Untersuchungen zu geklebten Beulsteifen im Stahl- und Verbundbrückenbau

Investigations on bonded stiffeners in steel and composite bridges. Numerous bridges are in poor condition. In particular, resistance to plate buckling is a problem. Strengthening of buckling-prone sections in steel bridges is often difficult due to non-weldable steels and the additional notch effect from conventional joining techniques. The use of adhesives for fixing stiffeners allows material-friendly reinforcement of buckling-prone steel sections. Prior to practical application, numerous questions must be answered with regard to the detailing of the stiffeners, the stress on the adhesive layer due to inhibiting buckling, the load-bearing capacity of the adhesive layer, the resistance to aging and fatigue. On the basis of numerical and experimental investigations, a simple fracture condition could be developed which allows a design of the adhesive layer‘s load-bearing capacity. A sufficient stiffening effect of the bonded stiffener is given as long as the adhesive layer‘s load-bearing capacity is sufficient. The aging and fatigue behaviour was investigated in basic tests. It was possible to define boundary conditions that enable resistance for a limited time, but there is still need for further research in this field.