Study on the parameters of steel plate reinforcement rib-deck crack considering local stress disturbances

Abstract

Local reinforcement will change the local stiffness distribution of the component, causing perturbation effects on the local stress of the fatigue detail. Only considering the reinforcement effect may lead to excessive strengthening and induce new fatigue-prone points. For the fatigue detail of the rib-deck weld, steel plate reinforcement test and numerical simulations were conducted. The stress changes of the deck weld toe and weld root before and after reinforcement were analyzed. The influence of parameters such as steel plate length, thickness, and width on the reinforcement effect of the weld toe crack and local stress disturbance was discussed, and reasonable parameters were recommended. The results show that after the cracking of the weld toe, the stress concentration locations at the weld toe and weld root of the deck shift from the center of the specimen to the crack tip. Steel plate reinforcement can effectively restrain the crack propagation, but can lead to an increase in the stress at the deck weld root within the reinforced area. A good reinforcement effect can be achieved while the steel plate covers the crack, and further increasing the steel plate length has limited improvement on the reinforcement effect but reduces the adverse effect of steel plate reinforcement on the stress of the deck weld root. Increasing the steel plate width will increase the adverse effect of steel plate reinforcement on the deck weld root stress, and it is recommended to use steel plates with a length greater than 120 mm and a length-to-width ratio greater than 4 for reinforcement. Increasing the width of the steel plate has a relatively small effect on the reinforcement effect and the stress at the deck weld root, and steel plates with the same thickness as the deck are recommended.