SLIP PERFORMANCE AND HYSTERESIS MODEL OF A NEW TYPE OF UPLIFT RESTRICTED-SLIP FREE CONNECTORS

A new type of uplift restricted-slip free T-shaped connectors can effectively improve the mechanical performance of negative moment regions in composite beams. The connectors can prevent the separation of the concrete slab from the steel beam, reduce the shear force transferred to the concrete part, and delay the cracking of concrete. In order to investigate the slip performance of the new connectors, push-out experiments were conducted on six specimens under low-cycle load, and excellent slip performances were observed. The dimensions of the foamed plastic around connectors significantly affect slip performance. The phenomenon of stiffness changing and pinching is observed from experimental load-deformation hysteresis curves. Based on the Richard-Abbott curve, a new hysteretic model is proposed to simulate the slip effect of this connector. Parameters in the proposed model have clear physical meanings, and the predicted results are in good agreement with the experimental results.