Research On Bending Performance Of Cable

With the increase of the span and operational requirement of buildings and bridges,the prestressed steel structures are widely used in stadiums, stations, airport andlarge-scale public building etc. because of light quality, attractive appearance, highoverall stiffness and better structural performance. The control and monitoring ofcable force play an important role in the shape forming and safety of the structure, incurrent, the vibration frequency method is widely used to monitor the cable force. Butthe method is low accuracy because of many factors, research on these influencefactors must do in order to modify the cable force and the flexural rigidity is one ofthe factors. Analytical and experimental research on the flexural rigidity is done in thepaper.In the experiment, measuring the displacement in the middle-span and calculatingthe flexural rigidity through the formula as a simply supported beam loaded in themiddle of the beam. The length of the cable is1050mm and the span is816mm, thecable used in the experiment include semi-parallel wire strand, steel spiral strand,steel strand bundle and galfan-coated cable. Each type of cable is divided into threegroups: the groupⅠis the cable without any treatment, the groupⅡis the cable that thetwo end sections are welded as a whole respectively, the group Ⅲ is the cable withpretension. The flexural rigidity of the cable got from the experiment is betweenEⅠmaxand EⅠmin, and it can be calculated by k·EIreduced, where k is a reduction factor.For the cable without treatment, the value of the k is0.02~0.2in the first line segmentand0.01~0.04in the second line segment. For the end-welded cable, the value of thek is0.04~0.7in the first line segment and0.01~0.15in the second line segment. Forthe cable with pretension, the value of the k is0.2~0.8.Using Abaqus to analyze the factors affecting the bending performance of the cable.Establishing common contact between the wires and establishing the models of cablewith HDPE coating, cable with different friction coefficient, cable with different laylength, cable welded, cable with different layers and cable with pretension. Theconclusions of the analysis are shown as follows: the PE coating has certain protectiveeffect on the cable that the PE coating mainly bears the laterl load firstly and when itdestroyed, the wires bear the load; the wires slides under lateral load, the contact areasbetween the wires increase with the load; the flexural rigidity increases with theincrease of the friction coefficient and EI=1.454μ; the flexural rigidity increaseswith the increase of the lay length and Δ EI≈Δh; k decreases with the increase of thelayer; the flexural rigidity of the cable with end sections welded and with pretension islarger than the cable without treatment, and it is consistent with the experiment.