Analytical study of the turns of bridge machines

Abstract

The research is devoted to the topical problem of the efficiency of turning wide-span bridge machines in the track farming system. The research aims to study the curvilinear movement along the soil traces of a constant technological track of an arbitrary multi-supported bridge machine, considering its design and method of turning, parameters, modes of movement and loading. Experimental studies were conducted, involving the use of a modern strain track and specially designed equipment for electrical measurements of non-electrical quantities. The processing of research data was carried out on a personal computer. A methodology for compiling private models of turning off the bridge vehicle moving along the soil trace of the constant technological track was developed. As a result of the joint solution problem of the bridge machine turning, it is possible to determine all output parameters of curvilinear motion: trajectory, tractive forces, turning radius, slipping, and actual speeds. The force interaction of the bridge machine’s undercarriage with the soil trace of a constant track is presented based on flat sliding with a variable anisotropic friction coefficient of adhesion φyd, depending on the properties of the track. As the radius of the wheel, the width of its tire and the air pressure in it, as well as the vertical load that acts on it, the coefficient of traction of the bridge machine φyd increases, which may cause higher slippage. The adequacy of the model of stationary turning of the overhead machine is confirmed by experimental estimation of the resistance coefficient of the power onboard turning. The convergence of the theoretical and experimental values of this coefficient is within the confidence interval ± σ in the whole investigated weight range of the bridge machine prototype. This allows us to assess the influence of design parameters and schemes on the turning characteristics as early as the design stage of a new bridge machine, thus optimizing the design process. The results of the research can be applied to the organization of the process of turning the existing models of bridge machines

Keywords

• controlled traffic farming
• gantry systems
• curvilinear motion
• coefficient of traction
• coefficient of adhesion
• front steered wheels