The Complex Modal Analysis Of Stay Cables-tuned Mass Damper System

Cable-stayed bridge represents a major contemporary bridges largest span bridge, which span a large, spanning strong advantage is unmatched by other bridge. The main components of the cable tension with flexibility large and small stiffness, large elastic modulus and damping characteristics of small lead, with increasing length of the cable’s growth is also increasing the safety of the bridge had not ignored affected. Many engineering accident proof vibration control cable on the safe use of the bridge is very important. Currently try to take vibration add additional cable between the cable or cable viscous dampers to reduce the cable on the project, which has a mounting location is not too high, prone bridge coupled with vibration damping effect with the theoretical value of the difference between the larger issues. The topic for this problem, proposed the use of tuned mass damper(TMD) cable vibration suppression theoretical formula, designed to suppress TMD cable vibration model. Complex modal analysis method using a cable-stayed- tuned mass damper(C-TMD) vibration characteristics of the system, to get the effect of various parameters on the cable TMD damping. The actual cable with engineering background, proposed TMD design parameters different order of vibration suppression when the cable. This paper made the following research:1) To derive the theoretical formulas TMD single cable vibration suppression; due to gravity caused by cable sag and bending stiffness is small, so ignore its effects, taking into account the long cable tension, cable tension, cable mass per unit length, TMD quality, TMD damper, TMD damping ratio and other parameters on their cable systems and TMD composition, according to the principle of structural vibration, create a system vibration equation. Vibration equation of the system using numerical solution obtained equation system modal damping ratio; analysis performed six parameters, analysis parameters on the system modal damping ratio of a single TMD system modal equation; In the context of engineering example, be a single TMD system design, based on a specific length of cable, cable tension, mass per unit length of cable and other parameters to the system modal damping ratio value is constant, optimal design TMD quality, TMD damper, TMD self-damping ratio;2) Inhibition of a single cable-based TMD, in ignoring the cable sag due to gravity and flexural stiffness, considering both TMD simultaneously on a cable system, the cable tension long cable tension, nine parameters cable mass per unit length, two TMD mass, damping, damping ratio itself, both theoretical formulas are derived TMD cable vibration suppression, reuse numerical analysis method to obtain system modal damping ratio equation;3) Two TMD system modal parameter analysis equation, respectively discuss the impact of parameters on the system modal damping ratio; In the context of engineering examples, conducted two TMD design; given the premise of the system is the damping ratio for a particular cable length, cable tension, mass per unit length of cable parameters, the optimal design of the two TMD quality, TMD damping, TMD self-damping ratio.