Dynamic processes of a vehicle moving over step – shaped obstacles

The study presents the development and analysis of a dynamic model, which simulates the loads induced on a tire of a vehicle as well as its suspension elements including their deformations when passing over a step-shaped obstacle. The possibilities of application of the quarter- and half-car models are considered. The models are used to analyze the influence of vehicle mass and suspension parameters on dynamic loads with the aim to provide recommendations and requirements for the development of active suspensions enabling to reduce dynamic loads generated when crossing over the considered obstacles

Coupling of energy flows from internal combustion engine and electrical motor in hybrid vehicle

Dynamical model of the hybrid electrical vehicle transmission with internal combustion engine and electrical motor driving the rear and the front wheels accordingly is developed. Particular elements in it are described using classical transmission elements. The model is used for the analysis of acceleration process when the engine and motor operate in non stationary regimes and transmission elements are in transition regimes of motion. Non linear models for clutch and wheel-road interaction description are used. The gear box control algorithm was developed and the vehicle prototype was constructed and tested. The experimental results proved the model validity. The difference in numerical and experimental results for the acceleration at 400 m. distance does not exceed 10 %. The model could be the background for the simplified control algorithm development with no mechanical link between the transmissions. Numerical modeling and experimental research show the functionality of the algorithm. The performed numerical modeling revealed that different from commonly used criteria for velocity ratios selection in the gear box are necessar

Measurement of sportsman‘s jump psychomotoric reaction

For representatives of sport games are very important components of physical abilities – spring and rate of psychomotoric reaction. For the following sportsman’s especially important is the rate of psychomotoric reaction, which defines reaction to the constantly changing ambience, similar to the sport action. Testing system, which simulates the situation of sports game, was created in the department of Informatics and biomechanics of LKKA. This system allows estimating the physical capabilities of player – spring and the speed of psychomotoric reaction. The speed of psychomotoric reaction is evaluated by making the jump-up. The influence of the height of jump-up on the spring and speed of reaction of sportsman is investigated. Considering the results of experiments and statistical analysis some recommendations are given and conclusions withdraw

Calculation of vibrations of an incompressible elastic structure

Rubber and photo-elastic materials at elevated temperatures exhibit incompressible behavior. The vibrations of a structure by taking the incompressibility constraint into account by the penalty method are analyzed. Reduced order numerical integration of the penalty term is performed. Graphical representation of volumetric strains at the points of reduced integration is proposed for validation of the calculated eigenmodes

Increase of productivity in brittle material processing by the application of intermediate elastic elements in tool structure

Productivity in ultrasonic treatment of materials is defined by a number of acoustic and technological factors. As the acoustic ones frequency, amplitude and type of oscillations and as technological – materials of the blank and the tool, the speed of relative motion, static pressure force of the tool to the treated part, type and dimensions of abrasive grains, concentration of the grains in suspension, treatment depth and conditions for abrasive flow can be mentioned. Typically these factors are interrelated. Nevertheless the influence of structural features of the applied acoustic systems is not yet studied sufficiently deeply. A new kind of ultrasonic tools with elastic elements in their structure are developed and researched what introduced the possibility to select the oscillation mode the most efficient for ultrasonic treatment together with the possibility of amplitude increase what in turn allows increasing performance characteristics of the tool if compared with the traditional rod shaped tool. Simulation of the elastic tool performance was carried out using simulation software package “ANSYS”. The impact of the forced vibration frequency on modal response of the elastic elements is shown in the paper

Coupling of energy flows from internal combustion engine and electrical motor in hybrid vehicle

Dynamical model of the hybrid electrical vehicle transmission with internal combustion engine and electrical motor driving the rear and the front wheels accordingly is developed. Particular elements in it are described using classical transmission elements. The model is used for the analysis of acceleration process when the engine and motor operate in non stationary regimes and transmission elements are in transition regimes of motion. Non linear models for clutch and wheel-road interaction description are used. The gear box control algorithm was developed and the vehicle prototype was constructed and tested. The experimental results proved the model validity. The difference in numerical and experimental results for the acceleration at 400 m. distance does not exceed 10 %. The model could be the background for the simplified control algorithm development with no mechanical link between the transmissions. Numerical modeling and experimental research show the functionality of the algorithm. The performed numerical modeling revealed that different from commonly used criteria for velocity ratios selection in the gear box are necessar

Coupling of energy flows from internal combustion engine and electrical motor in hybrid vehicle

Dynamical model of the hybrid electrical vehicle transmission with internal combustion engine and electrical motor driving the rear and the front wheels accordingly is developed. Particular elements in it are described using classical transmission elements. The model is used for the analysis of acceleration process when the engine and motor operate in non stationary regimes and transmission elements are in transition regimes of motion. Non linear models for clutch and wheel-road interaction description are used. The gear box control algorithm was developed and the vehicle prototype was constructed and tested. The experimental results proved the model validity. The difference in numerical and experimental results for the acceleration at 400 m. distance does not exceed 10 %. The model could be the background for the simplified control algorithm development with no mechanical link between the transmissions. Numerical modeling and experimental research show the functionality of the algorithm. The performed numerical modeling revealed that different from commonly used criteria for velocity ratios selection in the gear box are necessar

Calculation of stresses in the coating of a vibrating beam

The model for the analysis of stresses in the coating of a straight beam performing transverse vibrations is presented. The developed numerical procedure is based on the technique of conjugate approximation with smoothing adapted for this specific problem. Relative error norms are calculated and their relationship with the required smoothing is determine

Calculation of stresses in the coating of a vibrating beam

The model for the analysis of stresses in the coating of a straight beam performing transverse vibrations is presented. The developed numerical procedure is based on the technique of conjugate approximation with smoothing adapted for this specific problem. Relative error norms are calculated and their relationship with the required smoothing is determine

Measurement of sportsman‘s jump psychomotoric reaction

For representatives of sport games are very important components of physical abilities – spring and rate of psychomotoric reaction. For the following sportsman’s especially important is the rate of psychomotoric reaction, which defines reaction to the constantly changing ambience, similar to the sport action. Testing system, which simulates the situation of sports game, was created in the department of Informatics and biomechanics of LKKA. This system allows estimating the physical capabilities of player – spring and the speed of psychomotoric reaction. The speed of psychomotoric reaction is evaluated by making the jump-up. The influence of the height of jump-up on the spring and speed of reaction of sportsman is investigated. Considering the results of experiments and statistical analysis some recommendations are given and conclusions withdraw