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Publications - 6278

Structural topology optimization for plastic-limit behavior of I-beams, considering various beam-column connections

Marco Domaneschi Peyman Aela Majid Movahedi Rad Raffaele Cucuzza Muayad Habashneh Péter Grubits

Publication Name: Mechanics Based Design of Structures and Machines

Publication Date: 2025-01-01

Volume: 53

Issue: 4

Page Range: 2719-2743

Description:

This work proposes topology optimization for steel I-beams, including consideration of bolted beam-column connections with geometric and material nonlinear analysis. The aim is to assess and compare the topological configurations influenced by different connections, examining their stress distribution and rotational stiffness to illustrate the potential of structural optimization. The bi-directional evolutionary structural optimization (BESO) approach is implemented. Furthermore, several bolted steel beam-column configurations were validated based on experimental tests. Subsequently, a series of finite element models were developed, contributing to a comprehensive understanding of the plastic-limit behavior of I-beams under different loading conditions. The proposed method could potentially use a lesser quantity of material while maintaining the same level of structural performance. The results indicate that the implementation of structural topology optimization on I-beams while considering various beam-column connections, yields structural performance similar to that of solid web configurations, achieved through material reduction.

Open Access: Yes

DOI: 10.1080/15397734.2024.2412757

Simulation of phase transformations in steel parts produced by laser powder deposition

Lino Costa Augusto Moita De Deus Imre Felde R. Colaço Tamás Réti R. Vilar

Publication Name: Materials Science Forum

Publication Date: 2005-01-01

Volume: 473-474

Issue: Unknown

Page Range: 315-320

Description:

Multilayer laser powder deposition is being used for the rapid manufacturing of fully dense near net shape components in a wide variety of materials. In this process parts are built by overlapping consecutive layers of a laser melted material. As a result of this overlapping, the material in each layer will undergo successive thermal cycles as new layers are deposited. Despite their short duration, these thermal cycles can activate solid-state transformations that lead to progressive modification of the microstructure and properties of the material. Since the thermal history of the material in the deposited part will differ from point to point, the part will present a complex and heterogeneous microstructure, and properties that differ from point to point. Given that the microstructure and property distribution in steel parts produced by laser powder deposition can only be predicted by modelling, a three-dimensional thermo-kinetic finite element model of laser powder deposition of tool steels was developed, In the present work this model was applied to the study of the influence of substrate size on the microstructure and properties of a six-layer wall of AISI 420 tool steel. The results show that the temperature field depends significantly on the size of the substrate, leading to distinct microstructures and properties in the final part. © 2005 Trans Tech Publications, Switzerland.

Open Access: Yes

DOI: 10.4028/0-87849-957-1.315

Logistic conception for real-time based info-communication system applied in selective waste gathering

István Lakatos Ádám Titrik Tamás Péter

Publication Name: 2017 IEEE 14th International Scientific Conference on Informatics Informatics 2017 Proceedings

Publication Date: 2017-03-27

Volume: 2018-January

Issue: Unknown

Page Range: 203-209

Description:

Decreasing of available raw materials, fossil energy source and new approach made recycling necessary and inevitable. For recycling selective waste areas have been placed, where inhabitants can drop their waste for free. Waste containers have different saturation time, while gathering process is predefined, therefore independently whether it is needed or not they will be emptied. Further problem is that there is no optimization on the way to the container, which results in serious environmental load (noise and air pollution). This study deals with high level route optimization to minimize environmental load concerning noise and air pollution and by the application of real-time communication the appropriate containers are only going to be emptied.

Open Access: Yes

DOI: 10.1109/INFORMATICS.2017.8327247

Plastic-limit probabilistic structural topology optimization of steel beams

Majid Movahedi Rad Muayad Habashneh

Publication Name: Applied Mathematical Modelling

Publication Date: 2024-04-01

Volume: 128

Issue: Unknown

Page Range: 347-369

Description:

This work presents a novel geometrically nonlinear analysis with imperfections reliability-based topology optimization (RBTO) approach, considering the volume fraction and geometric imperfections as random variables due to their crucial connections to the manufacturability of web openings in steel I-beams. The objective is achieved by controlling the plastic behavior through limit analysis, which imposes a limit on the plastic ultimate load multipliers. The suggested method is developed by imposing constraints related to the available material volume. The bi-directional evolutionary structural optimization (BESO) method is utilized to fulfill the objectives of this paper. The adequacy of the proposed technique is demonstrated by comparing the results of the algorithm with benchmark steel beams that have conventional web openings. Based on the numerical examples, it appears that the selected technique has the potential to increase the load capacity of steel beams while utilizing the same quantity of material within the design domain. Moreover, the improved beams also exhibit better performance in terms of stress levels. The results of this research suggest that the proposed technique enhances the load capacity of steel beams while maintaining the same quantity of material and improving their performance in terms of stress levels.

Open Access: Yes

DOI: 10.1016/j.apm.2024.01.029

Categories of various plant biostimulants - Mode of application and shelf-life

Heino B. Papenfus Shubhpriya Gupta Vince Ördög Karel Doležal Jeffrey Norrie Wendy A. Stirk Alan T. Critchley Johannes van Staden James F. White Manoj G. Kulkarni

Publication Name: Biostimulants for Crops from Seed Germination to Plant Development A Practical Approach

Publication Date: 2021-01-01

Volume: Unknown

Issue: Unknown

Page Range: 1-60

Description:

A plant biostimulant is any substance or microorganism which can be applied to plants to enhance seed germination and plant growth development along with its nutritional efficiency. Plant biostimulants collectively influence: plant growth development, pollen tube development, flower and fruit set, plant pigments, shoot and root development, nutritional efficiency, yield and shelf-life of crops, rhizospheric and soil microorganisms, general soil health and plant-environment interactions. Biostimulants are derived from natural origins and can help reduce the use of chemical products and also mitigate the negative impacts of harmful chemicals in the environment. This chapter focuses on their modes of application and effects on crops and horticultural plants. It also emphasizes impacts on the shelf-life and efficiencies of commercial biostimulants, as compared to synthetic chemical products and highlights the opportunities and challenges of their market expansion.

Open Access: Yes

DOI: 10.1016/B978-0-12-823048-0.00018-6

Constrained ordered weighted averaging aggregation with multiple comonotone constraints

Lucian Coroianu Marek Gagolewski Robert Fuller Simon James

Publication Name: Fuzzy Sets and Systems

Publication Date: 2020-09-15

Volume: 395

Issue: Unknown

Page Range: 21-39

Description:

The constrained ordered weighted averaging (OWA) aggregation problem arises when we aim to maximize or minimize a convex combination of order statistics under linear inequality constraints that act on the variables with respect to their original sources. The standalone approach to optimizing the OWA under constraints is to consider all permutations of the inputs, which becomes quickly infeasible when there are more than a few variables, however in certain cases we can take advantage of the relationships amongst the constraints and the corresponding solution structures. For example, we can consider a land-use allocation satisfaction problem with an auxiliary aim of balancing land-types, whereby the response curves for each species are non-decreasing with respect to the land-types. This results in comonotone constraints, which allow us to drastically reduce the complexity of the problem. In this paper, we show that if we have an arbitrary number of constraints that are comonotone (i.e., they share the same ordering permutation of the coefficients), then the optimal solution occurs for decreasing components of the solution. After investigating the form of the solution in some special cases and providing theoretical results that shed light on the form of the solution, we detail practical approaches to solving and give real-world examples.

Open Access: Yes

DOI: 10.1016/j.fss.2019.09.006

SZTAKI @ ImageCLEFmed 2020 Tuberculosis Task

Bálint Daróczy Bence Lestyan András Benczúr

Publication Name: Ceur Workshop Proceedings

Publication Date: 2020-01-01

Volume: 2696

Issue: Unknown

Page Range: Unknown

Description:

In this paper we describe our submission to the ImageCLEFmed 2020 Tuberculosis task and discuss additional results on the training set with various neural networks. After some centralization and normalization we independently categorized the 2D slices with convolutional neural networks (traditional and residual feed-forward networks) and we aggregated the individual predictions based on the positions of the lung and the slices. Our additional experiments with various aggregation methods indicate that individual slices do not necessary contain enough information about such complex structures.

Open Access: Yes

DOI: DOI not available

Enhanced Heat Recovery Network with Integrated Sensible Heat Storage Facilities for Energy Intensive Industry

Ákos Orosz Viknesh Andiappan Bing Shen How Tiffany Ang Ferenc Friedler

Publication Name: Chemical Engineering Transactions

Publication Date: 2025-01-01

Volume: 120

Issue: Unknown

Page Range: 19-24

Description:

Energy-intensive industries contribute large amounts of greenhouse gas emissions. An effective strategy to decarbonise these industries is by applying process integration tools to enhance energy efficiency and reduce overall energy consumption. Recent studies showed that thermal energy storage offers significant benefits in energy efficiency enhancement, as it can amplify the energy recovery potential. Despite its potential, studies that applied process integration tools to address heat recovery problems with consideration of heat storage remain limited. This work develops an optimisation framework that aims to determine optimal heat storage type and size based on the total annualised cost (i.e., costs associated with storage facilities and utilities) to form a feasible heat recovery network between plants. The proposed framework is demonstrated through a case study that focuses on optimising the sensible heat storage selection for indirect heat integration between a mixed plastic waste treatment plant and a steel mill. By analysing the performance and effectiveness of the storage media studied, nitrate salt storage medium is selected due to its greatest energy and cost savings of 12.7 % and 20.7 %, when compared to direct Heat Integration. Insights from this provide information on the feasibility of implementing a storage-supported heat recovery network in the energy-intensive industry.

Open Access: Yes

DOI: 10.3303/CET25120004

Structure and properties of closed-cell foam prepared from rPET

V. A. Szabó Gabor Dogossy

Publication Name: Iop Conference Series Materials Science and Engineering

Publication Date: 2018-10-18

Volume: 426

Issue: 1

Page Range: Unknown

Description:

Nowadays, in the field of packaging technology, one-way polymer packaging materials are increasingly used. Food and packaging industry uses the most, the life cycle of which becomes short, they become waste very quick. Also included are light weight bottles of polyethylene terephthalate (PET). Large amounts of waste can be handled with multiple options. The worst is their dumping on dump sites, as these materials do not compost. Their thermal recycling is more favorable due to their high calorific value, but a real cycle can only be achieved by their physical recycling. However, during the multiple re-purposing, PET's mechanical and processing properties are reduced. In our research, chemical foaming has been investigated, resulting in a smaller weight, better specific property, and fully reusable product. During our investigations, the structure and mechanical properties of recycled PET (rPET) specimens manufactured with different composition, chain and foam additives were analyzed.

Open Access: Yes

DOI: 10.1088/1757-899X/426/1/012043