Investigation of tribological characteristics of lubricant grease based on Solidoil and urea resin thickener

The results of laboratory investigation of the tribological characteristics of a new grease based on Solidol, a polyurea thickener providing an increase in the dropping point to 118 °C, and a complex of additives are presented. It has been established that the proposed lubricant is efficient in a wider temperature range, provides higher antiwear properties for tribocoupling parts and considerably reduces friction losses during boundary lubrication in comparison with the original grease Solidol. The developed composition of the lubricant grease is supposed to be used when operating road construction machines in the tropical conditions of Vietnam.

Simulation of characteristics of composite material with «liquid» matrix

A theoretical model of composite material consisting of a fibrous reinforcing filler, epoxy and elastomer matrices is proposed. The main purpose of the elastomer matrix is relaxation of all stresses occurring under loading and blocking the crack growth. Such elastomer matrices were named as «liquid». The calculation of the stress-strain state of the developed composite material with «liquid» matrix was carried out by using the finite-element software Ansys. It was found out that when elastic characteristics of used elestomers were less, the level of maximal stresses was less and the load factor values were higher. Decreasing stresses results in the blocking of crack growth that leads to increasing durability of such materials.

Formation of mechanical properties of polymer composite materials with different types of hybrid matrices

The mechanical properties of polymer composite materials largely depend on the interfacial phenomena occurring on the interface between the matrix and reinforcing material. The addition of components to the matrix of polymer composite materials that retain their viscoelastic state during the molding process of the products makes possible to locally change the deformation-and-strength properties of a finished product, adapting it to the specified operating conditions. The viscoelastic components in the hybrid matrix form the third phase of the polymer composite material. Increasing the efficiency of interfacial layers of polymer composite materials with various types of hybrid matrices is the most important task of their development. The samples for microanalysis of the polymer composite material structure with various types of hybrid matrices were molded using the prepreg technology by vacuum molding on the basis of BT400 biaxial basalt fabric. Technical wax, anaerobic (Loctite 638) and organosilicon (Yunisil-9628) polymer materials were selected as the viscoelastic components of the hybrid matrix. In order to explain the reasons for the change in the deformation-and-strength properties of the obtained basalt plastics with various viscoelastic components in the composition of the hybrid matrix, microanalysis of their structure was carried out. A mechanism for choosing a scheme for the location of viscoelastic components in a matrix of polymer composite materials based on the provisions of combinatorial optimization is described.

Application of 3D-printing technologies for production of master-model in engineering industry

Analysis of 3D-printing methods used in the molding production to manufacture master-models has been carried out. The technology was selected, which allowed one to make high-precision parts, combining the molding and the 3D-printing. Factors effecting on the quality of 3D-models printed by this technology were analyzed. Experimental studied for determination of the printing parameter influence (layer thickness, filling percentage, printing velocity) on ultimate strength of specimens made of ABS-plastic were carried out.

Manufacturing support for porosity reduction of polymer composite material components

The main regulations for manufacturing support of the quality of polymer composite material components based on thermoplastic and thermosetting matrices are presented. Using examples of polymer composite material components, the effect of a molding technology and the chemical nature of a matrix on values of shrinkage and porosity was demonstrated. The effect of shrinkage and porosity on polymer matrices and composite materials based on different reinforcing materials is discussed.

System of identification and monitoring of technical state of land transport-processing machines

Formation problems of a system for identification, monitoring of the technical state and proactive maintenance of airfield land transport-processing machines by using diagnostic data are discussed. The main goal of development and implementation the proactive maintenance system is reliability control and operation safety of transport-processing machines. For the solution of this problem it is necessary to identify and prevent damages in proper time. It requires to assign the specific class of intermediate states named the pre- emergency state class. Logical and physical models describing changes in machine states, technological processes, geolocation, event visualization are discussed. The implementation results of the system of identification, monitoring of the technical state and remote proactive maintenance of airfield land transport-processing machines by using diagnostic data are presented.

Analysis of automation technology for quality management of surface layer during turning

Quality management of the surface layer during turning is one of the most relevant areas today. Study relevance is related to the fact that automated control is a promising strategy for manufacturers in the modern world. Automated tools improve the quality of products, as well as stimulate emerging innovations and eliminate gaps in existing production skills. Automated quality management of the surface layer during turning has been examined. The sub-tasks of this work are to study the main advantages of using metrological control devices, to prove the advantages of automated quality management of the surface layer during turning on a particular example, as well as to study the main terms and definitions. One of the main methodologies is theoretical research, as well as analysis of domestic and foreign publications related to a given topic. As a result of this study, imperfection proofs of modern technical means of non-automated quality management of the surface layer during turning are presented. Relevance and advantages of using the automated quality management technologies of the surface layer during turning are discussed.

Analysis of technological methods for glued-riveted joints in mechanical engineering (Patent review)

The patent review of various methods for producing glued-riveted joints of machine parts made of metals and composite materials is presented. The technologies for producing glued-riveted joints using both traditional types of rivets (exhaust or self-piercing) and capsules (with the possibility of reinforcement) filled with a viscous hardening paste; composite fiber rods; strands of glass fiber impregnated with a binder; rods of an under-polymerized polymer binder reinforced along its entire length with an alloy wire bundle with the shape memory effect are described.

Resistance evaluation of nonmetallic elements of pneumatic suspension of machines to influence of negative temperatures

The operation conditions of nonmetallic elements of the pneumatic suspension of road-making machines have been studied and analyzed. Evaluation of the strength characteristics of the nonmetallic elements of the pneumatic suspension under the influence of negative temperatures was carried out. It was found out by experiments that the influence of negative temperatures resulted in an increase in stiffness of a rubber part of an air cell. It was determined that for increasing resistance of the nonmetallic elements of the pneumatic suspension to the influence of negative temperatures it was necessary to use anaerobic impregnating compounds.

Treatment technology of carbon fibers under electromagnetic effects of different nature for production of high-durable carbon-filled plastics

The effect of pretreatment technologies of carbon fibers by different electromagnetic methods on their mechanical characteristics has been examined. The methods of cold plasma and ultraviolet radiation were used. Such a treatment improves adhesion strength of a metal coating with fibers for production of carbon-filled plastics with high interfacial shear durability. By experiments it has been found out that the plasma treatment method is the most effective. The study and experiment results are presented.