主索鞍位移滑动副结构模型试验研究

Model Test Study of Sliding Pairs in Main Cable Saddles of Suspension Bridge

为选择更适合的主索鞍位移滑动副材料,以燕矶长江大桥为背景开展试验研究。参照该桥主索鞍位移滑动副的构造和边界条件,制作钢-不锈钢、无储脂坑的聚四氟乙烯(PTFE)板-不锈钢、有储脂坑的PTFE板-不锈钢和改性聚甲醛(POM)减摩层板-不锈钢4组滑动副材料短尺寸滑块,通过顶推试验测试4组滑块的滑动摩擦系数和结构强度,再优选2组滑动副材料制作长尺寸滑块,观察顶推试验后滑块的变形和破坏情况并进行比选。结果表明:4组短尺寸滑块在良好润滑条件下的滑动摩擦系数分别为0.083、0.017、0.013和0.018,PTFE板-不锈钢滑块在试验后均发生了塑性变形,屈服强度均低于13.59 MPa,改性POM减摩层板-不锈钢和钢-不锈钢滑块的结构强度显著大于PTFE板-不锈钢滑块;优选有储脂坑的PTFE板-不锈钢和改性POM减摩层板-不锈钢进行长尺寸滑块试验,试验后有储脂坑的PTFE板-不锈钢滑块顶推力逐次增大,变形明显,改性POM减摩层板-不锈钢滑块的表面无变形,无破坏;改性POM减摩层板-不锈钢滑块的滑动摩擦系数与PTFE板-不锈钢滑块接近,结构强度显著大于PTFE板-不锈钢滑块,为推荐的位移滑动副材料。

The study focuses on materials suitable to make sliding pairs of main cable saddles in the suspension bridge.Referencing the construction and boundary conditions of the sliding pairs of Yanji Changjiang River Bridge,four groups of short sliders of sliding pairs materials were prepared,including the materials of the steel-stainless steel,PTFE plate-stainless steel,PTFE plate with lubricating oil holes-stainless steel and stainless steel-wearing-resistant plate overlaid with modified polyformaldehyde(POM).Jacking tests were performed to verify the sliding friction coefficients and structural strengths of the four groups of sliders,and two groups were selected out,and the materials were used to make long sliders.After the jacking test,the deformation and damages of the sliders were compared.It is demonstrated that being well lubricated,the sliding coefficients of the four groups of short sliders were 0.083,0.017,0.013 and 0.018,respectively.The slider of PTFE plate-stainless steel plastically deformed,with yielding strength below 13.59 MPa.The structural strengths of the stainless-steel-wearing resistant plate overlaid with modified POM as well as the steel-stainless steel are greater than that of the slider of PTFE-stainless steel.The stainless steel-PTFE plate with lubricating oil holes and the stainless steel-wearing resistant plate overlaid with modified POM were selected out.After the test,the jacking force imposed on the stainless steel-PTFE plate with lubricating oil holes kept rising,and the deformation of the sliding pair was obvious.No deformation and damage were observed on the surface of the slider of stainless steel-wearing resistant plate overlaid with POM.The sliding friction coefficients of the slider of the wearing resistant plate overlaid with POM-stainless steel approximate each other.The structural strength is higher than those of the PTFE plate-stainless steel,which is worth a recommendation.