Харківський національний університет будівництва та архітектури Анотація. Розроблено математичні моделі повороту гусеничної машини. До механізму повороту включено гідрооб'ємну передачу і диференціальні редуктори. Їх введення поліпшує технічні характеристики об'єкта (керованість, маневреність, рухливість), знижує стомлюваність водія. Моделі дозволяють визначити параметри гідромашин і диференціальних редукторів, що забезпечують поворот об'єкта з необхідною швидкістю.
The increase in power and speed of modern units with internal combustion engines (ICE) leads to the increase in dynamic loads in them. The effective means of dealing with dangerous torsional vibrations is the introduction of elastic couplings and damping devices, the characteristics of which are most often nonlinear. The features of existing approaches for the choice of their parameters are limited by the imperfection of the models of the devices themselves, the features of the models of machine units with internal combustion engines as multimass systems with several nonlinearities. Goal. The creation of the method for parameters synthesizing of an elastic coupling with a preload as a unit of limiting excessive vibrations in nonlinear models of machine units with twinshaft diesel engines. The following problems should be resolved: the dynamic synthesis problem is formulated as a nonlinear programming problem; a harmonic linearization method was developed for the equations of motion in integral form; the equivalent stiffness and average deformation of the nonlinear connection are determined; an algorithm for finding the vibration amplitudes of nonlinear connections has been created; a reliable nonlinear dynamic model of a machine unit with a 3TD diesel engine has been built; the results of computational studies are compared with experimental data. Methodology. The synthesis method is based on an efficient algorithm for solving analysis tasks. The equations of motion are written in the form of integral equations using the pulsefrequency characteristics of the linearized models. The main advantage of this approach for solving synthesis and optimization tasks is that the number of equations of motion is equal to the number of nonlinearities and the complexity of solving the analysis task is practically independent of the model’s number of degrees of freedom. The problem of dynamic synthesis of coupling parameters is formulated as a nonlinear program-ming task. Results. The parameters synthesis method for the elastic coupling with a preload as a means of limiting excessive vibrations in nonlinear models of machine units with twoshaft diesel engines has been developed. A method of harmonious linearization for the equations of motion in integral form, written using the pulsefrequency characteristics of linearized models, is presented. The task of dynamic synthesis of coupling parameters is formulated as a nonlinear programming task. Originality. The parameters synthesis task of the elastic coupling with a preload is solved as a task of nonlinear programming. An efficient algorithm for solving the analysis task is based on the method of harmonic linearization for the equations of motion in integral form, that are written using the pulsefrequency characteristics of the linearized models. Practical value. The reliable nonline-ar dynamic model of a machine unit with a twoshaft transport diesel engine 3TD has been built. The optimal parameters of the elastic coupling between the engine crankshafts have been determined. The results of computational studies are compared with experimental data.
національний університет будівництва та архітектури 2 Національний аерокосмічний університет ім. М. Є. Жуковського «Харківський авіаційний інститут» Анотація. Викладено результати досліджень із розроблення математичної моделі динамічних процесів у перистальтичному бетононасосі з гідроприводом. Модель створена у формі диференціального рівняння щодо кута повороту ротора насоса; містить основні геометричні, масові характеристики ротора, динамічну характеристику гідромотора, параметри шлангу, будівельної суміші як середовища Бінгама. Установлено важливі технологічні закономірності функціонування пристрою. Результати роботи перспективні в процесі модернізації наявних та в розробленні нових моделей перистальтичних насосів.
The research results of the mathematical model development of dynamic processes in a peristaltic concrete pump with a hydraulic drive are presented. Cast concrete occupies a leading place in modern construction. Peristaltic concrete pumps are good proved in this area. Developing of devices for performance of such activities is an actual task. One of contemporary efficient directions in its solving is an adequate modeling of dynamic processes in mentioned devices. The model is development in the form of a differential equation for rotation angle of the pump rotor; contains general geometric characteristics, rotor’s mass characteristics, dynamic characteristics of the hydraulic motor, parameters of the hose and a structural mix. A method has been developed for the resistance torque forming to rotation of the pump rotor from rollers deforming the hose. A model of the friction forces during the movement of the structural mix is proposed. An expression is obtained for the resistance forces as result of gravity forces action on the mix particles in the outlet part of the hose. An approach is proposed for using catalog data to represent the torque of a hydraulic motor as a function of the angular velocity of its rotor. Researches of dynamic processes by using the proposed model are carried out. Important technological regularities of the unit functioning have been established, in particular: the mortar speed may have a significant variable component; the mortar speed and the pump performance increase with a decrease in the length of the outlet hose and a decrease in its height, a decrease in the rolling friction coefficients for the rollers, and not using of the side rollers. The conducted research show that an increase of an altitude leads to a decrease in the average speed of the mixture and the frequency of pulsations. In this case the amplitude of velocity pulsations increases. With an increase in the length of a deferent hose, the amplitude of velocity pulsations changes insignificantly. The rejection of side rollers leads to an increase in the average speed of the mixture motion with minor pulsations. The walls of the hose, however, in this case experience more intense bending stresses, which reduce the product life of the hose.
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