Search in Publications

Found 6674 publications

NVH characterization of a ladder-like welded structure using finite element analysis and experimental method

Daniel Feszty Balázs Vehovszky Attila Schweighardt

Publication Name: Advances in Acoustics Noise and Vibration 2021 Proceedings of the 27th International Congress on Sound and Vibration Icsv 2021

Publication Date: 2021-01-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

In vehicle industry, considering a chassis, the evaluation of the experimental modal analysis is usually done up to 80 Hz, since the modal density is increasing with frequency. In addition, the deviation between the measurement and simulation is getting more significant at higher frequencies. The purpose of this study is to extend the usable test range and to improve the accuracy of the results both in case of measurement and FE (Finite Element) simulation. Present paper introduces the vibrational characterization of a ladder-like welded structure. This test case represents a simplified model of a vehicle's frame consisting of rod-like elements with high stiffness, connected to each other in welded junctions. Although such simulational and experimental modal analysis procedures are widely used in practice, results can significantly change according to the used method and the fine-tuning of parameters. For this reason, a further goal is to find the best measurement and simulation technique for the given structure. During the FE analysis different modelling solutions and element types were compared. In order to discover the effect of the manufacturing inaccuracies, the same measurements were performed on two distinct, but theoretically identical samples. The influence of the experimental setup (e.g. excitation and fixing method) and settings were investigated as well. Finally, FE simulation and experimental results are compared using Frequency Response Functions.

Open Access: Yes

DOI: DOI not available

Artificial intelligence and emerging technologies: Exploring opportunities through smart specialisation

No authors available

Publication Name: Handbook of Research on Artificial Intelligence, Innovation and Entrepreneurship

Publication Date: 2023-02-14

Volume:

Issue:

Page Range: 237-253

Description:

Open Access: No

DOI: DOI not available

Building Diagnostics Options for Existing Buildings – Innovative Methods

None Bukovics Kitti Ajtayné Károlyfi Dóra Szalai Zsolt Szűrös Rita Rebeka Ördög

Publication Name: Chemical Engineering Transactions

Publication Date: 2024-01-01

Volume: 114

Issue: Unknown

Page Range: 793-798

Description:

The increasing number of buildings, due to erosion and extraordinary effects, has increasingly made technological advancements focused on innovative methods possible. This has become more prominent alongside traditional practices such as visual inspection and destructive building diagnostic methods. Thanks to the continuous development of tools, technologies and methodologies, the accurate and detailed digital mapping of buildings (including all their aspects) is available. Among these solutions, the laser scanner point cloud is the most popular due to its high level of detail. The newly emerging and now widespread survey procedures based on laser, photogrammetric remote sensing reflect a real-time, current state of the buildings, which maximizes the accuracy of the Building Information Model (BIM) - Historic Building Information Model (HBIM) completed in the later phases and helps detect structural or surface defects. This study presents the analyzing techniques of point clouds to diagnose buildings, assess their condition, identify errors, and develop sustainability strategies. It also explores areas that require further research and development to enhance the effectiveness of these methods. In the first phase of the paper, the currently used point cloud generation technologies (e.g.: laser scanning, photogrammetry, light detection and ranging (LiDAR)) will be presented with their advantages and disadvantages. The research methodology was conducted using the VOSviewer software to visually analyze bibliometric networks from a dataset of scientific publications, focusing on trends in structural health monitoring and highlighting key areas such as damage detection, computer vision, and AI-based techniques. In the second phase of the study, the possibilities of the analysis of point clouds and image processing-based survey options for structural diagnostic purposes will be explained and presented. The evaluation of the three damage detection methodologies (Geometrical features, Color and intensity information, Combined Method) highlights their complexity, technological requirements, cost, practical applicability, and accuracy. During the analysis, the goal is to map and systematize innovative methods supported by digital tools for diagnostic tasks in existing buildings.

Open Access: Yes

DOI: 10.3303/CET24114133

Computer tomography based reconstruction of metal matrix syntactic foams

I. Zsoldos Sz Papp István Kozma G. Dorogi

Publication Name: Periodica Polytechnica Mechanical Engineering

Publication Date: 2014-01-01

Volume: 58

Issue: 2

Page Range: 87-91

Description:

In order to create 3D (three-dimensional) models for finite element calculations it is necessary to reconstruct the structure of metal foam composites reinforced by hollow ceramic spheres. A new algorithm was developed for this reconstruction work. This algorithm is based on the investigation of sphericity of the shapes found on CT (computer tomograph) layer records. Using this algorithm a 3D CAD (computer aided design) model of acceptable precision can be constructed.

Open Access: Yes

DOI: 10.3311/PPme.7337

Seismic Performance and Sustainability of Reinforced Concrete Buildings: a Comprehensive Assessment

Nurullah Bektaş Samuel Alexandro Silitonga

Publication Name: Chemical Engineering Transactions

Publication Date: 2024-01-01

Volume: 114

Issue: Unknown

Page Range: 781-786

Description:

Recent earthquakes such as the 2023 Türkiye-Syria, Morocco, and Afghanistan, 2015 Gorkha Nepal, and 2009 Indonesia earthquakes have demonstrated the vulnerability of existing building stock. Throughout Europe, many existing buildings were constructed considering low or moderate standards or without considering them. This study investigates the seismic performance of reinforced concrete (RC) buildings, exemplified as a six-story RC dormitory building, focusing on various support and foundation conditions, soil characteristics, and site seismicity scenarios representing the seismicity of Europe. The research aims to assess the potential effects of exceeding anticipated site seismic intensities, potentially leading to safer communities and infrastructure in the face of impending earthquakes. Robot Structural Analysis Professional software is used for structural analysis and design throughout soil-structure interactions and site seismicity considerations. Moreover, this study investigates the environmental implications of RC buildings, which represent the future building inventory in Europe. It examines the varying material usage required to design structures compliant with Eurocode standards through a life cycle analysis. The methodology employed in this investigation aligns with the core principles of practical design encompassing economic and environmental sustainability. The study's key findings indicate that increasing member size can enhance performance at lower intensities, but this may not be a sufficient strategy at higher intensities, where shear walls may be necessary in high seismic zones. Sustainable design necessitates a balance between material use, performance, and environmental impact.

Open Access: Yes

DOI: 10.3303/CET24114131

CHALLENGES AND OPPORTUNITIES IN THE ENERGETIC MODERNIZATION OF HISTORIC RESIDENTIAL BUILDINGS IN BUDAPEST DOWNTOWN

T. Horváth Heléna Szecskő

Publication Name: Iet Conference Proceedings

Publication Date: 2024-01-01

Volume: 2024

Issue: 8

Page Range: 82-88

Description:

A significant part of the buildings in the downtown of Budapest were built at the turn of the century, the condition of the load-bearing structures is usually adequate, but the secondary structures and mechanical systems are outdated, and from an energy point of view the building stock is mostly outdated and inefficient. In case of historical buildings, energy renovation is not a simple, self-evident process, as it requires a differentiated approach and striving for the optimum. This study provides an overview of the different building structures, analyses the possibilities of energy renovation, and formulates a proposal on the extent and method of interventions. Using the example of a case study, it quantifies the amount of the energy improvement that can be achieved by implementing different renovation scenarios. Energy calculations carried out on the selected sample building demonstrated that deep renovation can result in significant energy and CO2 savings. It has also demonstrated that, in addition to the comprehensive whole building envelope upgrades, the modernization of the mechanical systems is also required in order to achieve significant improvements in the energy performance of the building.

Open Access: Yes

DOI: 10.1049/icp.2024.2686

Characterisation of hardening performance of quenchants by integrated numerical method

Imre Felde Tamás Réti

Publication Name: International Heat Treatment and Surface Engineering

Publication Date: 2008-06-01

Volume: 2

Issue: 2

Page Range: 55-59

Description:

An integrated numerical technique for evaluation of hardening performance of cooling media applied for steel quenching is outlined. The newly developed method is based on the specific processing of measured time-temperature samples performed as a result of cooling curve tests. The heat transfer coefficient as a function of surface temperature characterises the heat transfer during cooling and is calculated using an iterative inverse algorithm. The heat transfer coefficient is used for calculation of the microstructural constituents and the hardness profile of cylindrical samples of arbitrary diameter. The hardening performance of media is evaluated by the estimated hardness of specimens obtained by heat treatment. © 2008 IHTSE Partnership.

Open Access: Yes

DOI: 10.1179/174951508X318404

Understanding intentions towards seeking university-business partnerships – analysing four european cases

Zsolt Kohus Katalin Czakó Zoltán Baracskai

Publication Name: Journal of International Studies

Publication Date: 2021-01-01

Volume: 14

Issue: 2

Page Range: 228-244

Description:

It is an important economic and social issue for universities to provide value for their communities by seeking and maintaining partnerships with local firms. This paper analyses institutions of different national economies. It systematises the differences and similarities in the communication of universities aiming to partnering. To this end, we present four European cases from France, Germany, Hungary and Poland. The methodology lies in its grounded theory approach to a continuous multi-case analysis. Our hypotheses are as follows: There are role differences of universities in the observed cases (H1). There are different understandings behind fruitful university-business partnerships (H2). The rate of diversification in local industries effects the presence and types of university services and business partnering activity (H3). Data hubs were extracted from institutional communications and integrated with local economic data input. The novel approach of applying the grounded theory supports complex observation. Notions of fruitful partnerships are institution-specific, but we identify two opposite perspectives of strategies to run efficient university-business partnering. The structure of the local industrial environment, research output and university-business interactions have definable mutual effects.

Open Access: Yes

DOI: 10.14254/2071-8330.2021/14-2/15

Investigation of confinement effect by using the multi-level shear box test

J. Klompmaker Ferenc Horvát

Publication Name: 10th International Conference on Geosynthetics Icg 2014

Publication Date: 2014-01-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

The stabilisation and reinforcement of crushed stone aggregate in infrastructural applications using geogrid reinforcement is based on the phenomenon called the "interlocking effect". Through shear interaction of the aggregate with the geogrid, the aggregate is laterally restrained and tensile forces are transmitted from the aggregate to the geogrid. This interaction helps reducing lateral movement of the aggregate and optimises road/track performance. It is well known that this strengthening effect depends on several influencing factors. It is still difficult to quantify the true reinforcement efficiency with regard to the limit of the lateral restraint effect (or confining resistance) over the depth of the aggregate layer being placed on top of the geogrid. To be able to quantify the confining resistance efficiency of geogrids over the depth of the installed aggregate layer a laboratory test was developed (Multi-level shear box test) which allows measuring the shear resistance as a function of the distance from the geogrid layer (in vertical direction). This paper will describe the methodology of the so called "Multi-level shear box test" as well as the results of the confinement efficiency of different type geogrids in combination with railway ballast.

Open Access: Yes

DOI: DOI not available