Testing and Diagnostics of Carbon Polymer Composite Materials by Radio Wave Method Used in Aircraft Construction

The article is devoted to the applicability of radio wave methods of testing and diagnostics of aviation composites for newly launched products. The description of the measurement process is also considered by the method of integral equations.

Influence of the prolonged form of lysocyme in the composition of polyurethane implant on cells and tissues in vitro and in vivo.

Background. The development of biocompatible polymeric implant materials and providing them with biological activity is an urgent task that can significantly increase the effectiveness of such materials when used in medical practice. Objective. Investigation of the interaction of connective tissue culture matrix cells with a prolonged form of the proteolytic enzyme lysozyme as part of a polyurethane implant in vitro and study of the effect of this form on cells and tissues during implantation in experimental animals in vivo. Methods. In order to study the possible cytotoxicity of the components of polymer composite materials and the effect of lysozyme on the growth and development of the culture of fibroblastic elements, studies were performed by tissue culture in vitro. Polymeric composite materials based on polyurethaneurea without and with lysozyme were implanted into the body of white laboratory rats of the Wistar line. Cellular responses of the body after implantation were studied by light microscopy by analysis of histological micropreparations. Results. Biological studies have assessed the effect of prolonged lysozyme on cells and tissues in vitro and in vivo. Conclusion. The fibroblast tissue culture method showed the effectiveness of biologically active polyurethaneureas with prolonged release of lysozyme, which was expressed in the prolongation of the dynamics of growth and development of cellular elements in vitro. It has been shown that lysozyme in the composition of polymer composite materials had a biological effect and helped to reduce the cellular response to the implantation of polymer samples, accelerating the formation of connective tissue capsules around the implants.

Designing of ship shafts made of polymer composite materials

В работе предложены процедуры для выполнения проектировочного расчета судовых валов из полимерных композиционных материалов. Рассматривалась цилиндрическая оболочка, являющаяся основным телом промежуточного судового вала. Она сформирована из пакетов монослоев, состоящих из армирующего волокна и связующей матрицы. Определяющей нагрузкой на судовой вал принят крутящий момент. Заданы ограничения на параметры напряженно-деформированного состояния, характеризующие формы отказов для оболочки в целом и пакета монослоев. Получены аналитические зависимости, связывающие параметры проектирования с крутильной жесткостью, касательными напряжениями потери устойчивости оболочки и нормальными напряжения в волокне. При заданных характеристиках материала проектирование сведено к определению радиуса и толщины оболочки вала. Выполнена серия проектировочных расчетов, различающихся типом активных ограничений. Полученные варианты проектирования проанализированы с помощью метода конечных элементов. Произведена проверка удовлетворения всех ограничений. Предложены условия проектирования, обеспечивающие приемлемые варианты проектов валов из ПКМ. The paper proposes procedures for performing the design calculation of ship shafts made of polymer composite materials. The cylindrical shell, which is the main body of the intermediate ship shaft, was considered. It is formed from packages of monolayers consisting of a reinforcing fiber and a binding matrix. The determining load on the ship's shaft is assumed to be the torque. Restrictions are set on the parameters of the stress-strain state that characterize the failure forms for the shell as a whole and the monolayer package. Analytical dependences linking the design parameters with torsional stiffness, tangential stresses of the shell loss of stability and normal stresses in the fiber are obtained. With the specified material characteristics, the design is reduced to determining the radius and thickness of the shaft shell. A series of design calculations, differing in the type of active constraints, has been performed. The obtained design options are analyzed using the finite element method. The check of satisfaction of all restrictions is made. The design conditions that provide acceptable variants of shaft designs from PCM are proposed.

Chip formation processes based on orthogonal processing of polymer composite materials

This paper presents the results of the study of processes occurring in the cutting zone during the processing of polymer composite materials. The research included determining the effects of orthogonal cutting conditions, such as the cutting depth t and cutting rate v, on the tangential component Pz of the cutting force, the length lc of chips, as well as the vibration acceleration W, to clarify the results previously submitted to the scientific community and obtain new data. The study included 12 experiments for different cutting conditions with the cutting depth t varying in the range of 0.1—0.4 mm and the cutting rate — in the range of 6.7—30.2 m/min. The experimental results allowed to determine a range of cutting rates that lead to a low level of elastic deformations of reinforcing fibers. Based on the dynamics of increasing cutting forces in various cutting conditions, tool cutting edge wear, type and length of chips, as well as the vibration acceleration dynamics, we have found that reinforcing composite material fibers accumulate on the tool cutting edge, while elastic fracture of these fibers causes defect formation on the processed surface. The analysis allows giving recommendations on the need for research in the field of abrasive machining with rigid grinding wheels due to the highest hardness of the cutting tool surface, increased machining speed and the possibility of self-sharpening during tool wear.

Repair technology features of main elements of road-building machines’ hydraulic system with use of polymer composite materials

Features of the operation and typical damages of standard hydraulic systems’ elements of road-building machines have been analyzed. The occurrence reasons of defects and the elimination ways of them were determined. Methods for eliminating the defects were analyzed, and it is shown that one of the most promising methods for eliminating the defects in liners of hydraulic cylinders and hydraulic lines is the use of polymer composite materials with a fibrous or dispersed filler for the repair.