Dynamic analysis of the joint movement of the hoisting and slewing mechanisms of a boom crane

Abstract

To increase the productivity of boom cranes, the operation of individual mechanisms is combined. At the same time, dynamic loads on structural elements, drive mechanisms and loads on a flexible suspension increase, which reduces the reliability of crane operation and increases energy losses. Therefore, the research aims to consider the problem of the dynamics of the joint movement of the mechanisms for load slewing and hoisting of a boom crane. To study the dynamics of the joint movement of the mechanisms, the boom system was represented by a mechanical system with 6DOF, where the basic movement of the mechanisms and the oscillatory movement of the structural links with elastic and dissipative properties, as well as the load on a flexible suspension in the plane of crane slewing and hoisting were considered. For such a mechanical system of a crane, the differential equations of the joint motion of the crane slewing and hoisting mechanisms were developed. The obtained equations are a system of the second order nonlinear differential equations, for solving which a numerical method in the form of a computer program was used. Using the developed program, the dynamics of the joint movement of the mechanisms of a jib crane with specific numerical parameters were calculated. Based on the calculations, a dynamic analysis of the joint movement of the mechanisms for slewing and hoisting the load of a jib crane with a hoisting boom was carried out, which revealed high-frequency vibrations of links with elastic and dissipative properties, as well as low-frequency oscillations of the load on a flexible suspension. The greatest impact of oscillations is observed during the start-up of mechanisms, where high-frequency oscillations dampen during the transient process, and low-frequency oscillations dampen over a fairly significant period. To improve the dynamic properties of the mechanisms for turning and hoisting a load during their joint movement, it is proposed to optimise the mode of movement in the areas of transient processes (start-up, braking). The research results can be used in the development and operation of cranes in mechanical engineering, construction, and other industries