Daniel Lepădatu

Daniel Lepădatu
Gheorghe Asachi Technical University of Iasi | TU Iasi · Department of Civil And Industrial Engineering

Associate Professor PhD
Teaching in civil engineering Topography and physics of buildings

About

50
Publications
15,090
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
191
Citations
Citations since 2016
15 Research Items
94 Citations
201620172018201920202021202205101520
201620172018201920202021202205101520
201620172018201920202021202205101520
201620172018201920202021202205101520

Publications

Publications (50)
Article
The circular economy is a development model that redefines economic growth by decoupling it from the consumption of resources (especially non-renewable) and conveys waste back into productive activities, as raw materials for other production circuits, thus helping the increase of resource efficiency, and reducing the impact of economic activity in...
Article
This paper presents the design of some equipment within an installation for plasma processing of liquid hazardous waste with hydrogen. The authors present the design and simulation in Solidworks and Ansys of hydrogen plasma torches components used for heat treatment of hazardous industrial liquids, the development in Matlab & Simulink of algorithms...
Article
The paper presents a synthesis of the main technologies used in municipal waste management, highlighting the main technical characteristics, advantages and disadvantages, the main objective is to improve the technical and economic performance of a plant that uses an innovative and environmentally friendly technology based on hydrogen plasmas for th...
Article
Full-text available
Optimization of civil engineering systems is a complex process that includes both theoretical and practical knowledge of experts from different disciplines. Optimization is defined as a rigorous process by which the methods corresponding to an engineering problem are analyzed and selected. The objective of this scientific paper is to define an opti...
Conference Paper
Full-text available
The monitoring of civil engineering structures in service stage that could represent a major risk in case of structural degradation is mandatory. In this context, the methods or techniques used to achieve this objective require primarily human, financial and material means that can generate very high costs. This paper will present a multicriteria o...
Article
Full-text available
This paper presents a modern electric heat treatment which has implemented an electric furnace control system through thermoregulatory with PID control laws. An important aspect is the development of a mathematical model for controlling electrical heating systems for heat treatments based on mathematical modelling to predict the mechanical properti...
Article
Full-text available
Our proposal for this paper is to diversify the architecture of neural networks in order to optimize it and to obtain the best performing configurations that minimize errors of predictive mechanical properties of polymeric concrete. In this paper different architectures of artificial neural networks will be used for investigating the flexural stren...
Article
Full-text available
This paper presents the research undertaken by the authors to determine the parameters of electric power produced by a photovoltaic panel using flexible semiconductor polymer cells, aiming a comparative study between this panel and other types of conventional photovoltaic panels, with monocrystalline, polycrystalline and amorphous silicon, based on...
Article
Full-text available
In the topographical surveying works devices have got among the required accessories also tools called tripod. They have the role of correctly installing and settling the equipment above the station point in order to perform the measurements. Various types of tripods are known: the classic tripod (made from aluminum or wood), the adjustable laser t...
Article
Full-text available
Neural networks are a series of simple mathematical models, created on the architecture of human brain which gives a superior capacity of learning based on numerous connections established among neurons. The artificial neural networks have strong units of processing which are characterized by an extreme simplicity, but because of their whole intera...
Article
Full-text available
Constructions composed of mortars and cement concretes are exposed to advanced nitrate ion corrosion processes if they are used in aggressive mediums, specific to nitrogen fertilizer industry. The paper aims at tracking down the behavior of cement mortars with a high content of slag (75%) exposed to nitrate ion corrosion as well as carrying out a a...
Article
Full-text available
Sustainable development is a modern concept of adaptation conditions for achieving objectives that respond simultaneously to at least three major requirements: economic, social and environmental. Achieving sustainable development cannot be accomplished without a change of mentality of people and without communities able to use resources rationally...
Article
Energy performance of buildings, assessed along design stage or rehabilitation phases during service life, is directly influenced by the manner thermal bridges are approached, being that their unavoidable presence in structures affects the risk of surface condensation and the level of thermal comfort. A realistic evaluation of these responses depen...
Article
Full-text available
The influence of coal fly ash and glass fiber waste on the tensile strength of cement concrete was studied using central composite design. Coal fly ash was used to replace 10% of the cement in the concrete mix. Glass fiber was added to improve the tensile properties of the concrete in different dosages and lengths. In total, 14 mixes were investiga...
Article
This paper aims to optimize the spatial coordinates of the locating terminals points of our faculty, initially determined using GPS technology. Additional measurements were performed to one year interval with another GPS receiver. So was obtained a new set of coordinates that was used to obtain a better determination thereof by the average of the t...
Article
Full-text available
The use of different types of waste for obtaining new building material is a possibility for capitalization the large quantities of wastes which result every year. Polymer concrete with additions continues to develop because in many situations by introducing fine materials in the mix, the properties can be improved and the cost is lower. The study...
Article
The objective of the present paper consisted in the verification of a foundation soil improved with vibrated ballast columns. The construction site under consideration is characterized by localization in an area with high hydrostatic level and uneven difficult foundation soils. In case of construction works on sites with these particular features,...
Article
The road works at getting hot bituminous mixtures and not only an important requirement of bitumen is to wet better natural aggregates. In order to ensure a stable connection between aggregate and bitumen are used increasingly more frequently in the addition (doping) of bitumen, i.e. bitumen mass addition of small amounts of additive (0.1-0.5%). Al...
Article
Full-text available
In the last decades new types of concrete had developed or improved their properties. Polymer concrete is used more and more in the construction domain because it has some advantages in comparison with cement concrete, such as: high strength, corrosion resistance and rapid hardening. However, the high cost of polymer concrete is the most important...
Article
In the paper the Artificial Neural Network - ANN was used for prediction the mechanical characteristics such as flexural strength and split tensile strength of polymer concrete with silica fume. Neural network modeling generated the mixes with the lowest cost and maximum strength. The association of these two materials has unpredictable effects on...
Article
Taking into account the multiple possibilities of using these wastes in the present paper is presented the capitalization of protein residues powder, obtained by their incineration, introduced as addition in cement concrete. The study of cement concretes obtained by using different types of wastes is an actual necessity because of the huge quantiti...
Article
This paper describes a methodology to perform the local proper network of supporting points in order to be used in practical applications of Surveying discipline. The usefulness of these points is obvious by the fact that it involves greater responsibility in addressing land measurement techniques and puts the students in a real situation with the...
Article
Full-text available
The aim of this study is to analyze data produced by a parallel application using statistical investigation methods like design of experiments to determine faults in the design or implementation of the application. Using this technique we develop a model to verify the design of a parallel application by determining the factors influencing its perfo...
Conference Paper
The development of new materials with fly ash offers new scientific and technological perspectives due to the specific interesting physical properties of these materials. Geopolymer binder can be used as a complete replacement of conventional cement to produce concrete for structural applications. Geopolymer binders can be produced from waste mater...
Conference Paper
In the paper the authors present the results of experimental researches made on fly ash polymer concrete. Fifteen mixes designed based on the mixture design of experiments concept for the minimum content of resin were tested and the mechanical properties were analyzed with statistical method. The aim of this work is to identify how the polymer conc...
Article
In manufacturing process, the quality of final products is significantly affected by both product design and process variables. However, historically tolerance research primarily focused on allocating tolerances based on product design characteristics of each component. This work proposes to expand the current tolerancing practices, and presents a...
Article
The aim of this study is using a statistical investigation to analyze data from mixture experiment design and involve regression models to determine the response surface of polymer concrete. The experimental studies were realized on polymer concrete prepared of epoxy resin, Silica Fume (SUF) and aggregates. The combinations were designed based on t...
Article
Full-text available
The aim of this paper is to present a statistical investigation, for analyzing the buildings characteristics from the energy efficiency point of view. The energy efficiency of buildings may be estimated by their capacity to ensure a healthy and comfortable environment, with low energy consumption during the whole year. The glazed areas have a decis...
Article
Full-text available
The aim of this paper is to present an approach for developing material models, using a statistical investigation, for analysing the mechanical characteristics of polymer concrete. The experimental studies were realized on polymer concrete prepared of epoxy resin, silica fume and aggregates. The mix combinations were designed based on the mixture d...
Article
Full-text available
Finite element method was developed to be applied in case of the elastic materials. If this method is applied on reinforced concrete elements and structures, the results are affected by errors because this material doesn’t have an elastic behavior on loads. Because the reinforced concrete has cracks in service, the evaluation of reinforced concrete...
Article
Full-text available
In this work we propose the optimization strategies using numerical designs of experiments to minimize the difficulties in the metal forming process optimization. Among these difficulties it can recall : springback from bending process, die wear during extrusion process or tools fatigue, the research of global solution for data exchange between num...
Article
Full-text available
The aim of this paper is the statistical process control analysis of the tool wear evolution during metal extrusion process for better understanding the principal causes that generate the variability of such a complex phenomenon. The wear prediction is carried out using finite element simulation including the Archard wear model. The tool wear model...
Article
Evaluation of residual mechanical characteristics for reinforced concrete structures is an actual problem in Romania where, a lot of buildings were designed and erected before year 1963 when the first seismic norms appear. For these buildings it is necessary to check the level of structural safety because the structures take-over more earthquakes w...
Article
The aim of this paper is to propose an original optimization approach using the concept of computational design of experiments and response surface methodology to check the curvature in numerical experiments. Generally, for the study of the strongly nonlinear phenomena, it is recommended to use a second-order model. This paper proposes a new techni...
Article
The aim of this work includes the springback optimisation of bending processes using the concept of experimental design and response surface methodology (RSM). The optimisation method includes two phases. The first involves the objective function prediction using design of experiments and response surface method, while the second is an optimisatio...
Conference Paper
In manufacturing process, the quality of final products is significantly affected by both product design and process variables. However, historically tolerance research primarily focused on allocating tolerances based on product design characteristics of each component. This work proposes to expand the current tolerancing practices, and presents a...
Article
in manufacturing process, the quality of final products is significantly affected by both product design and process variables. However, historically tolerance research primarily focused on allocating tolerances based on product design characteristics of each component. This work proposes to expand the current tolerancing practices, and presents a...
Article
Full-text available
In manufacturing process, the quality of final products is significantly affected by both product design and process variables. However, historically tolerance research primarily focused on allocating tolerances based on product design characteristics of each component. This work proposes to expand the current tolerancing practices, and presents a...
Conference Paper
The aim in this paper is the die lifetime optimization for the multiple response in metal extrusion process. The main objective of the multiple response optimization is to improve the quality of a product or process by minimizing the effects of variation without eliminating the causes (since they are too difficult and so expensive to control). Usin...
Article
In this work, the design of experiments method has been used for a better understanding of the influence of the deviation of the material parameters on the damage evolution within the workpiece. To predict the evolution of the material deterioration during the processes, a damage model accumulation has been implemented in a finite element code and...
Article
Full-text available
The aim of this paper is to provide a general finite element model allowing for the numerical prediction of the extrusion die wear which allows for the evaluation of the die life. A wear prediction model has been implemented in the finite element code Abaqus in which the tool wear is a function of the normal pressure and some material parameters. T...
Conference Paper
The aim of this paper is the statistical process control (SPC) analysis of the tool wear evolution during metal extrusion process for better understanding the principal causes which generate the variability of such a complex phenomenon. The wear prediction is carried out using finite element simulation including Archard wear model. The tool wear mo...
Article
Full-text available
Dans ce travail nous proposons des stratégies d'optimisation par plans d'expériences numériques pour palier les difficultés rencontrées dans le processus d'optimisation de procédés de mise en forme. Parmi ces difficultés on peut rappeler : le retour élastique durant le pliage, l'usure de la matrice pendant l'extrusion ou la fatigue des outils, la r...

Network

Cited By