Mathematical modeling of cargo oscillations on the mobile machine manipulator load lifting body

Abstract

Hydraulic crane-manipulator devices mounted on a movable chassis of different transport and technological machines are widely used in various sectors of the Russian economy. The main objective of handling system operation is movement of cargo or working body to the desired point of space. Therefore, dynamic loading of handling system is largely determined by the nature of the interaction with cargo or working body. The paper discusses approaches to assessing the impact of cargo on loadbearing metal structure of mobile machine manipulator. The mathematical models of cargo oscillations on rigid and flexible fixture are developed. Motion equations are integrated together with motion equations of handling system. Dynamic model of cargo oscillations on rigid and flexible fixture are considered. The results of mathematical modeling of cargo oscillations on rigid and flexible fixture are provided. Stiffness of handling system was determined using the finite element method. Mathematical modeling helped to find out that cargo oscillations on load lifting body cause additional dynamic loading on loadbearing metal structure of mobile machine manipulator. For jib cranes dynamic factor when determining dynamics of cargo impact is usually taken equal to 1.1 ... 1.3, and on the basis of the calculations the dynamic factors when using flexible fixture can reach values of 1.5 ... 2.0. Therefore, in the calculation of impacts from the side of cargo it is recommended to use the developed model. Dynamic loads for rigid fixture are lower than when using flexible cargo fixture. Dynamic factor in this case lies in the range of 1.05 ... 1.1.