新型抗拔不抗剪连接件的滑移性能及其滞回模型

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

新型抗拔不抗剪T型连接件能有效改善组合梁负弯矩区受力性能,该连接件可以保证钢构件与混凝土板不发生分离,允许两部分产生滑移从而降低传递至混凝土板的剪力,避免混凝土开裂。为研究该新型连接件的滑移性能,对6个试件进行了拟静力推出试验。试验结果表明该连接件在较低荷载作用下可以产生较好的滑移效果,连接件外包泡沫塑料的尺寸对滑移特征影响显著。试验的荷载-位移曲线反映出试件的刚度随加载历史发生了明显变化,滑移作用引起了曲线的捏拢现象。该文基于Richard-Abbott曲线提出了针对该新型连接件的滑移滞回模型,模型参数物理意义明确,并通过试验结果验证了该滞回模型的合理性。

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.