Method and system for predicting damping force of double-order viscous damper

Abstract

To provide a damping force prediction method and system for a double-order viscous damper.SOLUTION: The prediction method comprises the steps of: calculating only the pressure difference between the two ends of a primary piston in the first stage; calculating the pore damping force of the primary piston according to the pressure difference between the two ends of the first-stage primary piston as the damping force of the first-stage viscous damper; respectively calculating pressure differences at two ends of the primary piston and the secondary piston in the transition section and the second stage; calculating the damping force of the primary piston according to the pressure difference between the two ends of the primary piston, calculating the damping force of the secondary piston according to the pressure difference between the two ends of the secondary piston, and taking the sum of the pore damping force of the primary piston and the damping force of the secondary piston as the damping force of the viscous damper in the transition section or the second stage.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to the technical field of structural vibration damping control, and in particular to a method and system for predicting the damping force of a two-stage viscous damper. [Background technology]

[0002] Earthquakes are inevitable natural disasters for human society, and most of the casualties and economic losses caused by earthquakes are caused by the collapse of buildings. Therefore, passive control technology has been proposed in the field of architecture. Passive control technology mainly adopts two types of methods: energy dissipation and vibration reduction and vibration isolation. The energy dissipation and vibration reduction method is simple and reliable, so it has become one of the main means of earthquake-resistant design in modern society. The energy dissipation and vibration reduction method controls the dynamic response of building structures during earthquakes by introducing mechanical devices that can dissipate seismic energy, thereby achieving the function of protecting the main structural parts.

[0003] Viscous dampers are widely used dampers. The reciprocating motion of the piston in the damper causes high-viscosity fluid to pass through small holes on the piston and the gap with the cylinder at high speed under the action of pressure difference, generating damping. At the same time, as a hydraulic device, the viscous fluid damper has no additional stiffness in the low frequency range and is a velocity-dependent damper. A numerical analysis was carried out on the seismic response of a reinforced concrete frame adopting a viscous damper, and the presence of structural passive control succeeded in reducing the displacement of the top and lower floors.

[0004] However, the traditional single-stage viscous damper cannot meet the higher demand. At present, the structure of the viscous damper is modified to meet the demands of different working conditions. The structure and working mechanism of the two-stage viscous damper have already been put on the market.

[0005] The two-stage viscous damper mainly consists of a main cylinder, an auxiliary cylinder, a piston rod, a primary piston fixed to the piston rod, a secondary cylinder disposed between the main cylinder and the auxiliary cylinder, and a secondary piston fixed to the piston rod and disposed in the secondary cylinder, and both the primary piston and the secondary piston have damping holes. The movement of the piston rod makes the primary piston and the secondary piston move together, which changes the cross section of the inner wall of the secondary cylinder, and therefore the gap between the secondary piston and the inner wall of the secondary cylinder changes during the movement process, meeting the needs of different working states.

[0006] However, the existing calculation method for single-stage viscous dampers cannot be applied to two-stage viscous dampers, making it difficult to perform structural earthquake response analysis. Summary of the Invention

[0007] In order to solve the above problems, an embodiment of the present invention provides a method for predicting the damping force of a two-stage viscous damper. When a damper secondary piston of the two-stage viscous damper is in a first stage, the damping force includes a pore flow damping force of the primary piston. When the damper secondary piston is in a transition stage, the damping force includes a pore flow damping force of the primary piston, a gap flow and a pore flow damping force of the secondary piston, and the gap flow damping force of the secondary piston is related to the position and the motion speed of the secondary piston. After the damper secondary piston has completely entered the second stage, the damping force includes a pore flow damping force of the primary piston, a gap flow and a pore flow damping force of the secondary piston, and the gap flow damping force of the secondary piston is related to the motion speed of the secondary piston. The prediction method includes the steps of: in the first stage, acquiring a pore flow rate of the primary piston, and calculating a pressure difference between both ends of the primary piston in the first stage based on the pore flow rate of the primary piston; and calculating a pore damping force of the primary piston as a damping force of the viscous damper in the first stage based on the pressure difference between both ends of the primary piston in the first stage; or, in the transition stage and the second stage, acquiring a pore flow rate of the primary piston, a pore flow rate and a gap flow rate of the secondary piston, and calculating a pressure difference between both ends of the primary piston based on the pore flow rate of the primary piston, and calculating a pressure difference between both ends of the secondary piston based on a sum of the pore flow and gap flow rates of the secondary piston; calculating a damping force of the primary piston based on the pressure difference between both ends of the primary piston, calculating a damping force of the secondary piston based on the pressure difference between the both ends of the secondary piston, and setting the sum of the pore damping force of the primary piston and the damping force of the secondary piston as the damping force of the viscous damper in the transition stage or the second stage.

[0008] Optionally, the pore flow rate of the first stage primary piston is: JPEG2025029582000002.jpg16170, where m is the flow index, k is the consistency coefficient, l is the width of the piston, i.e., the length of the circular tube, s means that the piston has s sets of circular holes with different diameters, and R i is the radius of the i-th set of holes, and n i is the number of holes in the i-th set, Δp is the pressure difference when the fluid flows through a circular tube of length l, Q is the flow rate of the primary piston, Calculate the pressure difference across the first stage primary piston as: JPEG2025029582000003.jpg17170, where m is the flow index, k is the consistency coefficient, l is the width of the piston, i.e., the length of the circular tube, s means that the piston has s sets of circular holes with different diameters, and R i is the radius of the i-th set of holes, and ni is the number of holes in the i-th set, Δp is the pressure difference when the fluid flows through a circular tube of length l, Q is the flow rate of the primary piston, Calculate the pore damping force of the first stage primary piston as follows: JPEG2025029582000004.jpg10170where m is the flow index (attenuation index), k is the consistency coefficient, D0 is the diameter of the piston, d is the diameter of the piston rod, l is the width of the piston, and s means that the piston has s sets of round holes with different diameters, and d i is the diameter of the i-th set of holes, and n i is the number of the i-th set of round holes, x is the displacement of the piston, v is the moving speed of the piston, and S is the distance from the surface of the secondary piston to the displaced cross section of the inner wall of the secondary cylinder in the equilibrium stage.

[0009] Optionally, the pore flow and interstitial flow rates of the secondary piston during the transition phase are: JPEG2025029582000005.jpg18170, where m is the flow index, k is the consistency coefficient, D0 is the diameter of the piston, D is the inner diameter of the cylinder, and R i is the radius of the i-th set of holes, l is the width of the piston, s means that the piston has s sets of holes with different diameters, and n i is the number of the i-th set of round holes, x is the displacement of the piston, v is the speed of the piston, S is the distance from the surface of the secondary piston to the cross section of the inner wall of the secondary cylinder in the equilibrium stage, h is the height of the gap, Δp is the pressure difference between both ends of the secondary piston, Q is the flow rate, Calculate the pressure difference across the secondary piston during the transition phase as: JPEG2025029582000006.jpg24170, where m is the flow index, k is the consistency coefficient, D0 is the diameter of the piston, D is the inner diameter of the cylinder, and R iis the radius of the i-th set of holes, l is the width of the piston, s means that the piston has s sets of holes with different diameters, and n i is the number of the i-th set of round holes, x is the displacement of the piston, v is the moving speed of the piston, S is the distance from the surface of the secondary piston to the cross section of the inner wall of the secondary cylinder in the equilibrium stage, h is the height of the gap, Δp is the pressure difference between both ends of the secondary piston, Q is the flow rate, Calculate the damping force of the secondary piston as follows: JPEG2025029582000007.jpg29170The damping force in the transition phase is equal to the superposition of the damping forces of the primary and secondary pistons: JPEG2025029582000008.jpg35170JPEG2025029582000009.jpg13170Where m is the flow index, k is the consistency coefficient, D0 is the diameter of the piston, D is the inner diameter of the cylinder, and R i is the radius of the i-th set of holes, l is the width of the piston, d is the diameter of the piston rod, and d i is the diameter of the i-th set of holes, s means that the piston has s sets of holes with different diameters, and n i is the number of the i-th set of round holes, x is the piston displacement, v is the piston moving speed, S is the distance from the surface of the secondary piston to the cross section of the inner wall of the secondary cylinder at the equilibrium stage, h is the gap height, and Q is the flow rate.

[0010] Optionally, the pore flow and interstitial flow rates of the second stage secondary piston are: JPEG2025029582000010.jpg19170, where m is the flow index, k is the consistency coefficient, D0 is the diameter of the piston, D is the inner diameter of the cylinder, and R i is the radius of the i-th set of holes, l is the width of the piston, s means that the piston has s sets of holes with different diameters, and n iis the number of holes in the i-th set, v is the piston velocity, h is the gap height, Δp is the pressure difference across the secondary piston, Q is the flow rate, Calculate the pressure difference across the second stage secondary piston as: JPEG2025029582000011.jpg24170, where m is the flow index, k is the consistency coefficient, D0 is the diameter of the piston, D is the inner diameter of the cylinder, and R i is the radius of the i-th set of holes, l is the width of the piston, s means that the piston has s sets of holes with different diameters, and n i is the number of holes in the i-th set, v is the piston velocity, h is the gap height, Δp is the pressure difference across the secondary piston, Q is the flow rate, Calculate the damping force of the secondary piston in the second stage as: JPEG2025029582000012.jpg29170The damping force of the second stage is equal to the overlap of the primary and secondary pistons: JPEG2025029582000013.jpg29170JPEG2025029582000014.jpg13170Where m is the flow index, k is the consistency coefficient, D0 is the diameter of the piston, D is the inner diameter of the cylinder, and R i is the radius of the i-th set of holes, l is the width of the piston, d is the diameter of the piston rod, and d i is the diameter of the i-th set of holes, s means that the piston has s sets of holes with different diameters, and n i is the number of the i-th set of round holes, x is the piston displacement, v is the piston movement speed, S is the distance from the surface of the secondary piston to the cross section of the inner wall of the secondary cylinder at the equilibrium stage, h is the gap height, and Q is the flow rate.

[0011] Optionally, the prediction method further comprises: calculating a damping coefficient of each stage based on the damping force of the viscous damper of the first stage, the transition stage, or the second stage; The method further includes a step of designing component parameters for the two-stage viscous damper according to the damping coefficients of each stage and the seismic reduction design goal.

[0012] Optionally, the damping coefficient of each stage is: JPEG2025029582000015.jpg49170 Optionally, the step of performing component parameter design for the two-stage viscous damper according to the damping coefficient of each stage and the seismic reduction design goal includes determining a target damping coefficient and a target damping index based on the seismic reduction design goal, where the target damping coefficient includes a primary damping coefficient and a secondary damping coefficient, and performing component parameter design for the two-stage viscous damper based on the target damping coefficient and the target damping index.

[0013] Optionally, the features influencing the primary damping coefficient include a diameter and number of piston holes of the primary piston, a diameter of the primary piston, a width of the primary piston, a diameter of a piston rod, an inner diameter of the primary cylinder, a flow index and a consistency coefficient of the damping fluid. The features influencing the secondary damping coefficient include, in addition to the features of the primary piston, a diameter and number of piston holes of the secondary piston, a diameter of the secondary piston, a width of the secondary piston, a diameter of a piston rod, an inner diameter of the secondary cylinder, a distance between an inner wall of the secondary cylinder and the secondary piston, a flow index and a consistency coefficient of the damping fluid.

[0014] Optionally, the transition damping coefficient is further included, which in turn includes, in addition to the characteristics of the primary piston, the diameter and number of piston holes in the secondary piston, the diameter of the secondary piston, the width of the secondary piston, the diameter of the piston rod, the inner diameter of the secondary cylinder, the distance between the inner wall of the secondary cylinder and the secondary piston, the flow index and consistency coefficient of the damping liquid, and the relative displacement relationship between the secondary piston and the variable cross section of the secondary cylinder.

[0015] An embodiment of the present invention provides a prediction system for damping force of a two-stage viscous damper. When a damper secondary piston of the two-stage viscous damper is in a first stage, the damping force includes a pore flow damping force of a primary piston. When the damper secondary piston is in a transition stage, the damping force includes a pore flow damping force of a primary piston, a gap flow and a pore flow damping force of a secondary piston, and the gap flow damping force of the secondary piston is related to the position and the motion speed of the secondary piston. After the damper secondary piston has completely entered a second stage, the damping force includes a pore flow damping force of a primary piston, a gap flow and a pore flow damping force of a secondary piston, and the gap flow damping force of the secondary piston is related only to the motion speed of the secondary piston. The prediction system includes: A first damping force calculation module for obtaining a pore flow rate of the primary piston in the first stage, and calculating a pressure difference between both ends of the primary piston in the first stage based on the pore flow rate of the primary piston, and calculating a pore damping force of the primary piston as a damping force of the viscous damper in the first stage based on the pressure difference between both ends of the primary piston in the first stage; or The present invention further includes a second damping force calculation module for obtaining a pore flow rate of a primary piston and simultaneously obtaining a sum of a pore flow rate and a gap flow rate of a secondary piston in the transition stage and the second stage, calculating a pressure difference between both ends of the primary piston based on the pore flow rate of the primary piston, calculating a pressure difference between both ends of the secondary piston based on the sum of the pore flow and gap flow rate of the secondary piston, calculating a damping force of the primary piston based on the pressure difference between both ends of the primary piston, and calculating a damping force of the secondary piston based on the pressure difference between the both ends of the secondary piston, and setting the sum of the pore damping force of the primary piston and the damping force of the secondary piston as the damping force of the viscous damper in the transition stage or the second stage.

[0016] The method and system for predicting the damping force of a two-stage viscous damper provided by the embodiments of the present invention include methods for predicting the damping forces of the first stage, transition stage and second stage, which can effectively predict the damping force of a two-stage viscous damper, which is more accurate than the damping force calculated by the conventional calculation method that directly uses the superposition of the damping forces of viscous dampers, and can effectively perform structural seismic response analysis by adding a two-stage viscous damper. [Brief description of the drawings]

[0017] In order to more specifically describe the technical means in the embodiments of the present invention or the prior art, the drawings necessary for the description of the embodiments or the prior art will be briefly described below. Of course, the drawings in the following description are only the embodiments of the present application, and those skilled in the art can obtain other drawings based on the drawings provided without creative labor.

[0018] [Figure 1] FIG. 2 is a cross-sectional schematic diagram of a two-stage viscous damper provided in an embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic cross-sectional view of a secondary piston of a two-stage viscous damper according to an embodiment of the present invention. [Diagram 3] FIG. 2 is a schematic flow diagram of a method for predicting the damping force of a two-stage viscous damper in an embodiment of the present invention. [Figure 4] FIG. 2 is a schematic diagram of the first stage of secondary piston movement of the two-stage viscous damper in an embodiment of the present invention. [Diagram 5] 4 is a schematic diagram of a transition stage of secondary piston movement of a two-stage viscous damper in an embodiment of the present invention. FIG. [Figure 6] FIG. 13 is a schematic diagram of the second stage of secondary piston movement of the two-stage viscous damper in accordance with an embodiment of the present invention. [Figure 7] FIG. 11 is a schematic flow diagram of a method for predicting the damping force of another two-stage viscous damper in an embodiment of the present invention. [Figure 8] 1 is a damping force-displacement hysteresis curve of a two-stage viscous damper in an embodiment of the present invention. [Figure 9]FIG. 2 is a structural schematic diagram of the damping force prediction system of a two-stage viscous damper provided by an embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] In order to make the above objects, features and advantages of the present invention more comprehensible, the following detailed description will be given of specific embodiments of the present invention with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are used for the interpretation of the present invention, and are not intended to limit the present invention.

[0020] A conventional single-stage viscous damper structure consists of a cylinder, a piston, a viscous fluid, and a piston rod. The cylinder is filled with viscous fluid. The piston can reciprocate within the cylinder by driving the piston rod. The piston has an appropriate number of small holes. When the cylinder and the piston move relative to each other due to deformation of the structure, the viscous fluid flows through the small holes under the action of pressure difference, generating a damping force, and dissipating the vibration energy through viscous energy consumption, thereby achieving the purpose of energy dissipation and vibration reduction.

[0021] Currently, the mechanical formula for the conventional single-stage viscous damper is: F=Cν α In the formula, the damping index is mainly obtained from the properties of the damping fluid. Regarding the performance parameter of the damping coefficient C, there is currently a calculation method for the porous viscous damper, which can be further designed and processed for production. JPEG2025029582000016.jpg14170However, the traditional single-stage viscous damper cannot meet higher demands. In this case, the structure of the viscous damper needs to be modified to meet the demands of different working conditions. At present, the structure and working mechanism of the two-stage viscous damper have already been put on the market.

[0022] The two-stage viscous damper mainly consists of a main cylinder, a sub cylinder, a piston rod, a primary piston fixed to the piston rod, a secondary cylinder disposed between the main cylinder and the sub cylinder, and a secondary piston fixed to the piston rod and disposed in the secondary cylinder, and both the primary piston and the secondary piston have a damping hole. The movement of the piston rod makes the primary piston and the secondary piston move together, and the cross section of the inner wall of the secondary cylinder changes, so that the gap between the secondary piston and the inner wall of the secondary cylinder changes during the movement to meet the demands of different working states. In the cross-sectional schematic diagram of the two-stage viscous damper shown in Figure 1, the main cylinder 1, the primary piston 2, the secondary cylinder 3, the secondary piston 4 and the piston hole 5 are shown.

[0023] However, such two-stage viscous dampers still have some problems to solve: (1) It is difficult to perform structural earthquake response analysis due to the lack of a restoring force model for the two-stage viscous damper. (2) Due to the lack of calculation theory for the performance parameters of the two-stage viscous damper, it is difficult to carry out detailed design of the viscous damper for its performance parameters.

[0024] The embodiments of the present invention aim to solve the technical problems existing in the prior art, namely, the lack of a restoration force model for a two-stage viscous fluid damper (VFD), which makes it difficult to perform structural earthquake response analysis, and the lack of a calculation theory for the performance parameters of a two-stage VFD, which makes it difficult to perform detailed design of the VFD with respect to its performance parameters.

[0025] First, the first problem (the calculation formula for the damping force of the two-stage viscous damper is unclear, and the damping force of the variable damping viscous damper cannot be obtained relatively accurately based on the damper structure) is addressed. The embodiment of the present invention provides a method for predicting the damping force of the two-stage viscous damper, establishes a restoring force model of the two-stage viscous damper, solves the problems related to the research of the mechanical performance of the two-stage viscous damper, and can effectively predict the output magnitude of the damping force of the two-stage viscous damper. It is suitable for various energy dissipation and seismic reduction structural systems.

[0026] Next, regarding the second problem, the embodiment of the present invention proposes a calculation theory for the performance parameters of a two-stage viscous damper, and the two-stage viscous damper can be designed in detail based on the performance parameters of the viscous damper required for the structure to be constructed in order to adapt to the performance demands of energy dissipation and seismic reduction at various stress stages of the building structure.

[0027] According to the structural features of the two-stage viscous damper, the embodiment of the present invention can calculate the damping force when the damper is in different working states. The working state of the two-stage viscous damper is determined by two parts: the first part is the moving speed of the piston, and the second part is the position of the piston. The calculations assume the following: When the damper secondary piston is in the first stage, there is only the pore flow damping force of the primary piston. When the secondary piston is in the transition stage, that is, when the secondary piston starts and completely enters the second stage, the damping force not only has the pore flow damping force of the primary piston, but also includes the gap flow and pore flow damping of the secondary piston. At this time, the gap flow length of the secondary piston changes, so the damping force of the secondary piston also changes, which is related to the position and movement speed of the piston. After the secondary piston completely enters the second stage, there is also the pore flow damping force of the primary piston, and there is also the gap flow and pore flow damping of the secondary piston. After completely entering the second stage, the gap length between the secondary piston and the cylinder no longer changes, and in this case, the damping force of the secondary piston is only related to the movement speed of the piston.

[0028] In the schematic cross-sectional view of the two-stage viscous damper secondary piston shown in FIG. 2, a cylinder 11, a piston 12, and a piston rod 13 are shown. In FIG. 2, the diameter D0 of the piston, the inner diameter D of the cylinder, the diameter d of the piston rod, the height h of the gap, and the diameter d of the small hole are shown. i is also shown.

[0029] Please refer to the flow diagram of the method for predicting the damping force of the two-stage viscous damper in the embodiment of the present invention shown in FIG. 3. In the two-stage viscous damper to which this method is applied, when the damper secondary piston is in the first stage, the damping force includes the pore flow damping force of the primary piston. When the damper secondary piston is in the transition stage, the damping force includes the pore flow damping force of the primary piston, the gap flow and pore flow damping force of the secondary piston. The gap flow damping force of the secondary piston is related to the position and the movement speed of the secondary piston. After the damper secondary piston has completely entered the second stage, the damping force includes the pore flow damping force of the primary piston, the gap flow and pore flow damping force of the secondary piston, and after completely entering the second stage, the gap flow damping force of the secondary piston is only related to the movement speed of the secondary piston. This method includes the following steps S302 to S308. In S302, in the first stage, a pore flow rate of the primary piston is obtained, and a pressure difference across the primary piston in the first stage is calculated based on the pore flow rate of the primary piston.

[0030] In S304, the pore damping force of the primary piston is calculated as the damping force of the first-stage viscous damper based on the pressure difference between both ends of the primary piston in the first stage.

[0031] In this embodiment, a method for predicting the first stage damping force based on the above method is provided.

[0032] In S306, in the transition stage and the second stage, the pore flow rate of the primary piston and the sum of the pore flow rate and the gap flow rate of the secondary piston are obtained, and the pressure difference between both ends of the primary piston is calculated based on the pore flow rate of the primary piston, and the pressure difference between both ends of the secondary piston is calculated based on the sum of the pore flow rate and the gap flow rate of the secondary piston.

[0033] In S308, the damping force of the primary piston is calculated based on the pressure difference between both ends of the primary piston, and the damping force of the secondary piston is calculated based on the pressure difference between both ends of the secondary piston, and the sum of the pore damping force of the primary piston and the damping force of the secondary piston is regarded as the damping force of the viscous damper in the transition stage or the second stage.

[0034] In this embodiment, a method for predicting the damping forces in the transition stage and the second stage based on the above method is provided.

[0035] The method for predicting the damping force of a two-stage viscous damper provided by the embodiment of the present invention includes methods for predicting the damping force of the first stage, the transition stage and the second stage, which can effectively predict the damping force of a two-stage viscous damper, and is more accurate than the damping force calculated by the conventional calculation method that directly uses the superposition of the damping forces of viscous dampers, and can effectively carry out structural seismic response analysis by adding a two-stage viscous damper.

[0036] The implementation method and calculation process are described in detail below.

[0037] (1) When |x|≦S, the viscous damper only operates in the first stage, and there is only the pore damping output of the primary piston, and the secondary piston has zero damping force because the gap is too large. Figure 4 shows a schematic diagram of the first stage of the secondary piston movement of the two-stage viscous damper in an embodiment of the present invention. In Figure 4, the width l of the piston, the distance S from the surface of the secondary piston to the cross section of the inner wall of the secondary cylinder in the equilibrium stage, and the height h of the gap are shown.

[0038] Determine the pore flow rate of the first stage primary piston, including: There is only a pore flow rate for the primary piston: JPEG2025029582000017.jpg16170Where: m is the flow index (decay index), k is the consistency coefficient, l is the width of the piston, i.e., the length of the circular tube (round hole), s means that the piston has s sets of round holes with different diameters, and R i is the radius of the i-th set of holes, and n i is the number of holes in the i-th set, Δp is the pressure difference as the fluid flows through a circular tube of length l, and Q is the flow rate of the primary piston. Find the pressure difference across the first stage primary piston, including: Pressure difference across the primary piston: JPEG2025029582000018.jpg18170Where: m is the flow index (decay index), k is the consistency coefficient, l is the width of the piston, i.e., the length of the circular tube (round hole), s means that the piston has s sets of round holes with different diameters, R i is the radius of the i-th set of holes, and n i is the number of holes in the i-th set, Δp is the pressure difference as the fluid flows through a circular tube of length l, and Q is the flow rate of the primary piston. Find the damping force of the first stage viscous damper, i.e. the pore damping force of the primary piston, including: JPEG2025029582000019.jpg23170Pore flow damping force in the first stage: JPEG2025029582000020.jpg10170Where: m is the flow index (decay index), k is the consistency coefficient, D0 is the diameter of the piston, d is the diameter of the piston rod, l is the width of the piston, and s means that the piston has s sets of round holes with different diameters, and d i is the diameter of the i-th set of holes, and n i is the number of the i-th set of round holes, x is the displacement of the piston, v is the moving speed of the piston, and S is the distance from the surface of the secondary piston to the displaced cross section of the inner wall of the secondary cylinder in the equilibrium stage. (2) When S≦|x|≦l+S, the secondary piston is in the transition stage. At this time, the primary piston and the secondary piston of the viscous damper work together, and the secondary piston has both pore damping power and gap damping power. Figure 5 shows a schematic diagram of the transition stage of the secondary piston movement of the two-stage viscous damper in an embodiment of the present invention.

[0039] Determine the pore flow rate and interstitial flow rate of the secondary piston during the transition phase, including: The primary piston has only pore flow damping. The secondary piston has both pore flow damping and gap flow damping. Secondary piston flow rate (superposition of pore and interstitial flow rates): JPEG2025029582000021.jpg18170Where: m is the flow index (decay index), k is the consistency coefficient, D0 is the piston diameter, D is the cylinder inner diameter, and R i is the radius of the i-th set of holes, l is the width of the piston, s means that the piston has s sets of holes with different diameters, and n i is the number of the i-th set of round holes, x is the displacement of the piston, v is the speed of the piston, S is the distance from the surface of the secondary piston to the cross section of the inner wall of the secondary cylinder in the equilibrium stage, h is the height of the gap, Δp is the pressure difference between both ends of the secondary piston, Q is the flow rate, Find the pressure difference across the secondary piston during the transition phase, including: Pressure difference across the secondary piston: JPEG2025029582000022.jpg24170Where: m is the flow index (decay index), k is the consistency coefficient, D0 is the piston diameter, D is the cylinder inner diameter, and R i is the radius of the i-th set of holes, l is the width of the piston, s means that the piston has s sets of holes with different diameters, and n iis the number of the i-th set of round holes, x is the displacement of the piston, v is the speed of the piston, S is the distance from the surface of the secondary piston to the cross section of the inner wall of the secondary cylinder in the equilibrium stage, h is the height of the gap, Δp is the pressure difference between both ends of the secondary piston, Q is the flow rate, Determine the damping force of the viscous damper during the transition phase, i.e. the superposition of the damping forces of the primary and secondary pistons, including: Secondary piston damping force: JPEG2025029582000023.jpg31170The damping force in the transition phase is equal to the superposition of the primary and secondary pistons: JPEG2025029582000024.jpg37170JPEG2025029582000025.jpg14170Where: m is the flow index (decay index), k is the consistency coefficient, D0 is the piston diameter, D is the cylinder inner diameter, and R i is the radius of the i-th set of holes, l is the width of the piston, d is the diameter of the piston rod, and d i is the diameter of the i-th set of holes, s means that the piston has s sets of holes with different diameters, and n i is the number of the i-th set of round holes, x is the piston displacement, v is the piston movement speed, S is the distance from the surface of the secondary piston to the cross section of the inner wall of the secondary cylinder at the equilibrium stage, h is the gap height, and Q is the flow rate. (3) When |x|≧l+S, it is indicated that the viscous damper is fully in the second stage of operation. At this time, the primary piston and the secondary piston of the viscous damper work together, and the secondary piston has both pore damping output and gap damping output. Figure 6 shows a schematic diagram of the second stage of the secondary piston movement of the two-stage viscous damper in an embodiment of the present invention. Here, x is the displacement of the piston of the damper, l is the width of the piston of the damper, and S is the distance from the surface of the secondary piston to the cross section of the inner wall of the secondary cylinder in the equilibrium stage.

[0040] Find the sum of the pore flow rate of the primary piston and the pore and interstitial flow rates of the secondary piston in the second stage, including: The primary piston only has pore flow damping force, the secondary piston has both pore flow and gap flow. At this time, the secondary piston has already completely entered the second stage, so the gap length does not change.

[0041] Secondary piston flow rate (superimposition of pore and interstitial flow): JPEG2025029582000026.jpg18170Where: m is the flow index (decay index), k is the consistency coefficient, D0 is the piston diameter, D is the cylinder inner diameter, and R i is the radius of the i-th set of holes, l is the width of the piston, s means that the piston has s sets of holes with different diameters, and n i is the number of holes in the i-th set, v is the speed of piston movement, h is the gap height, Δp is the pressure difference across the secondary piston, and Q is the flow rate. Find the pressure difference across the primary piston and the pressure difference across the secondary piston in the second stage, including: Pressure difference across the secondary piston: JPEG2025029582000027.jpg24170Where: m is the flow index (decay index), k is the consistency coefficient, D0 is the piston diameter, D is the cylinder inner diameter, and R i is the radius of the i-th set of holes, l is the width of the piston, s means that the piston has s sets of holes with different diameters, and n i is the number of holes in the i-th set, v is the speed of piston movement, h is the gap height, Δp is the pressure difference across the secondary piston, and Q is the flow rate. Find the damping force of the second stage viscous damper, i.e. the superposition of the damping forces of the primary and secondary pistons, including: The primary piston has only pore flow damping force, the secondary piston has both pore flow and gap flow.

[0042] At this point, the secondary piston has already fully entered the second stage, so the length of the gap no longer changes.

[0043] Secondary piston damping force: JPEG2025029582000028.jpg31170The damping force of the second stage is equal to the superposition of the primary and secondary pistons. JPEG2025029582000029.jpg31170JPEG2025029582000030.jpg13170Where: m is the flow index (decay index), k is the consistency coefficient, D0 is the piston diameter, D is the cylinder inner diameter, and R i is the radius of the i-th set of holes, l is the width of the piston, d is the diameter of the piston rod, and d i is the diameter of the i-th set of holes, s means that the piston has s sets of holes with different diameters, and n i is the number of holes in the i-th set, x is the displacement of the piston, v is the speed of the piston, S is the displacement from the surface of the piston to the point where the cross section of the secondary cylinder changes, h is the height of the gap, and Q is the flow rate.

[0044] FIG. 7 shows a schematic flow diagram of a method for predicting the damping force of a two-stage viscous damper in an embodiment of the present invention, which includes the following steps: 1. Enter the piston displacement and velocity. 2. Determine the condition of the piston.

[0045] If |x|≦S, 3. Calculate the flow rate of the viscous fluid in the first stage. 4. Calculate the pressure difference across the primary piston in the first stage. 5. Calculate the damping force of the viscous damper in the first stage. If S ≦ |x| ≦ l + S, 6. Calculate the flow rate of the viscous fluid during the transition stage. 7. Calculate the pressure difference across the piston during the transition stage. 8. Calculate the damping force of the viscous damper during the transition stage. If |x| ≧ l+S, 9. Calculate the viscous fluid flow rate for the second stage. 10. Calculate the pressure difference across the piston for the second stage. 11. Calculate the damping force of the viscous damper for the second stage.

[0046] The embodiment of the present invention proposes a method for predicting the damping force of a two-stage viscous damper and its restoring force model, and proposes a calculation theory for the performance parameters of the two-stage viscous damper. In order to meet the performance demands of energy dissipation and seismic reduction at various stress stages of the building structure, the two-stage viscous damper can be designed in detail based on the performance parameters of the viscous damper required for the structure to be built. The calculation formula for the damping force is as follows: JPEG2025029582000031.jpg56170The relationship between the damping force of the damper and the damping parameters can be simplified as follows: F=Cν α This results in the damping coefficients for the three stages being: JPEG2025029582000032.jpg54170From this, the two-stage viscous damper can be designed in detail based on the required performance parameters.

[0047] The features and performance of the embodiments of the present invention are described in more detail below with reference to examples. For example, we have a sinusoidal displacement x = A sin(2πft), where x is the sinusoidal displacement amplitude, f is the sinusoidal frequency, and t is the load time. max is greater than the displacement when the two-stage is fully started, that is, x≧l+S. At this time, the first stage, transition stage and second stage of the two-stage viscous damper are all activated by the sinusoidal displacement load. It is necessary to predict the damping forces of the two-stage viscous damper in these three parts.

[0048] In response to the above problems, the present embodiment provides a method for predicting the damping force of a two-stage viscous damper. Based on the structural characteristics of the two-stage viscous damper seismic isolation device, the damping force can be predicted relatively accurately, consistent with the actual situation, and the data is accurate and available.

[0049] First, this method requires you to enter a condition like this: Sine wave displacement x=A sin(2πft), unit: mm Corresponding speed ν=2πfA cos(2πft), unit: millimeters / second Flow index (decay index) m Consistency factor k, unit: Pascal-second Piston diameter D0, in millimeters Cylinder inner diameter D, unit: mm Piston rod diameter d, in mm Piston width l, in mm The number of sets of holes in the piston, s Diameter d of the i-th set of circular holes i , unit: mm Radius R of the i-th set of circular holes i , unit: mm Number of holes in the i-th set, n i , Distance S from the surface of the secondary piston to the cross section of the inner wall of the secondary cylinder in the equilibrium stage, unit: mm Gap height h, in mm The method for predicting the damping force of a two-stage viscous damper specifically includes the following steps 1 to 4. In step 1, input the sinusoidal displacement x = A sin(2πft), where x is the sinusoidal displacement amplitude, f is the sinusoidal frequency, and t is the load time. In step 2, obtain the velocity v, v = 2πfA cos(2πft), for each step based on the sinusoidal displacement. In step 3, the damping force of each stage is calculated according to the damping force prediction formula for the two-stage viscous damper. JPEG2025029582000033.jpg51170 In step 4, the damping force and the displacement at each step are plotted as a damping force-displacement curve based on the damping force obtained by adding a sinusoidal displacement. Figure 8 shows the damping force-displacement hysteresis curve of the two-stage viscous damper in the embodiment of the present invention.

[0050] Regarding the problem that there is a lack of calculation theory for the performance parameters of the two-stage viscous damper and it is difficult to carry out detailed design of the viscous damper for the performance parameters of the viscous damper, a corresponding analysis and design step is proposed. In the present invention, the damping coefficient and damping index can be designed and calculated through the structure of the damper, where the damping index can be determined through a rheological experiment of the damping liquid.

[0051] For example, for a certain building structure, it is necessary to select an appropriate two-stage viscous damper and carry out seismic reduction design and reinforcement for it. It is necessary to obtain the performance parameters of the two-stage viscous damper and design its structure in detail to facilitate the subsequent production processing of the two-stage viscous damper.

[0052] The specific design steps are as follows: Step 1: Use structural design software or manual calculation to design the main structure and establish a seismic model. According to the regional defense objectives, combine earthquake effects with other load effects, and take into account the seismic adjustment coefficient of bearing capacity to design the member cross-sections. At the same time, adopt corresponding seismic structural measures to ensure the ductility, deformation capacity, and energy dissipation capacity of the structure. Limit the structural elastic-plastic story displacement angle during a large earthquake. If traditional seismic resistance does not meet the demand, carry out seismic reduction design.

[0053] Step 2: According to the required seismic design target of the main structure, the damping coefficient and damping exponent (C1, C2, α) of the two-stage viscous damper required to reach the seismic design target are determined. According to the seismic model and the structural seismic isolation design needs, the two-stage viscous damper is defined and positioned in the structural analysis software, and the existing two-stage viscous damper subprogram is used to adjust the values ​​of the primary damping coefficient C1, secondary damping coefficient C2 and damping exponent α, and an earthquake response control analysis is performed on the seismic isolation structure to ensure that the story displacement angle and floor acceleration meet the design specifications.

[0054] Step 3: According to this proposal, design the component parameters of the two-stage viscous damper for the required performance parameters of the two-stage viscous damper.

[0055] Based on the performance parameters of the two-stage viscous damper obtained in step 2, the two-stage viscous damper is designed in detail according to the present proposal, that is, its components are designed, and appropriate damping fluid is selected to obtain the performance parameters required for the design. As a result, the structural seismic isolation design goal is achieved. In the specific design process, the influence of the component parameters of the two-stage viscous damper on its performance parameters is as follows: The damping coefficients for the different stages are: JPEG2025029582000034.jpg54170In this embodiment, the structural parameters of the two pistons do not need to be the same. In this way, by adjusting the structural characteristics of the two pistons in the same stage, the characteristic of the different damping forces of the primary piston and the secondary piston, that is, the characteristic of C2 / C1, can be achieved, so that the two-stage viscous damper can better dissipate seismic energy during a large earthquake and achieve the design goal.

[0056] C1, C2, and α are the main performance parameters that affect the performance of the two-stage viscous damper. C1, C2, and α can be determined based on the structural features of the two-stage viscous damper and the properties of the damping fluid. Through the combination of the values ​​of various parameters, the mechanical performance parameters of the damper can be obtained to realize the two-stage viscous damper required for the seismic isolation structure of the building.

[0057] The main features that affect C1 include the diameter and number of piston holes in the primary piston, the diameter of the primary piston, the width of the primary piston, the diameter of the piston rod, the inner diameter of the main cylinder, the flow index m and the consistency coefficient k of the damping fluid. In addition to the characteristics of the primary piston, the main characteristics that affect C2 also include the diameter and number of the piston holes of the secondary piston, the diameter of the secondary piston, the width of the secondary piston, the diameter of the piston rod, the inner diameter of the secondary cylinder, the distance between the inner wall of the secondary cylinder and the secondary piston, the flow index m and the consistency coefficient k of the damping fluid. C 移行is also a performance parameter that affects the two-stage viscous damper, and further optimization of the damping force prediction calculation method of the two-stage viscous damper. 移行 In addition to the characteristics of the primary piston, the main features that affect the displacement also include the diameter and number of the piston holes of the secondary piston, the diameter of the secondary piston, the width of the secondary piston, the diameter of the piston rod, the inner diameter of the secondary cylinder, the distance between the inner wall of the secondary cylinder and the secondary piston, the flow index m and the consistency coefficient k of the damping fluid. At the same time, the relative displacement relationship between the secondary piston and the displacement cross section of the secondary cylinder is also an important discriminant index.

[0058] At present, existing calculation software cannot perform specific analytical calculations for two-stage viscous dampers, and cannot predict the working state of the damper, the damper's speed, displacement, output and its relationship with its own structure. Using this method, the working state of the two-stage viscous damper, the damper's speed, displacement, output and its relationship with its own structure can be calculated more accurately.

[0059] At the same time, the damping coefficients C1, C2 of different working stages can be calculated more accurately, which makes it convenient for subsequent selection, design and test verification of the two-stage viscous damper in the context of building structure.

[0060] The embodiment of the present invention proposes a calculation method for a two-stage viscous damper, which improves the design process of the damper vibration reduction device and can predict the magnitude of the damping force according to the damper structure. Since the method takes into account the accuracy of the manufacturing process, the calculated damping force is more accurate than the conventional calculation method that directly uses the superposition of the damping force of the viscous damper. The working process of the two-stage viscous damper and the damping force-displacement hysteresis curve under the changes of the piston speed and various positions can be effectively simulated. The calculation method of the damping force of the two-stage viscous damper is optimized.

[0061] In summary, this proposal effectively solves two technical problems of the two-stage viscous damper, including the following (1) and (2): (1) A restoration force model of the two-stage viscous damper is proposed, which can effectively carry out the structural seismic response analysis of adding the two-stage viscous damper; (2) A calculation theory of the performance parameters of the two-stage viscous damper is proposed, which is favorable for the detailed design of the viscous damper for the performance parameters of the two-stage viscous damper.

[0062] Compared with conventional viscous damper calculation methods, the method for predicting the damping force of a two-stage viscous damper according to an embodiment of the present invention can relatively accurately predict the damping force of a viscous damper at different piston displacements and speeds when the structure experiences different types and levels of disasters.

[0063] In a two-stage viscous damper, a piston rod moves a piston under a displacement load. Theoretically, the two-stage viscous damper is two gap dampers connected in series, but an error occurs in the transition from the first stage to the second stage, and the actual damping force is smaller than the theoretical value. In order to minimize the effect of this error on the theoretical calculation, the present invention analyzes this error and optimizes the calculation method of the damping force of the two-stage viscous damper.

[0064] The embodiments of the present invention propose a restoration force model of a two-stage viscous damper, which can effectively carry out structural seismic response analysis by adding a two-stage viscous damper, and propose a calculation theory for the performance parameters of the two-stage viscous damper, which is advantageous for detailed design of the viscous damper based on the performance parameters of the two-stage viscous damper.

[0065] FIG. 9 shows a structural schematic diagram of a system for predicting damping force of a two-stage viscous damper provided by an embodiment of the present invention. The system includes: A first damping force calculation module 901 for obtaining a pore flow rate of the primary piston in the first stage, and calculating a pressure difference between both ends of the primary piston in the first stage based on the pore flow rate of the primary piston, and calculating a pore damping force of the primary piston as a damping force of the viscous damper in the first stage based on the pressure difference between both ends of the primary piston in the first stage; or The present invention includes a second damping force calculation module 902 for obtaining a pore flow rate of a primary piston, obtaining a pore flow rate and a gap flow rate of a secondary piston, calculating a pressure difference between both ends of the primary piston based on the pore flow rate of the primary piston, calculating a pressure difference between both ends of the secondary piston based on a sum of the pore flow and gap flow rates of the secondary piston, calculating a damping force of the primary piston based on the pressure difference between both ends of the primary piston, and calculating a damping force of the secondary piston based on the pressure difference between the both ends of the secondary piston, and setting the sum of the pore damping force of the primary piston and the damping force of the secondary piston as the damping force of the viscous damper in the transition stage or the second stage.

[0066] The damping force prediction system of a two-stage viscous damper provided by the embodiment of the present invention can predict the damping forces of the first stage, transition stage and second stage, and can effectively predict the damping force of a two-stage viscous damper. Compared with the conventional calculation method that directly uses the superposition of the damping forces of viscous dampers, the damping force obtained by calculation is more accurate, and structural seismic response analysis that adds a two-stage viscous damper can be effectively carried out.

[0067] Those skilled in the art can understand that the implementation of all or part of the steps in the above-mentioned embodiments can be completed by instructing a control device through a computer program, and the program can be stored in a computer-readable storage medium. The program can include the steps of the embodiments of the above-mentioned methods when executed, and the storage medium can be a memory, a magnetic disk, an optical disk, etc.

[0068] As used herein, relational terms such as first, second, etc. are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that such an actual relationship or sequence exists between those entities or operations. Also, the terms "comprise," "include," or any other variation thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that includes a set of elements includes not only those elements, but also other elements not expressly listed or that are inherent in such process, method, article, or apparatus. Absent more limitations, an element qualified by the phrase "comprise" does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. In each embodiment of the present specification, the description will be step-by-step, and the differences from other embodiments will be focused on. The same or similar parts between the embodiments may be referred to each other.

[0069] The above description of the disclosed embodiments enables one skilled in the art to realize or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art. The general principles defined herein may be embodied in other embodiments without departing from the spirit or scope of the present invention. Thus, the present invention is not limited to the embodiments disclosed herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for predicting damping force of a two-stage viscous damper, wherein when a damper secondary piston of the two-stage viscous damper is in a first stage, the damping force includes a pore flow damping force of a primary piston, and when the damper secondary piston is in a transition stage, the damping force includes a pore flow damping force of a primary piston, a gap flow and a pore flow damping force of a secondary piston, and the gap flow damping force of the secondary piston is related to a position and a moving speed of the secondary piston, and after the damper secondary piston has completely entered a second stage, the damping force includes a pore flow damping force of a primary piston, a gap flow and a pore flow damping force of a ... gap flow damping force of the secondary piston is related only to a moving speed of the secondary piston, The prediction method includes: obtaining a pore flow rate of a primary piston in the first stage and calculating a pressure difference across the primary piston in the first stage based on the pore flow rate of the primary piston; calculating a pore damping force of the primary piston as a damping force of a first stage viscous damper based on a pressure difference across the first stage primary piston; or In the transition stage and the second stage, a pore flow rate of a primary piston, a pore flow rate of a secondary piston and a gap flow rate of a secondary piston are obtained, and a pressure difference between both ends of the primary piston is calculated based on the pore flow rate of the primary piston, and a pressure difference between both ends of the secondary piston is calculated based on the sum of the pore flow rate and the gap flow rate of the secondary piston; calculating a damping force of a primary piston based on a pressure difference across both ends of the primary piston, calculating a damping force of a secondary piston based on a pressure difference across both ends of the secondary piston, and setting the sum of the pore damping force of the primary piston and the damping force of the secondary piston as the damping force of a viscous damper in the transition stage or the second stage.

2. The pore flow rate of the first stage primary piston is: Here, m is the flow index, k is the consistency coefficient, l is the width of the piston, i.e., the length of the circular tube, s means that the piston has s sets of circular holes with different diameters, and R ｉ is the radius of the i-th set of circular holes, and n ｉ is the number of holes in the i-th set, Δp is the pressure difference when the fluid flows through a circular tube of length l, Q is the flow rate of the primary piston, Calculate the pressure differential across the first stage primary piston as follows: Here, m is the flow index, k is the consistency coefficient, l is the width of the piston, i.e., the length of the circular tube, s means that the piston has s sets of circular holes with different diameters, and R ｉ is the radius of the i-th set of circular holes, and n ｉ is the number of holes in the i-th set, Δp is the pressure difference when the fluid flows through a circular tube of length l, Q is the flow rate of the primary piston, Calculate the pore damping force of the first stage primary piston as follows: where m is the flow index (decay index), k is the consistency coefficient, and D ０ is the diameter of the piston, d is the diameter of the piston rod, l is the width of the piston, s means that the piston has s sets of round holes with different diameters, and d ｉ is the diameter of the i-th set of circular holes, and n ｉ 2. The method of claim 1, wherein i is the number of the i-th set of holes, x is the displacement of the piston, v is the moving speed of the piston, and S is the distance from the surface of the secondary piston to the cross-section of the inner wall of the secondary cylinder in the equilibrium stage.

3. The pore flow and gap flow rates of the secondary piston in the transition stage are as follows: where m is the flow index, k is the consistency coefficient, and D ０ is the diameter of the piston, D is the inner diameter of the cylinder, and R ｉ is the radius of the i-th set of holes, l is the width of the piston, s means that the piston has s sets of holes with different diameters, and n ｉ is the number of the i-th set of holes, x is the displacement of the piston, v is the speed of the piston, S is the distance from the surface of the secondary piston to the cross section of the inner wall of the secondary cylinder in the equilibrium stage, h is the height of the gap, Δp is the pressure difference between both ends of the secondary piston, and Q is the flow rate. Calculate the pressure difference across the secondary piston during the transition phase as: where m is the flow index, k is the consistency coefficient, and D ０ is the diameter of the piston, D is the inner diameter of the cylinder, and R ｉ is the radius of the i-th set of holes, l is the width of the piston, s means that the piston has s sets of holes with different diameters, and n ｉ is the number of the i-th set of holes, x is the displacement of the piston, v is the speed of the piston, S is the distance from the surface of the secondary piston to the cross section of the inner wall of the secondary cylinder in the equilibrium stage, h is the height of the gap, Δp is the pressure difference between both ends of the secondary piston, and Q is the flow rate. Calculate the damping force of the secondary piston as follows: The damping force in the transition phase is equal to the superposition of the damping forces of the primary and secondary pistons: where m is the flow index, k is the consistency coefficient, and D ０ is the diameter of the piston, D is the inner diameter of the cylinder, and R ｉ is the radius of the i-th set of holes, l is the width of the piston, d is the diameter of the piston rod, and d ｉ is the diameter of the i-th set of holes, s means that the piston has s sets of holes with different diameters, and n ｉ 3. The method of claim 2, wherein x is the number of the i-th set of round holes, x is the displacement of the piston, v is the moving speed of the piston, S is the distance from the surface of the secondary piston to the cross section of the inner wall of the secondary cylinder in the equilibrium stage, h is the height of the gap, and Q is the flow rate.

4. The pore flow and interstitial flow rates of the secondary piston in the second stage are as follows: where m is the flow index, k is the consistency coefficient, and D ０ is the diameter of the piston, D is the inner diameter of the cylinder, and R ｉ is the radius of the i-th set of holes, l is the width of the piston, s means that the piston has s sets of holes with different diameters, and n ｉ is the number of holes in the i-th set, v is the speed of the piston, h is the height of the gap, Δp is the pressure difference across the secondary piston, and Q is the flow rate. Calculate the pressure difference across the second stage secondary piston as: where m is the flow index, k is the consistency coefficient, and D ０ is the diameter of the piston, D is the inner diameter of the cylinder, and R ｉ is the radius of the i-th set of holes, l is the width of the piston, s means that the piston has s sets of holes with different diameters, and n ｉ is the number of holes in the i-th set, v is the speed of the piston, h is the height of the gap, Δp is the pressure difference across the secondary piston, and Q is the flow rate. Calculate the damping force of the second stage secondary piston as: The second stage damping force is equal to the overlap of the primary and secondary pistons: where m is the flow index, k is the consistency coefficient, and D ０ is the diameter of the piston, D is the inner diameter of the cylinder, and R ｉ is the radius of the i-th set of holes, l is the width of the piston, d is the diameter of the piston rod, and d ｉ is the diameter of the i-th set of holes, s means that the piston has s sets of holes with different diameters, and n ｉ 3. The method of claim 2, wherein x is the number of the i-th set of round holes, v is the piston displacement, S is the distance from the surface of the secondary piston to the cross section of the inner wall of the secondary cylinder in the equilibrium stage, h is the height of the gap, and Q is the flow rate.

5. The prediction method includes: calculating a damping coefficient of each stage based on the damping force of the viscous damper of the first stage, the transition stage, or the second stage; The prediction method according to any one of claims 2 to 4, further comprising a step of designing component parameters for a two-stage viscous damper in accordance with the damping coefficient and seismic reduction design target of each stage.

6. The damping coefficients of each stage are as follows:

6. The method of claim 5 .

7. The step of designing component parameters for the two-stage viscous damper according to the damping coefficient and the seismic reduction target of each stage includes: Determining a target damping coefficient and a target damping index according to the seismic isolation design target, the target damping coefficient including a first-order damping coefficient and a second-order damping coefficient; The prediction method according to claim 5, further comprising: designing member parameters for a two-stage viscous damper based on the target damping coefficient and the target damping exponent.

8. The features affecting the primary damping coefficient include the diameter and number of piston holes of the primary piston, the diameter of the primary piston, the width of the primary piston, the diameter of the piston rod, the inner diameter of the main cylinder, the flow index and the consistency coefficient of the damping liquid; The prediction method according to claim 7, characterized in that the features affecting the secondary damping coefficient include, in addition to the features of the primary piston, the diameter and number of piston holes of the secondary piston, the diameter of the secondary piston, the width of the secondary piston, the diameter of the piston rod, the inner diameter of the secondary cylinder, the distance between the inner wall of the secondary cylinder and the secondary piston, the flow index and the consistency coefficient of the damping liquid.

9. Further comprising a transition damping factor; 9. The method of claim 8, wherein the features affecting the transition damping coefficient include, in addition to the features of the primary piston, the diameter and number of piston holes of the secondary piston, the diameter of the secondary piston, the width of the secondary piston, the diameter of the piston rod, the inner diameter of the secondary cylinder, the distance between the inner wall of the secondary cylinder and the secondary piston, the flow index and consistency coefficient of the damping liquid, and the relative displacement relationship between the secondary piston and the variable cross section of the secondary cylinder.

10. A prediction system for damping force of a two-stage viscous damper, wherein when a damper secondary piston of the two-stage viscous damper is in a first stage, the damping force includes a pore flow damping force of a primary piston; when the damper secondary piston is in a transition stage, the damping force includes a pore flow damping force of a primary piston, a gap flow and a pore flow damping force of a secondary piston, the gap flow damping force of the secondary piston being related to a position and a moving speed of the secondary piston; after the damper secondary piston has completely entered a second stage, the damping force includes a pore flow damping force of a primary piston, a gap flow and a pore flow damping force of a secondary piston, the gap flow damping force of the secondary piston being related only to a moving speed of the secondary piston, and the prediction system comprises: A first damping force calculation module for obtaining a pore flow rate of the primary piston in the first stage, and calculating a pressure difference between both ends of the primary piston in the first stage based on the pore flow rate of the primary piston, and calculating a pore damping force of the primary piston as a damping force of a viscous damper in the first stage based on the pressure difference between both ends of the primary piston in the first stage; or A prediction system characterized in that it includes a second damping force calculation module for acquiring a pore flow rate of a primary piston and simultaneously acquiring a sum of a pore flow rate and a gap flow rate of a secondary piston in the transition stage and the second stage, calculating a pressure difference between both ends of the primary piston based on the pore flow rate of the primary piston, calculating a pressure difference between both ends of the secondary piston based on the sum of the pore flow and gap flow rate of the secondary piston, calculating a damping force of the primary piston based on the pressure difference between both ends of the primary piston, calculating a damping force of the secondary piston based on the pressure difference between both ends of the secondary piston, and setting the sum of the pore damping force of the primary piston and the damping force of the secondary piston as the damping force of a viscous damper in the transition stage or the second stage.

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