Model analysis of bucket wheel excavator SchRs 630 strength

Abstract

The possibilities of testing real constructions are often limited, especially in case of large constructions. The idea of model testing is to create a sub-scaled model in order to anticipate the behavior of the real construction, regarding the behavior of the model, with sufficient accuracy. The aim of this paper is to demonstrate that model testing of bucket wheel excavator structure, from the aspect of the strength of the constructions, is possible. In order to prove this assumption, firstly, numerical calculations of a real construction and its sub-scaled model were performed using the Finite Element Method. Sub-scaled structure is 10 times scaled real structure (in size and plates thickness). Within the static calculation, the analysis of the stress mapping from sub-scaled model to real structure was carried out, by partial groups of construction. The coefficients connecting stresses of sub-scaled model and stresses of real construction were formulated. Dynamic calculations of sub-scaled model and real structure were also performed. Then, a physical model was produced and subjected to experimental testing. Experimental testing was performed in order to verify the numerical models. A parallel testing of the model with strain gauges and a system for non-contact measurement of displacement and deformation was performed. High matching results were obtained of two experimental methods on one side, and numerical calculation on the other side. The physical model and the successful experiments carried out on it confirmed that these structures can be subjected to model testing, without important constraints and with sufficient accuracy.