildings

Publication Date: 2024-09-01

Volume: 14

Issue: 9

Page Range: Unknown

Description:

This research employs plastic limit analysis to examine load combinations, contact interactions, and friction effects on steel–concrete connections. A nonlinear finite element model was developed using ABAQUS 2021, incorporating the concrete damage plasticity model and contact friction interactions. The model’s validity was confirmed through laboratory experiments. Results indicate that contact elements and friction between the top flange, concrete slab, and studs significantly influence structural behavior. Unlike conventional push-out tests, real deck–slab connections exhibit different load-displacement responses due to the self-weight and additional loads, such as vehicular traffic. Under horizontal loading, extensive failures with large deformations along the studs occur, while vertically compressive loads lead to failures around the connections.

Open Access: Yes

DOI: 10.3390/buildings14092898

Effect of the Particle Size Distribution of the Ballast on the Lateral Resistance of Continuously Welded Rail Tracks

Szabolcs Fischer Morteza Esmaeili M. Movahedi Rad Jafar Chalabii Daniel Gosztola

Publication Name: Infrastructures

Publication Date: 2024-08-01

Volume: 9

Issue: 8

Page Range: Unknown

Description:

While the effect of ballast degradation on lateral resistance is noteworthy, limited research has delved into the specific aspect of ballast breakage in this context. This study is dedicated to assessing the influence of breakage on sleeper lateral resistance. For simplicity, it is assumed that ballast breakage has already occurred. Accordingly, nine granularity variations finer than No. 24 were chosen for simulation, with No. 24 as the assumed initial particle size distribution. Initially, a DEM model was validated for this purpose using experimental outcomes. Subsequently, employing this model, the lateral resistance of different particle size distributions was examined for a 3.5 mm displacement. The track was replaced by a reinforced concrete sleeper in the models, and no rails or rail fasteners were considered. The sleeper had a simplified model with clumps, the type of which was the so-called B70 and was applied in Western Europe. The sleeper was taken into consideration as a rigid body. The crushed stone ballast was considered as spherical grains with the addition that they were divided into fractions (sieves) in weight proportions (based on the particle distribution curve) and randomly generated in the 3D model. The complete 3D model was a 4.84 × 0.6 × 0.57 m trapezoidal prism with the sleeper at the longitudinal axis centered and at the top of the model. Compaction was performed with gravity and slope walls, with the latter being deleted before running the simulation. During the simulation, the sleeper was moved horizontally parallel to its longitudinal axis and laterally up to 3.5 mm in static load in the compacted ballast. The study successfully established a relationship between lateral resistance and ballast breakage. The current study’s findings indicate that lateral resistance decreases as ballast breakage increases. Moreover, it was observed that the rate of lateral resistance decrease becomes zero when the ballast breakage index reaches 0.6.

Open Access: Yes

DOI: 10.3390/infrastructures9080129

Advanced Numerical Simulation and Modeling of Multi-Pass Welding Processes: Detailed Analysis of Temperature Distribution in Structural Elements

J. Szép M. Movahedi Rad Daniel Gosztola Péter Grubits

Publication Name: Chemical Engineering Transactions

Publication Date: 2024-01-01

Volume: 114

Issue: Unknown

Page Range: 823-828

Description:

The growing importance of numerical simulations in the welding industry stems from their ability to enhance structural performance and sustainability by ensuring optimal manufacturing conditions. The use of the finite element method (FEM) allows for detailed and precise calculations of the mechanical and material changes caused by the welding process. Acquiring knowledge of these parameters not only serves to augment the quality of the manufacturing process but also yields consequential benefits, such as reducing adverse effects. Consequently, the enhancement of structural performance and prolonged lifespan becomes achievable, aligning with overarching sustainability goals. To achieve this goal, this paper utilizes numerical simulations of welding processes based on experimental tests, with a specific focus on analyzing temperatures generated within the structures. In the finite element analysis (FEA), a total of 12 welding cycles were systematically modeled to align with experimental conditions, incorporating cooling intervals, preheating considerations, and the relevant section of the connecting concrete structure with studs. The outcomes of this research exemplify the potential of numerical simulation in the welding industry, demonstrating a diverse range of results achieved through FEA to enhance the quality of structures within the context of sustainability.

Open Access: Yes

DOI: 10.3303/CET24114138

Experimental results of sliding and welding tests in a novel construction method for steel-concrete composite bridges

J. Szép Daniel Gosztola

Publication Name: Fib Symposium

Publication Date: 2024-01-01

Volume: Unknown

Issue: Unknown

Page Range: 923-930

Description:

The primary objective of this study is to introduce a novel construction method used for steel-concrete composite bridges. Throughout the article, domestic and international solutions and practices will be provided for various girder-prefabricated deck slab connections, as well as construction methods for steel-concrete composite bridges. The new bridge construction technology involves the construction of a prefabricated deck slab on-site, which is moved into its final position on the main girders. During prefabrication, a stud plate is positioned within the formwork, facilitating the sliding of the deck slab elements onto the girder. The upper flange and stud plate are joined by welding following the sliding of the deck parts. The key challenge for this technology is achieving a sufficiently low friction coefficient between the stud plate and the flange using a suitable material. However, it is imperative to identify a material that can be compatible with the welded connection. Laboratory experiments were carried out to investigate the effect of materials on the friction coefficients between steel plates and the welding of the connection. The ideal material has been identified through experiments to lower the coefficient of friction to 4-8% while the welded joint can be achieved.

Open Access: Yes

DOI: DOI not available

The Effect of the Friction Coefficient Between the Steel-Concrete Connection on the Horizontal Load Capacity

J. Szép M. Movahedi Rad Daniel Gosztola

Publication Name: Advances in Transdisciplinary Engineering

Publication Date: 2024-01-01

Volume: 59

Issue: Unknown

Page Range: 143-150

Description:

This article presents experimental tests and numerical modeling of steelcomposite connections. The study considers the interaction and friction coefficient between the steel structure and concrete, as well as between the steel studs and concrete. The numerical model underwent validation through an iterative process, considering various friction coefficients. The friction coefficient between the structure and the concrete exerted the most significant impact on the load capacity. a new finite element model has been developed, with various friction coefficients between steel structure and concrete, and in this model, the concrete was also subjected to different vertical compression loads. A total of 25 numerical tests have been conducted, using various configurations of vertical load and friction coefficient parameters. It was observed that higher friction coefficients increase the impact of vertical forces on the horizontal load capacity. The friction coefficient can be increased through technological interventions, such as surface roughening techniques or the introduction of intermediate materials designed to elevate it.

Open Access: Yes

DOI: 10.3233/ATDE240538

Numerical Modeling of Multi-Pass Arc Welding Processes: Integration with Experimental Validation for Distortion analysis and Characterization

J. Szép Marco Domaneschi M. Movahedi Rad Raffaele Cucuzza Daniel Gosztola Péter Grubits

Publication Name: Advances in Transdisciplinary Engineering

Publication Date: 2024-01-01

Volume: 59

Issue: Unknown

Page Range: 248-254

Description:

The increasing significance of numerical simulations in the welding industry arises from their capacity to improve manufacturing conditions, ensuring greater effectiveness and precision. The utilization of the finite element method (FEM) enables comprehensive and focused calculations of mechanical and material structural alterations induced by the welding process. Acquiring knowledge of these parameters not only serves to augment the quality of the manufacturing process but also yields consequential benefits, such as reducing adverse effects like base plate distortion. Consequently, enhancing structural performance and prolonging lifespan becomes achievable, aligning with overarching sustainability goals. To accomplish this objective, this paper involves the numerical simulation of a welding process based on experimental tests, with a focus on investigating the deformations caused by the heat generated during welding as the primary parameter of interest. Advanced modeling techniques are employed to assess the results as part of a comprehensive thermo-mechanical analysis framework, examining and characterizing the impact of the temperature distribution. In the finite element analysis (FEA), a total of 12 welding cycles were systematically modeled to align with experimental conditions, incorporating cooling intervals and preheating considerations. The outcomes of this research exemplify the potential of numerical simulation in the welding industry, demonstrating a diverse range of results achieved through FEA to enhance the quality of structures.

Open Access: Yes

DOI: 10.3233/ATDE240552

Elasto-plastic analysis and optimal design of composite integral abutment bridge extended with limited residual plastic deformation

J. Szép M. Movahedi Rad Sarah Khaleel Ibrahim Dániel Harrach Daniel Gosztola Ferenc Papp

Publication Name: Scientific Reports

Publication Date: 2023-12-01

Volume: 13

Issue: 1

Page Range: Unknown

Description:

Due to the growing significance of structural theories concerning the composite structure analysed and designed plastically, this paper introduces a new optimisation method for controlling the plastic behaviour of a full-scale composite integral abutment bridge by employing complementary strain energy of residual forces that existed within the reinforcing rebars. Composite bridges are structures made of components such as steel and concrete, which are frequent and cost-effective building methods. Thus, various objective functions were used in this work when applying optimum elasto-plastic analysing and designing the composite integrated bridge structure that was tested experimentally in the laboratory. In contrast, the plastic deformations were constrained by restricting the complementary strain energy of the residual internal forces aiming to find the maximum applied load and the minimum number of steel bars used to reinforce the concrete column part of the structure. The numerical model employed in this paper was validated and calibrated using experimental results, which were considered inside ABAQUS to produce the validated numerical model, using concrete damage plasticity (CDP) constitutive model and concrete data from laboratory testing to solve the nonlinear programming code provided by the authors. This paper presents a novel optimization method using complementary strain energy to control the plastic behaviour of a full-scale composite integral abutment bridge, with the original contribution being the incorporation of residual forces within reinforcing rebars to limit plastic deformations. Following that, a parametric investigation of the various optimisation problems revealed how models performed variously under different complementary strain energy values, which influenced the general behaviour of the structure as it transitioned from elastic to elasto-plastic to plastic; also results showed how the complementary strain energy value is connected with the amount of damaged accrued in both concrete and steel.

Open Access: Yes

DOI: 10.1038/s41598-023-32787-y

Advanced Numerical Simulation and Modeling of Welding Processes: Stochastic representation of parameters for Improved Fabrication

J. Szép M. Movahedi Rad Muayad Habashneh Daniel Gosztola Péter Grubits

Publication Name: Chemical Engineering Transactions

Publication Date: 2023-01-01

Volume: 107

Issue: Unknown

Page Range: 619-624

Description:

Numerical simulations play a pivotal role in advancing fabrication processes and welding technologies, enabling the pursuit of sustainable practices. By employing the finite element method, crucial insights regarding welded specimens can be derived, encompassing deformed shapes, residual stresses, and even microstructural properties such as phase proportions and hardness. This study focuses on the modeling framework of welding processes, emphasizing the influence of various welding parameters on sustainable outcomes, including reduced environmental impact and enhanced resource efficiency. The investigation delves into the characterization of heat sources, accounting for temperature-dependent material properties and developing a comprehensive thermo-mechanical analysis. By incorporating sustainability considerations and utilizing our Finite Element (FE) model, we conducted further analysis to elucidate the stability behavior, aligning with sustainable objectives. By considering welding current, arc voltage, and welding speed as random variables with mean values and standard deviations, the study aims to identify a model that effectively accounts for the inherent randomness of the welding process. This research contributes to the growing body of knowledge on sustainable welding practices by merging numerical simulations, advanced modeling techniques, and sustainability principles. The outcomes of this study have the potential to inform industry stakeholders and decision-makers about the most effective strategies for achieving sustainable welding processes and minimizing the ecological footprint of the welding operations.

Open Access: Yes

DOI: 10.3303/CET23107104

PAVEMENT SENSING SYSTEMS: LITERATURE REVIEW

Richárd Nagy Mohammad Fahad Daniel Gosztola

Publication Name: Civil and Environmental Engineering

Publication Date: 2022-12-01

Volume: 18

Issue: 2

Page Range: 603-630

Description:

In situ monitoring of pavement health has been getting much attention due to the efficiency, reliability and accuracy of data. This review consists of various embedded as well as nondestructive sensing options that have been used to perform analysis on pavement health either by simply calculating horizontal and vertical strains under pavement layers or by crack detection models inside pavement structures by supplementing information from moisture, temperature and traffic related sensors. With optimum integration of such combination sensors, engineers can predict the optimum rehabilitation time of the pavements and reduce a huge amount of budget spent on infrastructure reconstruction.

Open Access: Yes

DOI: 10.2478/cee-2022-0057