Modeling the swing of mobile loader cranes with anchor outriggers when operating on weak soils

Abstract

The paper presents a dynamic model illustrating the swing of a mobile machine on a wheeled chassis equipped with a loader crane and anchor outriggers during loading and unloading operations. The model regards the interaction effect of the outrigger anchoring device with weak soil within the system “load – loader crane – chassis – outriggers – anchor devices – soil”. Possible variants of single and multiple step soil compaction and changes in its deformation characteristics in the area of the outrigger anchor device implementation are considered. The impact of the gaps formed during soil compaction on the swing parameters of a mobile machine during the swing of the boom of the loader crane is demonstrated as applied to a full-scale crane-manipulator. The rate of chassis tilt angle and swing period of the mobile machine increase during the loader crane operation with an increase in the gaps in the ground. The swing parameters during the initial stage of crane operation gradually increase for soils characterized by multiple compaction until these parameters reach some steady-state values determined by soil stiffness. Awareness of the steady-state value of the crane tilt angle amplitude achieved at the end of the process of weak soil compaction enables to reasonably assess the risk of a mobile machine overturning.