Use of Physicochemical Modification Methods for Producing Traditional and Nanomodified Polymeric Composites with Improved Operational Properties

Various aspects of the methods of physical and physicochemical modification of components of filled thermo-plastic composite materials are analyzed, aimed at improving the surface properties of the fillers and the technological properties of the polymer matrix during their interaction. It is noted that the improvement of the interfacial interaction of the components of polymer reactoplastic composites, including adhesive strength, is a key factor for improving the reliability of the cured filled composite. As a promising area of research, a modification of the surface of the reinforcing fibrous filler and the technological characteristics of the liquid polymer binder, aimed at increasing their contact properties in the composite was chosen. The effectiveness of the physical method of modifying the components of composites in the form of low-frequency ultrasonic processing is described. The peculiarities of cluster formation and physicochemical modification of epoxy polymers filled with dispersed fillers are analyzed. Attention is focused on the effectiveness of ultrasonic processing in cavitation mode for deagglomeration and uniform distribution of nanoparticles in a liquid medium during the creation of nanocomposites. Experimentally confirmed the improvement of the technological properties of liquid epoxy polymers, modified by ultrasound, used for the impregnation of oriented fibrous fillers, as well as the improvement of the physicomechanical properties of the sonicated epoxy matrices

Creation of Structural Polymer Composite Materials for Functional Application Using Physicochemical Modification

The various aspects of physico-chemical modification of the components of structural materials of functional application based on classical composites and nanocomposites are analyzed. Potential applications of such materials are briefly described. Ultrasonic cavitation treatment is considered as a basic method of physical modification when obtaining the indicated classes of composites. The influence of ultrasonic treatment modes on the technological and operational properties of reactoplastic polymers, as well as on the hardening of reinforced composites based on them, is investigated. Technical means of ultrasonic cavitation processing of liquid binders and polymer composites based on them are briefly described. An effective spectrum of interrelated structural and technological parameters of ultrasonic treatment has been characterized, which is established by calculation and experimentally-statistically. The design issues of the technological processes of obtaining polymer composites of functional application are analyzed. The efficiency of creating carbon fiber composite materials, as well as the prospects for creating of these materials based on reinforcing fabric with nanomodified fillers is described. The methods of obtaining functional nanomodified carbon-composites with improved physicomechanical and operational properties, in particular with increased strength and electrical conductivity, are characterized. The effectiveness of the ultrasonic treatment and production of nanomodified thermoplastic composite materials by extrusion method is considered. Some issues of forming products from intelligent polymer composites are analyzed. The results of the survey can be used in the design of advanced technologies for the creation of functional polymer composites of functional application

Computer Variant Dynamic Forming of Technical Objects on the Example of the Aircraft Wing

This article describes a mathematical apparatus of dynamic formation of technical objects on the basis of a study that has devised it with the aim to improve and develop computerized structural and parametric geometric models by appropriate integration with their available mathematical support. The practical value of the obtained results consists in creating a methodology for computer variant dynamic shaping, which helps flexibly combine the designing and manufacturing of technical objects, as is illustrated by the example of the wing of an aircraft. The proposed techniques provide an automated design of the wing surface and a computer simulation of such technological operations for manufacturing a centreplane longeron as cutting, pressure treatment, assembly, etc. The created structural and parametric geometric models contribute to the multicriteria optimization of technical objects throughout the lifecycle. The described approach can also be used for the computer variant dynamic formation of such structural units of the airframe as ribs, panels, sections, bends, and the like. Through further studying, the research materials can be distributed to diverse products of mechanical engineering and other industrie

Modeling the Structures of Oriented Macrofiber Polymer Composites as Capillary-Porous Bodies

The problems of modeling the structure and design of technical parameters for forming of oriented macrofiber polymer composites are analyzed. The considered approaches are based on the application of geometric modeling of the structure of oriented fibrous fillers and the design of the parameters of technical means for forming oriented macrofiber polymer composite materials. Peculiarities of the application of the phenomenological and structural approaches to the design of structural and technological parameters of technical means and to the calculation of the elements of composite structures based on oriented macrofibrous fillers are considered. The technique for determining the structural characteristics of oriented macrofibrillar fillers based on its adequate geometric model as capillary-porous bodies is given. As the structural characteristics, the porosity, the specific internal surface, and also the effective (hydraulic) capillary radius of oriented macrofibrous fillers are considered. It is noted that the obtained structural models are used, in particular, to the prognosis of the design and technological parameters of the technical means for molding macro-fiber polymer composite materials

Modeling the Resonance of a Swinging Spring Based on the Synthesis of a Motion Trajectory of Its Load

The paper reports a technique for building the resonance trajectories of the motion of a swinging spring load. A swinging spring is the kind of a mathematical pendulum consisting of a point load attached to a weightless spring. The other end of the spring is fixed immovably. We have considered the pendulum-like spring oscillations in a vertical plane provided its axis straightness is maintained. Calculations have been performed based on the solutions to a system of differential equations with components that include values for the frequency values of vertical and horizontal displacements of a point on a spring.The relevance of the subject is predetermined by the necessity to study the technological processes of dynamic systems when the nonlinearly connected oscillatory components of the system exchange energy. Using a swinging spring phenomenon illustrates the exchange of energies between the transverse (pendulum) and longitudinal (spring) oscillations. In this case, we also take into consideration the influence of the initial conditions for initiating oscillations. Of particular importance is to study the resonance state of a swinging spring when the frequency of longitudinal oscillations differs by a multiple number of times from the frequency of transverse oscillations. In addition to a common «classic» case (resonance 2:1), there is a need to consider cases with different values for the frequency ratio. The result is the derived geometric shapes of the motion trajectory of a swinging spring load that correspond to the patterns in the state of its resonance.The results obtained in the current paper make it possible, by using a computer, to synthesize the motion trajectory of a swinging spring load that would match the assigned frequency ratio of longitudinal and transverse oscillations. For this purpose, in addition to basic parameters (a load's mass, rigidity of the spring, its length in a no-load state), we added the initial values for the parameters during oscillation initiation. Specifically, the «starting» coordinates for a load position, and the initial load motion velocities in the direction of the coordinate axes. We have considered examples of building a load motion's trajectories for cases of resonances the type of 2:1, 7:3; 9:4; and 11:2. The results obtained are illustrated by the computerized animations of oscillations of appropriate swinging springs for different cases of resonance.The results could be used as a paradigm in order to study the nonlinear connected systems, as well as in the calculation of variants for mechanical devices where springs affect the oscillation of their elements. Additionally, for cases when the technology of using mechanical devices necessitates abandoning the chaotic movements of loads in order to ensure the periodic trajectories of their displacements

Development of A Geometric Model of A New Method for Delivering Extinguishing Substances to A Distant Fire Zone

A geometric model of a new method of delivering fire-extinguishing substances to a fire zone located at a considerable distance was offered. The idea of delivery is based on the mechanical action of throwing. To this end, a substance (e.g. extinguishing powder) is loaded in a hard shell made as a special container. After delivery by means of a launcher to a fire zone, the container has to release the substance which will promote fire extinguishing.The known method of remote delivery of extinguishing substances uses a pneumatic gun with a cylindrical container. During delivery, the cylinder must rotate around its axis to ensure flight stability. The cylinder is rotated by a special turbine when passing through the gun barrel. There are difficulties in regulating the distribution of compressed air flows during the turbine operation. In addition, the tightness of the pneumatic part of the gun should be monitored.The new delivery method uses a container in a form of two spaced loads similar to a sports dumbbell. The dumbbell motion is initiated by simultaneous action of explosion-generated pulses directed at each of its loads in a pre-calculated manner. This results in the rotational motion of the container. To describe the dynamics of the dumbbell motion, a Lagrangian was defined and a system of Lagrange differential equations of the second kind was set up and solved. Examples of modeling trajectories of the centers of masses of the dumbbell loads taking into account air resistance were given.The proposed method is planned to be a basis of a new fire extinguishing technology. This is evidenced by the new scheme of launching the dumbbell by means of explosion-generated pulses of charges of two pyro cartridges. The obtained results make it possible to estimate magnitudes of explosion-generated pulses necessary for throwing and corresponding distances of the dumbbell deliver

Development of A Geometric Model of A New Method for Delivering Extinguishing Substances to A Distant Fire Zone

A geometric model of a new method of delivering fire-extinguishing substances to a fire zone located at a considerable distance was offered. The idea of delivery is based on the mechanical action of throwing. To this end, a substance (e.g. extinguishing powder) is loaded in a hard shell made as a special container. After delivery by means of a launcher to a fire zone, the container has to release the substance which will promote fire extinguishing.The known method of remote delivery of extinguishing substances uses a pneumatic gun with a cylindrical container. During delivery, the cylinder must rotate around its axis to ensure flight stability. The cylinder is rotated by a special turbine when passing through the gun barrel. There are difficulties in regulating the distribution of compressed air flows during the turbine operation. In addition, the tightness of the pneumatic part of the gun should be monitored.The new delivery method uses a container in a form of two spaced loads similar to a sports dumbbell. The dumbbell motion is initiated by simultaneous action of explosion-generated pulses directed at each of its loads in a pre-calculated manner. This results in the rotational motion of the container. To describe the dynamics of the dumbbell motion, a Lagrangian was defined and a system of Lagrange differential equations of the second kind was set up and solved. Examples of modeling trajectories of the centers of masses of the dumbbell loads taking into account air resistance were given.The proposed method is planned to be a basis of a new fire extinguishing technology. This is evidenced by the new scheme of launching the dumbbell by means of explosion-generated pulses of charges of two pyro cartridges. The obtained results make it possible to estimate magnitudes of explosion-generated pulses necessary for throwing and corresponding distances of the dumbbell deliver