The dynamic stability of a crane standing on soil during the rotation of the boom

In this work the influence of flexible soil foundation on the dynamic stability of the boom crane is presented. This analysis was made during the rotation of the boom, such that variable pressure on the soil and other deformations could be taken into account. The rheological deformation of the soil as a function of the changing strain in time has been described by an equation, which is the Duhamel integral. After accepting the discrete model of the considered system dynamic equations of motion were elaborated, which because of their nonlinearity and complexity were solved numerically. Appointed were the dynamic displacements of each of the supports for different rotational speeds of the boom, showing the influence of the rheological deformation of the soil on the behaviour of the whole crane. As well the trajectories of the motion of the weight hoisted were presented for different rotational speeds of the boom, which enabled the analysis of the precision of the positioning of the weight being hoisted (minimization of oscillation).