Applied Mechanics and Materials Vol. 729

Abstract: The article reports on a hot topic over the last few years and the issue of recycling and further use of secondary raw materials from the solar panels. Recycling of solar panels is very difficult and complicated. Secondary materials that recycling generated so far have not found a application and their using is still not fully resolved. The research conducted on Brno University of Technology, Faculty of Civil Engineering (BUT) now being developed polymer materials used for industrial floors. These materials were incorporated secondary materials as fillers. It was thus replaced by a filler made from natural materials, which the Czech Republic is still declining. In the following text, which builds on earlier publications describe the procedures and results of new tests, which were conducted on these fuels, which confirms the possibility of the use of glass from solar panel in industrial polymer flooring systems.

Abstract: The influence of chromium cast iron Cr8 treatment by Fe-45Si-6Mg-0,5REM modifier on the structure, phase transformation and heat resistance was studied experimentally.It is demonstrated that during modifying of chromium cast iron Cr8 the alloying effect takes place. The initial cast iron structure which consists of alloyed ferrite, carbide (Cr,Fe)₇C₃ and cementite (Fe,Cr)₃C is transformed as in the process of chromium alloying according to modifier consumption increase. At the modifier consumption of 0,15 % the mass quota of cementite (Fe,Cr)₃C decreases from 3,2 % to zero, and the mass quota of carbide (Cr,Fe)₇C₃ increases from 20 % up to 30 %.

Abstract: This paper presents an experimental investigation of heated tool welding of polypropylene matrix composite. The goals of this paper are to investigate the issues of local changes of welding strength that depends on heating time. For experimental procedure, specimens were injection molded as ISO tensile test specimens and matrix was reinforced by organic and inorganic materials. In addition, welding of specimens was carried out by non-contact heated tool butt welding process. Within the range of the weld process parameters were investigated, the highest weld strength dependent on heating time was achieved of the order of 94% to the base strength of the material. And then these specimen’s maximum welding strengths and energy at break point properties that were depend on heating time have been compared.

Abstract: Aluminum foam has been widely used in aviation and spaceflight, ships, cars, transportation, construction, petrochemicals, telecommunications, etc. For decades, scholars have done a lot of research work. Mature and stable production preparation process of aluminum foams has been possessed. At present, the practical application design and production has becomes a hot issue. Based on analysis a flood of literature, aluminum foams owned mechanical properties and application, property evolution after filling thin wall tube; all were inductive research and reviewed in the paper. Moreover, material structure design factor, experimental comparisons, application in the automobile industry, development situation, as well forecasted its market prospect, all this were summarized. Suggestions on aluminum foam applications in the automotive industry had been proposed. Consequently, promote the process of the research efforts on the application of aluminum foam in the car, provide to designer and research worker with reference.

Abstract: An L-proline-catalyzed synthesis of amino thiazoles is described here. Amides and 2-mercapto thiazoles were used as the starting reagents. Various reaction conditions were screened, and the scope of various amides and 2-mercapto thiazoles has been examined. Most of the substrates gave high yields. Compared with traditional synthetic methods with transition metal as catalyst, this protocol uses organocatalyst L-proline. It will reduce environment pollution and save the synthetic cost.

Abstract: α-Hydroxy amides are a class of important intermediates in organic synthesis. It plays an important role in the field of science and medicine. However, the preparation methods of α-hydroxy amides are relatively few, and they are usually enzyme-or Lewis acid-catalyzed reactions. These types of methods are not ideal in operation, yield and/or stereoselectivity. We found a new way to synthesize α-hydroxy amides by transforming amino acids into α-hydroxyl acids, and then by amination of the α-hydroxy acids.

Abstract: In this study, multi-objective optimization of stacking sequences for laminated composite composite beams is studied for simply supported boundary conditions. A unified three-degrees-of-freedom shear deformable beam theory is used for analytical solution and genetic algorithm is used as optimization technique. By use of two different parameters such as the deflection and frequency together in a pre-defined fitness function, optimization process is carried out in order to maximize the fitness function. Initially, the deflection, frequency, fitness function values and corresponding stacking sequences are presented for various number of layers and increment of fiber orientation angle. The variation of the fitness function with respect to deflection and frequency depending on the number of generations are presented.

Abstract: Dynamic stability parameters (dynamic derivatives) are important indicators for the control system design, orbit design and longitudinal and horizontal dynamic stability analysis of aircrafts. Methods that evaluate the quality and dynamics of an aircraft typically include flight experiment, wind tunnel testing and theoretical calculation, with one of the most important part of them being the obtainment of dynamic derivatives. Project estimation method derivative action is not considered suitable for boundary layer transition, flow separation and re-attached and the complex situation leeward area vortex small angle of attack linear range. Frequency domain is a dynamic non-scheduled periodic invariant system to get moving derivative calculation method, but the accuracy of the unsteady flow is much lower than the time-domain calculations. Currently, unsteady CFD approach represents a time-domain nonlinear aerodynamic characteristics predicted the most advanced level. Derivative prediction efficiency and adaptability under conditions of high angle of attack of the development trend of nonlinear dynamic derivatives were analyzed. As a global trend, obtaining dynamic parameters through numerical calculation is becoming a prevailing approach to dynamic parameter research.

Abstract: Based on the analysis of the flight stability, the research progress of the unsteady aerodynamic model was comprehensively introduced. Bryan, first of all, the aerodynamic load of traditional dynamic derivative model is put forward, still used today in some engineering issues. However, Bryan state parameters of the model is not complete, not exactly reflect the unsteady aerodynamic force time history effect and nonlinear effect. Etkin models, by retaining the item of high order Taylor expansion, including the influence of nonlinear effect. Improved Etkin model can explain the actual flight of some of the common transient response, including due to stall the mutation and aerodynamic force/torque caused by unsteady flow dynamic bifurcation and chaos of the aerodynamic force/torque value and uncertain phenomenon. Finally, the unsteady flow field of a reduced order model development trends and application prospect were analyzed, and pointing out that the CFD simulation is still accurately predict the plane stability and handling the most important method.

Abstract: In the pressure die casting process, a great attention is paid to a die castings quality improvement. This quality has to be ensured with a great reliability and, at the same time, it is necessary to apply control methods to a technological process which provide a complete picture of a die casting process as well as internal quality of the produced die castings. It requires control of the present technological factors of a pressure die casting process. The contribution deals with the effect of die casting plunger velocity inside a filling chamber on mechanical properties of a die casting product from EN AC 47100 alloy.