Sarach

pp. 103-125

The paper presents the structure and mathematical model of a prospective test and measurement exercise bench for development and evaluation of performance of special equipment of fast cars. The mathematical model of the stand includes a car dynamic model when driving on uneven terrain, and a model of the vibrational platform of the stand. The use of the model allows to adequately identify the driving power of a real stand.

The article describes a method of determining power requirement for drives of prospective test and measurement exercise bench in order to develop and evaluate performance of special equipment in fast cars. The method is based on mathematical modeling of machine dynamics when driving on uneven terrain and simulation of body movements obtained in the model of vibrational stand platform. With the proposed method it was possible to determine the capacity of drives to simulate the dynamics of the housing for a high-speed track-type vehicle.

This paper describes the existing constructions of cushioning systems of transport vehicles. The main advantages and disadvantages of each system were identified; a modernized cushioning system on the basis of the existing cushioning system of TV with HMP was developed. A comparative study was carried out by means of simulation of soft riding of transport vehicles with existing and planned cushioning systems. Field tests were conducted for one of the existing systems. The authors analyzed adequacy of the model and drew conclusions regarding the most promising ways of upgrading existing cushioning systems. This work shows the direction of possible upgrading of existing systems and improving the accuracy of selection of elastic and damping characteristics of suspension.

Along with widely used theoretical methods of research of internal dynamics with use of imitating mathematical simulation, only natural tests can provide the final conclusion about working capacity of a design and correctness of a choice of options. Natural tests also allow to verify imitating mathematical models that is to estimate their adequacy and accuracy. The mathematical model of a two-volume pneumo-hydraulic spring (PHS) suspension brackets of new generation automobile platforms of average and big load-carrying capacity was developed. Benchmark tests of the natural sample of such PHS to check the adequacy of the developed model and research of behavior of a design were conducted at various kinds of loading. It was shown that the mathematical model described the processes, proceeding in a design two-volume PHS, precisely enough.

Required level of a damping of multi-basic oscillatory system depends on character of external indignation. In connection with this, regulation of the characteristic of damping, depending on operating modes of amortization systems, is one of the basic directions of their further improvement. This direction for improvement of quality of suspension systems of multi-wheeled vehicles (MWV) with quantity of axes more than three is rather perspective. Mathematical model and design procedure of design parameters of a pneumo-hydraulic spring with counter-pressure and two-level damping were developed for operated suspension brackets of MWV. The example of calculation of spring for suspension bracket of the MWV with the wheel formula 8x8 in the lump of 60 tons was included in this article.

The required level of damping a multi-basic oscillatory system depends on the character of external disturbance. In connection with this, regulation of the characteristics of damping, depending on operating modes of amortization systems, is one of the basic directions of their further improvement. This direction for improving the quality of suspension systems in multi-wheeled vehicles (MWV) with the quantity of axes more than three is fairly promising. The authors show that for multi-wheeled vehicles, due to a narrow-band low-frequency spectrum of fluctuations of the case, the characteristics of damping which provides automatic reception in the zone of resonance of attenuation factor nearly 
ψ =0,4 … 0,6 on longitudinal-angular and vertical fluctuations irrespective of the weight of object and change of restoring force, was desirable. At the same time in the above-resonance zone, the damping level should be reduced, which leads to a significant decrease of vibro-load of the MWV. This leads to the necessity of creation of a suspension bracket of variable structure where there is an automatic change of the damping level depending on the kind of road roughness impact on the MWV. Two levels are enough: the basic (high), and low which joins only in the case of high-frequency road profile influence. The design procedure of elastic and damping characteristics of a suspension bracket with two-level damping was developed. The example of calculation for the MWV with the wheel formula 8x8 in the lump of 60 tons was included in this article.

This article contains an example of track mathematical model. Discussed previously developed similar models and listed their shortcomings. The new model is designed to work with transmission, suspension and running gear models and requires low computation time. A qualitative verification of the adequacy of track mathematical model was provided.

 This article contains an example of a track-type vehicle transmission model. Transmission is made on the basis of a valve-inductor linear motor. The authors consider the issues of mathematical modeling of a valve-inductor linear motor. The main emphasis was placed on universality of a geometric configuration modeled engine. The authors suggest a method for creating mechanical characteristics of the motor using a simulation model.

In article the estimation of efficiency of the law of management by a corner of folding of sections articulated tracked vehicle which use raises smoothness of a course of the car at the expense of decrease in amplitudes of longitudinal-angular fluctuations section is presented. Application of the given law of management allows to raise average speed of rectilinear movement of the car, with restriction on smoothness of a course, more than on 75 %

The article describes a new analytical dependence for definition of average speed of rectilinear motion of a caterpillar with restrictions on cushioning system. The peculiarity of this dependence consists in taqking into account the hyperbolic sector of speed ability. It is shown that formula usage allows to receive a more authentic estimation of the average speed of a caterpillar, which is especially important for definition of loading and durability of suspension members elements.

In article the algorithm of management by a corner of folding of sections articulated tracked vehicle which use raises smoothness of a course of the car at the expense of decrease in amplitudes of longitudinal-angular fluctuations section is presented.