Design method and damper of a variable parameter multifunctional viscous damper

Abstract

The invention discloses a design method of a multi-functional variable-parameter viscous damper and the damper, and relates to the technical field of shock absorbing. The design method of the multi-functional variable-parameter viscous damper includes the steps that according to the damping factor C I and the speed factor alpha I, varying with the change of the speed V of a damper valve, of the viscous damper, a constitutive relation curve of the viscous damper is divided into a plurality of phases; according to the constitutive relation curve, three curved surfaces of the damper valve in the viscous damper are designed; and the first curved surface, the second curved surface and the third curved surface correspond to the phase I, the phase II, and the phase III. According to the design method, the viscous damper can automatically adjust damping force based on the movement speed of a damper piston, and meet requirements for a plurality of application scenarios in the same bridge. The viscous damper can effectively protect the bridge against damage caused by temperature-resulted deformation, is beneficial for reducing displacements caused by wind vibration and external loads of brakes so that devices, such as the viscous damper and expansion joints, can be prevented from premature fatigue and damage, and is beneficial for improving the seismic resistance of the bridge structure.

Description

technical field [0001] The invention relates to the technical field of vibration reduction, in particular to a design method of a multifunctional viscous damper with variable parameters and the damper. Background technique [0002] A common viscous damper is usually composed of a cylinder, a piston, a piston rod and a damping medium. The damping medium is filled in the two cavities at the front and rear of the piston. The piston rod and the piston can slide in the inner cavity of the cylinder. During the sliding process of the piston, the damping medium flows from one cavity to the other through the passage between the piston and the cylinder. body. [0003] Damping coefficient and velocity exponent are two important parameters reflecting the mechanical performance of viscous damper. A viscous damper with a small speed index will generate a large damping force at an extremely low speed. Taking the speed index of piston movement as 0.1 as an example, when the damping valve ...

AI Technical Summary

Problems solved by technology

A viscous damper with a small speed index will generate a large damping force at an extremely low speed. Taking the speed index of piston movement as 0.1 as an example, when the damping valve speed of the viscous damper is V=0.005V max , the damping force F corresponding to the viscous damper D =0.5887F D max , where V max and F D max are the maximum speed and maximum damping force of the viscous damper damper valve respectively. Under the action of strong temperature difference, long-span bridges are prone to strong nonlinear time-varying temperature difference effects, resulting in serious temperature-induced stress in the structure of long-span bridges Concentration and temperature-induced deformation cause serious structural damage; viscous dampers with small velocity exponents have a limited increase in damping force when the damping valve speed is high, which is not conducive to improving the seismic performance of the structure under strong earthquakes

If a viscous damper with a large velocity index is selected, the damping force increases slowly at low speeds, and the bridge may have a large displacement under the action of vehicle braking and slight wind vibration, resulting in viscous damping Structural components such as devices and expansion joints are prone to fatigue damage

It can be seen that the applicable scenarios of traditional fixed-parameter viscous dampers are relatively single. Generally, multiple viscous dampers of different specifications are used in cable-stayed bridges to solve the above problems. For example, Wuhan Tianxingzhou road-rail cable-stayed bridge Dual combined dampers are used. On the one hand, twelve 40-ton magneto-rheological dampers are used in the longitudinal direction of the bridge to limit the small vibration caused by braking. On the other hand, large-scale dampers with a maximum output of 200 tons are used to control the future earthquake and other loads of the main bridge. drift, which will inevitably increase the difficulty of construction and installation and the cost of the project

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