Failure prediction of butterfly-shaped steel plate shear keys under cyclic loadings

Abstract

A novel energy dissipation shear key (BSP shear key) is proposed using multiple butterfly-shaped steel plates arranged in parallel for small-to-medium-span highway bridges. Two series of quasi-static experiments have been conducted to investigate the influence of loading protocols on the energy dissipation behavior of the BSP shear keys. Based on the test results, a simplified bilinear model is developed to represent the force-displacement skeleton curves of the BSP shear keys subjected to different loading protocols. And the force-displacement hysteretic curve of the BSP shear keys is decomposed into the skeleton part and the Bauschinger one. The energy dissipation capacity of the BSP shear keys can then be approximately calculated by adding the energies dissipated by the two parts respectively. The energy dissipation of the skeleton part can be determined using the simplified bilinear model and the one of the Bauschinger part is derived according to the loading protocols. The calculated energy dissipation capacity of the BSP shear key specimens can be validated by the test results with the maximum error of 13.9%. Finally, a flowchart is proposed to predict the failure of the BSP shear keys based on their energy dissipation capacity under cyclic loadings. The prediction results indicate that the proposed flowchart can capture with a satisfactory accuracy the failure of the BSP shear keys due to their energy dissipation capacity being exhausted. This study demonstrates that the failure prediction is feasible based on the energy dissipation capacity of the BSP shear keys.