The influence of diaphragm stiffening on welded tubular nodes in arch bridges

摘要

A tubular arch bridge is prone to fatigue damage, particularly in the presence of varying trafficrnloads. The intersection of various tubes at the nodes of a tubular structure constitutes a radicalrntransition of the geometry of the main tube. Due to geometric discontinuity, stress concentrationsrnare introduced at the nodes. Because the nodes are welded, other stress concentrations add up to thernformer ones, particularly near the weld toe of the joints. By introducing internal diaphragms insidernthe main tube, the stresses in the weld toe can be reduced. This paper focuses on decreasing the hotrnspot stresses at the weld toe, as a function of the diaphragm location. By lowering the stresses at thernweld toe, the fatigue resistance of the tubular arch bridge will be increased. To calculate these socalledrnhot spot stresses, accurate FE-models are being be assembled.