Advanced Materials Research Vol. 837

Abstract: In this paper characteristics of an AlMg/AlN composite produced in-situ and processed in a flowing N₂ atmosphere is investigated. Some critical parameters such as the manufacturing process temperature, the percentage of the magnesium consumed, the flowing reactive gas flow and the time for completing the manufacturing are considered as variables for the parametric investigation. Moreover, the effect of different amount of Mg employed has been also investigated, since Mg acts as a catalyst at the surface both for the gas/liquid and solid/liquid systems. Traditional methods were used for the basic characterization of the composite. The microstructure of the composite was investigated by optical and scanning electron microscopy (OM, SEM). SEM analysis was performed in order to observe the microstructural evolution as a function of the Mg content and to identify some reasons of the presence of porosity or any irregularities within the metal matrix. The evolution of mechanical properties, in terms of microhardness, at different percentage of Mg were monitored. By EDS technique the distribution of the elements was obtained. Furthermore, employing an optimization process, uniform dispersion of the strengthening (AlN) particles in the metal matrix with homogeneous properties along the composite material is obtained. Based on the aforementioned statements, it can be concluded that the reactions between Al, Mg and the N₂ atmosphere induce spontaneous infiltration in the metal matrix. The complete mix of properties and experimentally assessed parameters can be used for industrial purpose manufacturing design and development.

Abstract: The tested specimens are fibre-metal laminates. The samples are made as a connection between a metal sheet plate and a fibreglass laminate. Epoxy resins or polyester resins were applied in matrix of the composite. In this paper the exemplary results of testing on abrasion of composites with the fibreglass laminate plate were presented. Thanks to the results it is possible to estimate and compare the surface quality of the samples together with the joint of the fibreglass laminate. In assumed testing group of laminates, it is also possible to compare the impact of different basis weight of fabrics on the level of abrasive wear. The most proper material properties such as a type of connection or basis weight of applied laminate fabric were defined. In order to determine the degree of abrasive wear of tested samples and evaluate the testing results the methodology of research was assumed as: abrasive test and the visual valuation, measurement of mass decrement, measurement of geometrical structure of the composite's profile on the side of laminate. Taking into consideration the results of testing the weighed and calculated mass losses of the particular samples were compared. The measurements were taken in accordance with the EN ISO 12947-3:1998 norm.

Abstract: The fibre-metal laminates made of a steel plate and fibreglass laminate plate were tested in the special laboratory stands. Epoxy resin and polyester resin were used as matrix to fabricate the composites. The fibre-metal laminates combine advantages of metals and laminates. These materials have very good force versus displacement characteristics and overall mechanical properties. They are very popular and widely applied in technical systems. They can be put to use in connecting materials made of various fabrics, connecting high number layer laminates and most of all connecting metals and laminates. In this paper there are the results of testing fibrous composite materials connected in bolt joints presented. Composite materials reinforced with fiberglass, carbon and aramid fibers are considered. The impact of number of applied bolts in a joint on strength properties was investigated. The connections by means of eight or sixteen bolts were compared. A major problem of modelling the composites is assuming physical and material parameters of the analyzed elements.

Abstract: Bimetal actuators are frequently used in engineering applications. The literature for the design of bimetal actuators recommends only approximate analytical formulas for various bimetal structures, all with constant section on the entire length. No reference was found for bimetals with variable cross-section or bimetals shape optimization. Topology and shape optimization specialized software packages are not always an available or easy to use option. The paper presents a Finite Element Analysis, FEA, for a U-shaped bimetal with equal legs, considering both mechanical and thermal loads. FEA modeling aspects and some suggestions considering possible new shape modifications for this type of actuator are discussed.

Abstract: The paper presents a method based on the neural networks to study of working conditions, for the workstations from the manufacture industry. The neural networks were chosen because they excel in gathering difficult non-linear relationships between the inputs and outputs of a system. The neural network was simulated with Matlab. In this paper, we considered as relevant for the study of working conditions, 6 input parameters: temperature, humidity, noise, luminosity, load and frequency. The neural network designed for the study presented in this paper has 6 input neurons and 3 neurons in the output layer. Some experimental results obtained through simulations, are presented in the final part of the paper.

Abstract: This paper analyses the stress distribution of deposited cams by means of finite element method. The modelling of the internal tension state was made as a comparison between two types of cam mechanism configurations: a cam and plane cam follower with metallic coating deposited on the contact surface and cam with metallic coating and plane cam follower. The model used in the simulation was made in Solidworks. The model includes the geometry of the cam and cam follower and their assembly with coatings and the definition of the materials properties. The material properties used are those of 18MnCr11 for the base material and 40Cr130 for the coating. The defined geometric model was imported to the Static Structural module from Ansys 13.

Abstract: This paper focuses on the modelling, simulation and the performance analysis of a flexible manufacturing system using stochastic timed Petri nets so as to evaluate various performance parameters such as utilization rate of machines, deadlock detection, cycle time, and throughput rate of system in order to obtain the optimum productivity. The simulation of the manufacturing system using Petri nets provides the possibility to view the manufacturing process in time. Petri net model is implemented in Petri Net Toolbox under MATLAB environment. It is achieved the graphic construction of the net. Then, transporting it into a specific mathematical formalism it is made, so that the fulfiled structure to be fully retrieved and used to bring out the internal dynamics of the model. It is validated in this way the net topology, the evolution of (their dynamics), as well as the structural and behavioral properties (corresponding to checking if resources usage is stable and the model have no deadlocks). Some global performance indicators are determined in order to evaluate the performance of the proposed manufacturing system.

Abstract: Total hip arthoplasty or hip replacement is today a common and highly successful a surgical procedure. However, in the revision artoplasty the procedure is more complicated, as standard devices have to be adapted to different shapes of acetabular defects, which are patient specific especially when they are bigger and wider spread. This kind of big defects, sever acetabular defects, pelvic discontinuity, defects resulted from tumor problems, protrusion, can usually be addressed with a standard Burch-Schneider Antiprotrusio Cage or a Mueller Ring in order to restore the mechanics and the true center of the hip. This paper proposes a design process and manufacturing preparation for a patient specific acetabular cage. The design is intended to fix problems that standard cages sometimes do not resolve, for example insufficient fixation due to the fact that the inferior flange did not engage the ischium, problems of bone graft resorption and in the same time tries to remain an affordable solution. The design process uses as input information the 3D reconstruction of the patient hip from CT scan. Important parameters like the position of the true center of rotation, acetabular anteversion and inclination are determined and calculated. Other parameters, such as number of fixing screws and their designated holes or the amount of bone to be covered with the custom acetabular cage (fixation surface), are proposed by orthopaedic specialist. The design methodology relays on commercial software, such as Solid Works for CAD, 3D Doctor for 3D bone reconstruction from the CT scans or other software for different file transformations. The model was optimized to be produced through direct metal laser-sintering (DMLS). Regarding the results, the particular implant was designed and optimized for fabrication and it is available to be produced. During the design process, although a systematized process was undertaken and implemented, some activities could not be done in systematic, repeatable way. Nevertheless, a design process strategy was established, so that the design would match the requirements of such implant and also a requirements list for the type and form of information needed for this kind of design. Also, we concluded that using software to automate some of the operations that were done manually by the operator would help decrees the design time and improve the repeatability of the process.

Abstract: Real-time monitoring of the flow of materials, semi-completed and completed products during production process is necessary practice for every company because of need for optimal production management. Identification of technological operations, parts, products and persons responsible for any production stage is possible using means of processes control devices and automatic identification systems. Paper describes the in-line monitoring station designed for tests of real-time production monitoring methods. Available sources of information are RFiD, bar codes, and vision system. These data sources are integrated into the in-line production monitoring station. Modular production system model or small production system can be placed under the In-line station as an object of monitoring. Advanced PLC integrates control over subsystems and allows communication between hardware and software components of data acquisition system. Data acquired from the in-line research station is stored in a dedicated database, then processed and analysed using MES (Manufacturing Execution System) software.

Abstract: The perturbing presence of electromagnetic fields is responsible for numerous malfunctions in equipments operation. To eliminate these disturbances it is necessary both to reduce the electromagnetic radiation of electronic devices and to immunize them from the fields present in their operating environment. These requirements can be achieved by efficient shielding the source of the electromagnetic field and the receiver. The paper aims to develop new textile shield with spatial architecture, high shielding effectiveness, low manufacturing costs, shape diversity, mechanical elasticity and facile mounting. The shield were made by knitting and have a 3D spatial structure, with two external layers and an internal connection layer made with different combinations of conductive and non-conductive fibres.