Advanced Research in Aerospace Engineering, Robotics, Manufacturing Systems, Mechanical Engineering and Biomedicine

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Authors: Rochdi El Abdi, Alexandru Dumitrache Rujinski
Abstract: Fiber-optic sensors are mostly used for in situ measurements of diverse chemical composition of industrial surfactants employed in industry as detergents, emulsifying and dispersing agents, coatings, and pharmaceutical adjuvants. These optical sensors are often used in wet chemical environments in which the temperature can be high.The purpose of this work is to study the mechanical behaviour of optical fibers in contact with CetylTrimethylAmmonium Chloride in aqueous solution (CTAC) at different immersion durations and different temperatures.Optical fibers were submitted to dynamic bending test under different velocities.Result analysis demonstrates that immersion in CTAC drastically decreases the fiber strength particularly when immersed for long aging periods at high temperatures.
Authors: Maria Cristina Dijmărescu, Dumitru Titi Cicic, C. Rontescu, Gheorghe Solomon, Mihai Ion Vasile
Abstract: In manufacturing industry there are many applications for the permanent joint of components of different shapes, but they are also very different in terms of chemical composition and structure [1, 2]. This paper is trying to find technological solutions of assembling by welding of two steels with totally different chemical composition, i.e. carbon steel S235JR + AR and austenitic stainless 316L. The process used for making the heterogeneous joint was Metal Inert Gas (MIG) with flux cored wire, numerically coded 137. The paper presents the effects of welding technology, through heat input, such as hardness. Variations of hardness values determined in the joint areas are presented, as well as the chemical composition of the welded joint obtained using the flux cored wire T 23 12 LPM 1/C1, according to EN ISO 17633 - A.
Authors: Afshin Mohammadhosseini, Darren Fraser, S.H. Masood, Mahnaz Jahedi
Abstract: The wear of polymeric bearing material in contact with metallic biomedical implant has often been the main cause of long-term clinical failure of such implants. Very few studies seem to have been undertaken to investigate the wear behaviour of Ultra-High-Molecular-Weight-Propylene (UHMWPE) bearing material in contact with titanium alloy implant material under various loading conditions. This research paper presents an investigation on the wear properties of UHMWPE under dry and wet sliding conditions at different loading conditions. In this study, the well-known pin-on-disk equipment was used to carry out the sliding wear test. The titanium pin was made by Electron Beam Melting (EBM) technology and machined to rub on the UHMWPE disk. The aim is to understand the wear characteristics of UHMWPE in relation to Ti6Al4V alloy under various loading and lubricating conditions. Results include volume loss and wear rate analysis.
Authors: Gheorghe Matache, Cristian Puscasu, Alexandru Paraschiv, Oana Trusca
Abstract: Thermal sprayed Mo coatings deposited on steel support deposited by electric arc and atmospheric plasma spray were investigated. Microstructural investigation of the coatings showed that in both variants the splats formed by rapid solidification and splashing during the impact with the substrate have irregular shape, exhibit cracks and scattered debris. The measured average equivalent diameter of the splats and the calculated average diameter of the particles that generated the splats are higher for electric arc spraying. Using the measured and calculated data it was descibed the relathionship between splats diameter, splats thickness and flattening degree. Some intrinsec properties of the coatings as roughness, hardness and bond strength were measured. All these properties are influenced by the splat size. Lower size of the splats lead to reduced surface roughness, higher hardness and higher bond strength of the coatings.
Authors: Camelia Boboc
Abstract: Processing by thermal spray metallization is a process widely used in industrial area. Surface Coatings systems using electric arc spray metallization opens up a range of new possibilities for refurbishing and bringing the parameters according to the technical documentation, the main objective is to ensure a high resistance to wear and corrosion. Through this research I set a schedule to settle the experimental influences how technological parameters on interface material - deposited layers.
Authors: Mihaela Suciu, Mihai Sorin Tripa, Lucia Ghioltean, Daniela Paunescu
Abstract: This paper presents an original work about the calculus of fatigue resistance to limited durability for a desmopan membrane, a thermoplastic polyurethane membrane. For this research we needed the values of stresses, determined by Finite Elements Method (FEM). In order to apply FEM, we needed mechanical characteristics of thermoplastic polyurethane membrane, characteristics that have been determined by Digital Image Correlation Method. Mechanical characteristics and geometrical characteristics, with loadings too, are input for FEM soft. The calculus of fatigue resistance to limited durability serves to reliability studies of the thermoplastic polyurethane membranes, that diaphragm pumps are equipped.
Authors: Susana Sfechiş, Mihail Abrudean, Diana Monica Sas, Mihaela Ligia Ungureşan, Iulia Clitan, Vlad Mureşan
Abstract: The paper presents a solution for modeling and simulation of the adsorption process of the sulfur dioxide in natural zeolites. The adsorption process is modeled as a distributed parameter process, its dynamics depending on three independent variables: time and two spatial variables. In order to simulate the adsorption process, an original form of the approximating analytical solution which describes the process work in dynamical regime is proposed and used. The coefficients of the approximating analytical solution are determined using experimental data obtained from the real plant. A direct practical application, resulted through the simulation of the obtained mathematical model, is the approximation of the time period in which the saturation of the zeolites of different dimensions occurs. Having the mentioned time period, the operators from the industrial field can decide with precision the moment when a zeolite block has to be replaced in order to avoid the environment pollution.
Authors: Dan Prodan, Anca Bucuresteanu, Adrian Motomancea, Emilia Balan
Abstract: This paper shows several issues related to decrease in electric power consumption for hydraulic systems of modern machine tools, especially CNCs. A core element in the structure of such systems is the pneumo-hydraulic accumulator. Here, examples are shown for hydraulic systems destined to locking and unlocking of skids and to opening of tool holders. This paper shows mathematical models, diagrams, simulations and certain experimental executions.
Authors: Silviu Nastac, Carmen Debeleac, Cristian Simionescu
Abstract: Computational dynamics of technological equipments dealing with intensive, shock-like and various working regimes frames the area of this research paper. A widely used type of demolition-cutting equipment supplied by hydrostatical driving system was adopted, and ordinary scenarios of equipment exploitation have been proposed in order to dignify the very short but strong transitory states deeply depending on the material characteristics and the regime parameters. Elastic, dissipative and plastic components have been considered to compose the global characteristic of the processed material interacting with cutting tool. The authors propose a simplified rheological model intended for modeling and simulation of demolished structural elements based on composite materials, like reinforced concrete. This model is very useful for simulation the variable dynamics of the interaction between the demolition-cutting equipments and the composite elements in order to evaluate the parameters evolution within the process, and obviously, to optimize driving system for minimize transitory effects and vibratory evolutions. The advantage of this computational approach results from the reduced resources involved by simulation tasks, taking into account the global evaluation of the resistant forces usually required for this kind of behavioral analysis.

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