Analysis And Experimental Research On Anti-sliding Performance Of Cable Clamp With Full Lock Coil Strand In High Stress State

The cable clamps were key connection joints in the cable structure.If the anti-sliding bearing capacity was insufficient,the clamps would slip on the cable body,which would change the state of the components they connected with and affect the structure adversely.With the development of the cable structure and the cable material,the full lock coil strands had been widely used in the cable structure such as tensegrity structures.Study on the anti-sliding performance of the full lock coil strand-cable clamp became extremely necessary.This paper summarized specifications and research literatures on the anti-sliding performance of the cable clamps,and analyzed the different requirements of the anti-sliding performance of the cable clamps between domestic and foreign norms.This paper pointed out limitations of the existing research and improved the research methods.Furthermore,according to the research and engineering experience,the qualitative analysis of the factors affecting the anti-sliding performance of the cable clamps was conducted.It was pointed out that main direct influencing factors were effective tightening force of high-strength bolts,friction coefficient and tightening pressure distribution unevenness coefficient.The anti-sliding experiment of three full lock coil strand-cable clamps was designed and conducted in the background of stadium and natatorium in Suzhou Industrial Park Sports Center.The law of sliding displacement of the cable clamps and changement of tightening force of the high-strength bolts,the ultimate anti-sliding bearing capacity and the comprehensive friction coefficient were obtained.It was also found that the decrease of the cable diameter caused by the tension of the cable and radical compression creep was the main factor of the loss of the high-strength bolts' pre-tightening force,while the proportion of pre-tightening loss caused by the strain relaxation of the high strength bolts was small.Th e obvious time effect appeared in the loss of the high-strength bolts' pre-tightening force.The finite element analysis on the ultimate bearing capacity of the cable clamps applied in stadium and natatorium was carried out.By modifying the friction coefficient of the contact surface between strands and cable clamps,the ultimate bearing capacity of the cable clamps was basically the same as the experimental results.By contrast analysis,the cable clamps' sliding law of the analysis was consistent with the experimental results,the same as changing law of high-strength bolts' tightening force.The results above verified the accuracy of the finite element analysis.Taking the radical cable clamp of the stadium as the object of study,the parameters of the anti-sliding performance of the cable clamp were analyzed,such as pre-tightening force of high-strength bolts,friction coefficient and cable force.It was found that the ultimate bearing capacity of the cable clamp increased linearly with the increase of the pre-tightening force of high-strength bolts and friction coefficient,and decreased linearly with the increase of the cable force.It was also found that the tightening force of high-strength bolts decreased linearly with the increase of cable force.According to the characteristics of transversely isotropic materials,the analytic formula of the loss of high-strength bolts' pre-tightening force caused by the increase of cable force was deduced.According to the results of finite element analysis and experiment,the formulas,which considering the loss of high-strength bolts' pre-tightening force,for calculating the anti-sliding bearing capacity of the cable clamps,and the recommended values of each parameters were put forward.At last,the research contents and main achievements of this paper were summarized.The shortcomings of this paper were pointed out,and the future research on the anti-sliding performance of the cable clamps was also discussed.