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As the progress is made in vehicle dynamics analysis, tire models for vehicle dynamics analysis that are broadly applicable have been increasingly sought. Therefore, following the previous paper, the method to formulate a tire model consisting of theoretical and experimental equations, that represents, with high accuracy, the experimental characteristics of a tire, based on relatively simple theoretical equations - by obtaining the coefficients through experiments and further adding to them appropriate collections - is investigated in this paper. In the previous paper, the procedure to formulate a model that shows the changes in lateral force, driving-braking force and aligning moment, generated on a tire running at a constant velocity, due to slip angle, slip ratio, camber angle and load was presented. However, the change due to velocity was not taken into consideration.

Easy-to-use tire models for vehicle dynamics analysis have been studied at various institutions. This paper presents a tire model consisting of theoretical and experimental equations representing the experimental characteristics of tires, by employing relatively simple theoretical equations (1), (2), (3) and (4)*, obtaining their coefficients through experiments, and adding further corrections. As a result, we have obtained a model representing the change of forces and moment generating in the tire, which are caused by slip angle, slip ratio, camber angle and load. This model has many advantages including easy correspondence to physical phenomena, higher possibilities of practical development and a possibility of rational correction of the errors during experiments.

The Japan Automobile Research institute (JARI) has determined that it is possible to improve the performance of multilayer soundproofing boards in automobiles while at the same time reducing their weight. The JARI tested the acoustic properties of multilayer soundproofing boards used in automobile floors, dashboards, and roofs, to obtain data on sound transmission loss, impact sound reduction levels and sound absorption coefficients for these components. These data were then subjected to multiple regression analysis, which provided information on the acoustic effects of soundproofing board materials, including asphalt sheet, felt, carpet, etc. Regression modelling was then used to determine how altering the weight and thickness of component materials would affect acoustic performance. The results of these simulations were confirmed in actual testing.

In order to obtain correction formulas applicable to aerodynamic force measurements in the JARI full-scale wind tunnel, correlation tests were carried in 1983 between the MIRA and JARI full-scale wind tunnel, with three different types of vehicle. The comparison of results, especially for zero-yaw-angle drag coefficient, shows that JARI measures, on the average, some 2.5 % above MIRA. The next year, in 1984, we investigated the causes of the difference in drag measurement between the two wind tunnels, and found that the most significant cause is a horizontal buoyancy due to static pressure gradient in the JARI test section which might be attributable to distortion in parts of the walls of the test section over many years.

A tire vibration model which helps to clarify a vibration characteristics of radial tire in affecting vehicle ride quality and road noise is studied. The model is based on cylindrical beam on an elastic foundation, and cylindrical beam is characterized by bending stiffness, tension force and mass of tread band with breaker. Elastic foundation correspond to radial and tangential direction stiffness of side wall. The natural frequencies under inflation pressure are determined analytically by using of this model, further, measurement techniques of fundamental values in the model are examined and experimented. It is found that the analytical natural frequencies of radial tire agree well with the corresponding experimental results in a wide range of inflation pressure. Finally, an effect of foundamental values of tire on natural frequencies is discussed.

Dynamic properties of motorcycles are, to a great extent, governed by motorcycle tire properties. In this study, the influences of various factors such as, internal pressure, load, tire make, width, etc., on tire dynamic properties are clarified through the experiments carried out on laboratory testing machines. It was found that tire dynamic properties are significantly influenced by these factors, and the experiments yielded some beneficial data for the improvement of motorcycle dynamic properties as well as tire dynamic properties.

Contact and collision accidents of automobiles are spatial, and measurements of the path and its dispersion of the automobile and evaluation of operating performance from these measurements are important. There is residual path measuring equipment but there is a demand for more modern equipment. The author has developed equipment to automatically measure the position of an automobile by triangulation using laser beams and to process the data using a computer. This article will explain this equipment and give the results of some experiments in which this equipment was used to test automobile control as application examples.

This report deals with the tests made on the hydroplaning phenomenon of car, truck and bus tires using the interior of a dynamic tire testing machine. For car tires, the relationship between braking force and slip ratio and between cornering force and slip angle as affected by hydroplaning were investigated. Studies were also made of the influence of the difference between radial-ply and cross-ply tires, inner pressure, load, thickness of the water film, etc.. Next, a study was conducted concerning the effect of hydroplaning on the cornering properties of truck and bus tires.

The cornering properties of tires while a vehicle is traveling generate a curve different from those in steady state derived from prevailing tire-testing devices. The objective of this paper is to clarify the cornering properties in order to simulate vehicular motions and to make the results applied to practical use. This paper presents experimental data on steady-state tire cornering properties at slip angles of 0 to 90 degrees and on transient tire cornering properties up to relatively large slip angles. This research deals with transient tire cornering properties at slip angles of 0 to 90 degrees.