Análise numérica de ligações tipo KT de treliças de aço tubulares com banzos de seção quadrada e circular

Abstract

Structures with tubular trusses as a structural solution have become usual in Brazilian designs, over the last few years, therefore it is required to study the behavior of these structures, with interest on the joint behavior, which are usually submitted to complex requests and becoming the most critical point of the tubular structure governing the structure design. Several works have been conducted to evaluate the ultimate resistance and influence of geometric parameters on joint strength. However, the dispersion of the experimental and numerical results in relation to the design standards prescriptions is still high, therefore, it is necessary to develop works that thoroughly evaluate the behavior of these joints to make their sizing more secure and inexpensive. This work analyzed the structural behavior of welded KT-joint with gap of steel trusses with circular hollow section (CHS) or square hollow section (SHS) chord members and circular hollow sections braces members. A numerical model was developed to represent KT-joint considering the material non-linearity and the weld. A finite element model was developed in commercial software ANSYS Mechanical v.17. The models were compared with experimental results available in the literature. A parametric study was carried out to analyze the influence of geometric parameters on joint strength and stiffness and the numerical results were compared with the main normative prescriptions on the subject. Conclusions about the theoretical and numerical behavior, variation of the initial stiffness and the evolution of the stress in the chord were obtained, as well as the influence of geometric parameters on the joint ultimate strength.