Análise estrutural de sobrechassi modular para guindastes articulados

Abstract

Knuckle Boom Cranes can be installed on the body of cargo vehicles, but these structures are not originally designed to withstand the additional stresses generated during load lifting. To mitigate this problem, metal structures are installed on the vehicle chassis, designed to absorb the forces exerted by the crane. The main functions of the subframe used in crane installation are to protect the vehicle chassis and increase the rigidity and stability of the assembly. The main challenge to be overcome in the development of new subframe is the need to accommodate large cranes while maintaining a low beam profile height for better use of the cargo body. This work deals with the structural verification process of a modular subframe assembly with reduced height for large cranes. Three structural analysis methods were used: (1) Analytical calculations performed in accordance with standard EN12999. In this stage, initial results were obtained for the maximum stress acting on the assembly, allowing the LNE 380 material to be determined for the manufacture of the assembly; (2) analysis of the initial finite element method, with the modeling of the subframe together with the auxiliary components of the assembly, such as the chassis, stabilizers, and an initial representation of the vehicle suspension. Through the use of simplifications such as modeling components with Beam and Shell elements, results were obtained regarding the theoretical behavior of torsions and stresses acting on the assembly during equipment operation; (3) Experimental tests on the proposed superstructure assembly, with the application of strain gauges and load cells to collect data at points defined by the stress results found in the numerical model. The process was completed with new analyses of the finite element method in the model updated according to experimental tests, evaluating the possibility of using simplifications to improve the performance of the numerical model for application in future projects. The results found during analytical calculations and experimental tests present favorable conditions for the application of the proposed superstructure, obtaining safety factors above those required by the standard, which are used for the structural approval of the component. The stress results obtained in the numerical analyses showed good convergence with the experimental data in cases of loading that predominantly generate bending in the structure. However, as the loads promoted flexural-torsional effects on the structure, the numerical results began to diverge from the experimental ones. This indicates that the numerical model and its boundary conditions should be revised in future work to improve the convergence of results. [resumo fornecido pelo autor]