Vibration reduction transformation and reinforcement method for support between columns of existing plant

Abstract

The invention discloses an existing plant inter-column support vibration reduction transformation and reinforcement method which comprises the following steps: 1, carrying out structure detection on a plant, and evaluating the position and stress condition of an inter-column support; 2, according to a detection result, determining a supporting position where a damper needs to be additionally arranged, and additionally arranging the damper between the inter-column supporting components; thirdly, a damper is installed, and the two ends of the damper are connected with the inter-column supporting original components respectively; and 4, debugging and testing the installed damping system, and verifying and calculating a required damping coefficient so as to meet the requirement of a vibration reduction effect. The damper is additionally arranged, vibration energy is effectively absorbed and dissipated, the influence of mechanical vibration on the plant body is reduced, the installation process is relatively simple, an original structure does not need to be changed on a large scale, the construction period is short, the construction difficulty and time are reduced, and the method is suitable for existing plants of various types; the type and parameters of the damper can be flexibly selected according to the structural characteristics and vibration requirements of different workshops, and transformation is carried out.

Description

Technical Field

[0001] The invention belongs to the technical field of building reinforcement, and in particular is a vibration reduction and reconstruction reinforcement method for inter-column supports of an existing factory building. Background Art

[0002] With the economic transformation and the change of production function requirements, many existing factories need to be reinforced and renovated to adapt to new production processes and / or realize new building functions. Traditional vibration reduction and reinforcement methods often have many shortcomings, such as complex construction, high cost, and large changes to the original structure. At present, there are two main methods for vibration reduction and reinforcement of existing factories: increasing support stiffness and setting vibration reduction and isolation measures for the vibration source. The former is usually achieved by increasing the cross-sectional size or replacing high-strength materials, while the latter uses vibration reduction and isolation materials to physically block the vibration source, absorb and dissipate vibration energy. However, both methods have certain limitations. The method of increasing support stiffness often requires large-scale construction and reconstruction, which is not only costly, but also requires large changes to the original structure, which may affect the normal use of the factory. Although setting vibration reduction and isolation measures for the vibration source can alleviate the vibration problem at the source, due to the complex installation process and high investment cost, it cannot achieve the vibration reduction effect for multiple vibration sources and vibration caused by wind vibration or other factors. Summary of the invention

[0003] The present invention aims to provide a method for vibration reduction and reinforcement structure of inter-column supports of an existing factory building, which can effectively reduce the impact of various vibrations on the main body of the factory building and improve the safety and stability of the factory building. At the same time, it has the advantages of simple construction, low cost, small changes to the original structure, and easy replacement.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] A vibration reduction and reinforcement method for column support of an existing plant building, comprising the following steps:

[0006] Step 1: Conduct structural inspection on the factory building to evaluate the position and stress of the inter-column supports;

[0007] Step 2: According to the test results, determine the displacement amplitude of the steady-state response after vibration reduction and the relevant parameters of the damper, determine the support position where the damper needs to be added, and add the damper between the inter-column support members;

[0008] Step 3: Install the damper, and connect both ends of the damper to the original components of the column support respectively;

[0009] Step 4: Debug and test the installed damping system to verify the calculated damping coefficient to achieve the vibration reduction effect required.

[0010] Preferably, in step 1, the forced vibration analysis for the single degree of freedom system is as follows:

[0011] For a single degree of freedom system with a damper subjected to forced vibration, the equation of motion is:

[0012]

[0013] Where m is the mass, is the acceleration, is the velocity, c is the damping coefficient of the original structure, k is the stiffness, x is the displacement, and F(t) is the external force;

[0014] After installing the damper, the equivalent damping coefficient c of the single degree of freedom system eq becomes:

[0015] c eq =c+c d ;

[0016] where c d is the damping coefficient of the damper.

[0017] Preferably, in step 2, for the two cross-support rods with dampers, when subjected to lateral force, the cross-support generates a lateral displacement Δ, and the required damping coefficient is obtained according to the control requirement of the displacement amplitude:

[0018]

[0019] Where X is the steady-state response displacement amplitude, F0 is the excitation force amplitude, k is the total lateral stiffness of the structure, λ is the frequency ratio, ω is the excitation frequency, ω n is the natural frequency, m is the mass of the structural segment, ξ eq is the damping ratio when there is a damper, c is the damping coefficient of the original structure, c d is the damping coefficient of the damper.

[0020] Preferably, the total lateral stiffness k of the structure is the equivalent lateral stiffness k of the corresponding multiple original column supports. s The stiffness k of the inter-column support with multiple dampers cs The sum of .

[0021] Preferably, the equivalent lateral stiffness k of the original inter-column support is s is the ratio of the lateral force F to the lateral displacement Δ, that is:

[0022]

[0023] The lateral forces for the two original support members are:

[0024]

[0025] Where k1 and k2 are the stiffness of the two original support rods, and θ is the angle between the support rod and the horizontal plane;

[0026] According to the synthesis of forces, the synthetic lateral force of the original support member is

[0027] After adding the damper to the original support rod, according to the mechanical model of the damper, the damping force F c The relationship with speed is:

[0028]

[0029] In the formula, c d is the damping coefficient of the damper, θ is the angle between the support rod and the horizontal plane, where:

[0030]

[0031] In the formula, D is the column spacing, H is the support height, and L is the support rod length;

[0032] The damper has elastic characteristics, and its elastic force F d The relationship with displacement is:

[0033]

[0034] In the formula, k d is the stiffness of the damper part; the total force of the damper is:

[0035] When in steady state, the displacement derivative is 0, which is equivalent to the support rod being divided into only two parts, the stiffness coefficient of the retained part is 2k1, and the stiffness of the damper part is k d , then the stiffness coefficients of the two rods with dampers added are:

[0036]

[0037]

[0038] Then the stiffness coefficients of the two rods with dampers are:

[0039] According to the force synthesis and equivalence principle, the synthetic lateral force of the two supporting rods with the damper added is:

[0040]

[0041] Preferably, after adding the damper, the equivalent lateral stiffness of the entire support is the ratio of the synthetic lateral force F′ to the lateral displacement Δ, that is,

[0042]

[0043] where k cs is the inter-column support stiffness after adding the damper.

[0044] Preferably, in step 4, the required damping coefficient is obtained according to the control requirements of the displacement amplitude:

[0045]

[0046] ξ eq =(c+c d ) / 2mω;

[0047] Where X is the steady-state response displacement amplitude. For simple harmonic excitation F(t)=F0sin(ωt), the steady-state response of the system is F0 is the excitation force amplitude, k is the total lateral stiffness of the structure, is the phase difference, t is the time, is the frequency ratio, ω is the excitation frequency, is the natural frequency, m is the mass of the structural segment, c is the damping coefficient of the original structure, c d The damping coefficient provided by the damper, ξ eq is the damping ratio when there is a damper.

[0048] Preferably, for a plant divided into different structural sections, vibration reduction and reinforcement can be carried out in different sections according to different requirements, that is, the inter-column support stiffness k of different structural sections cs Different parameters will result in different vibration reduction effects.

[0049] Preferably, if the factory roof vibrates, the roof support can be damped in the same manner.

[0050] Compared with the prior art, the present invention has the following beneficial effects:

[0051] 1. Significant vibration reduction: By adding dampers, the vibration energy can be effectively absorbed and dissipated, reducing the impact of mechanical vibration on the main body of the plant.

[0052] 2. Easy construction: The installation process is relatively simple, and no large-scale changes to the original structure are required. The construction period is short, which reduces the difficulty and time of construction.

[0053] 3. Low cost: Compared with traditional reinforcement methods, the present invention has lower cost and higher economic benefits.

[0054] 4. Strong adaptability: The present invention is applicable to various types of existing factory buildings. The type and parameters of the damper can be flexibly selected according to the structural characteristics and vibration requirements of different factory buildings for customized transformation. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] In order to make the objectives, technical solutions and advantages of the present disclosure more clearly understood, the technical solutions of the present disclosure are further described in detail below in combination with specific embodiments and with reference to the following drawings.

[0056] Figure 1 It is a schematic diagram of the cross support type between columns and the additional damper;

[0057] Figure 2 This is a schematic diagram of the column support type and the additional damper;

[0058] Figure 3 Schematic diagram of a vibration damper and a connecting end of an embodiment;

[0059] Figure 4 Schematic diagram of adding vibration dampers to the cross-bracing members between columns;

[0060] Figure 5 Schematic diagram of adding vibration dampers to the inter-column support members;

[0061] Figure 6 Schematic diagram of the calculation of lateral stiffness of column supports. DETAILED DESCRIPTION

[0062] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0063] In this embodiment, the vibration reduction and reinforcement of the column supports of the existing factory building is firstly evaluated to determine the positions of the column supports that need to be modified and added with dampers, such as Figure 1 a, b and Figure 2 As shown in a and b, at one end of the diagonal rod or horizontal rod supporting the column, a corresponding damper is added by cutting and replacing the component (indicated by the corrugated line in the figure).

[0064] like Figure 3 As shown, at the selected inter-column support position, a damper 2 is added between the inter-column support components, and both ends of the damper are connected to the inter-column support original component 1 in a simple and reliable manner (such as Figure 4 , Figure 5 The type and parameters of the damper should be selected according to the specific conditions and vibration characteristics of the plant, such as viscous dampers, metal dampers, etc. The installation of the damper should ensure firmness and reliability, and the connection with the original column support components and the plant structure should meet the design requirements.

[0065] A vibration reduction and reinforcement method for the inter-column support of an existing factory building in this embodiment includes the following steps:

[0066] Step 1: Conduct structural inspection on the factory building, and determine the actual stress of the inter-column supports based on the spatial position of the inter-column supports according to the nature and size of the factory building's use load and vibration load;

[0067] Step 2: According to the test results and theoretical calculations, the displacement amplitude of the steady-state response after vibration reduction is determined, the relevant parameters of the designed damper are determined, the support position of the additional damper is determined, and the damper is added between the inter-column support members;

[0068] Step 3: Install the damper. Connect both ends of the damper to the original components of the column support to ensure that the connection is firm and reliable.

[0069] Step 4: Debug and test the installed damping system to ensure that the required damping coefficient is achieved and that its vibration reduction effect meets the design requirements.

[0070] For the structural shaking caused by vibration in a single-story factory building, dampers are used to reduce vibration. The following relevant formula can be used for analysis:

[0071] Analysis of forced vibration of single-degree-of-freedom system and damper action, equation of motion of single-degree-of-freedom system: For forced vibration of single-degree-of-freedom system with damper, its equation of motion is:

[0072]

[0073] Where m is the mass, is the acceleration, is the velocity, c is the damping coefficient of the original structure, k is the stiffness, x is the displacement, and F(t) is the external force.

[0074] When the damper is installed, the equivalent damping coefficient c of the single degree of freedom system is eq becomes:

[0075] c eq =c+c d ;

[0076] where c d is the damping coefficient of the damper.

[0077] Calculating the lateral stiffness of the cross support with a damper: This embodiment derives a calculation formula for the lateral stiffness of the cross support with a damper, taking the cross support as an example. The calculation process for other types of supports is similar.

[0078] Assume that the stiffness of the two supports of the cross support are k1 and k2 respectively, the column spacing is D, the support height is H, and the angle between the support rod and the horizontal plane is θ, then the length of the support rod is After one of the supporting rods is replaced with a damper, the damping coefficient of the damper is cd , the equivalent stiffness is k d ,in When subjected to lateral force, the cross support will produce a lateral displacement Δ.

[0079] Considering that the linear stiffness of the steel columns on both sides and the transverse crane beam is much greater than the linear stiffness of the supporting rods, the model is simplified as follows Figure 6 shown.

[0080] The lateral forces of the two original support members of the cross brace are:

[0081] According to the synthesis of forces, the synthetic lateral force of the original support member with cross bracing is

[0082] Equivalent lateral stiffness k of the original column support s is the ratio of the lateral force F to the lateral displacement Δ, that is:

[0083]

[0084] After adding a damper to the support rod, according to the mechanical model of the damper, the damping force F c The relationship with speed is:

[0085] Represents the first derivative of displacement.

[0086] At the same time, the damper also has elastic characteristics, and the relationship between its elastic force and displacement is:

[0087] Therefore, the total force on the damper is:

[0088] When in steady state, the displacement derivative is 0, which is equivalent to the support rod being divided into only two parts, the stiffness coefficient of the retained part is 2k1, and the stiffness of the damper part is k d , then the stiffness coefficients of the two rods with dampers added are:

[0089]

[0090] Then the lateral forces of the two supporting rods with dampers are:

[0091] According to the force synthesis and equivalence principle, the synthetic lateral force of the two supporting rods with the damper added is:

[0092]

[0093] After adding the damper, the equivalent lateral stiffness of the entire support structure is the ratio of the synthetic lateral force F′ to the lateral displacement Δ, that is:

[0094]

[0095] where k cs is the inter-column support stiffness after adding the damper.

[0096] The equivalent lateral stiffness k of multiple original column supports can be calculated s and the stiffness k of the inter-column support with multiple dampers cs It is superimposed as the total lateral stiffness k of the structure and participates in the following damped vibration response calculation.

[0097] The damped vibration response is calculated in the following way: Determine the structural parameters, taking a expansion joint group of the factory building as a structural segment. Determine the mass m of a structural segment, the total lateral stiffness k of the structure, and the damping coefficient c of the original structure. Determine the damping coefficient c provided by the damper through the type and specification of the damper. d , calculate the natural frequency and damping ratio ξ=c / 2mω n , the damping ratio ξ with a damper eq =(c+c d ) / 2mω, ω is the excitation frequency.

[0098] According to the principle of structural dynamics, for simple harmonic excitation F(t) = F0sin(ωt), the steady-state response of the system is Its steady-state response displacement amplitude is According to the control requirements of displacement amplitude, reverse calculation is performed to obtain the required damping coefficient, where F0 is the excitation force amplitude, ω is the excitation frequency, is the phase difference, t is the time, is the frequency ratio.

[0099] It is obvious to those skilled in the art that the present application is not limited to the details of the exemplary embodiments described above, and that the present application can be implemented in other specific forms without departing from the spirit or essential features of the present application. Therefore, the embodiments should be regarded as exemplary and non-limiting in all respects, and the scope of the present application is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present application. Any reference numeral in a claim should not be regarded as limiting the claim to which it relates.

Claims

1. A vibration reduction and reinforcement method for the inter-column support of an existing plant, characterized in that: The following steps are involved: Step 1: Conduct structural inspection on the factory building to evaluate the position and stress of the inter-column supports; Step 2: According to the test results, determine the displacement amplitude of the steady-state response after vibration reduction and the relevant parameters of the damper, determine the support position where the damper needs to be added, and add the damper between the inter-column support members; Step 3: Install the damper, and connect both ends of the damper to the original components of the column support respectively; Step 4: Debug and test the installed damping system to verify the calculated damping coefficient to achieve the vibration reduction effect required.

2. The vibration reduction and reinforcement method for the inter-column support of an existing factory building according to claim 1 is characterized in that: In step 1, the forced vibration analysis of the single degree of freedom system is as follows: For a single degree of freedom system with a damper subjected to forced vibration, the equation of motion is: Where m is the mass, is the acceleration, is the velocity, c is the damping coefficient of the original structure, k is the stiffness, x is the displacement, and F(t) is the external force; After installing the damper, the equivalent damping coefficient c of the single degree of freedom system eq becomes: c eq =c+c d ; where c d is the damping coefficient of the damper.

3. The vibration reduction and reinforcement method for inter-column supports of an existing factory building according to claim 1 is characterized in that: In step 2, for the two cross-bracing rods with dampers, when subjected to lateral force, the cross-bracing generates a lateral displacement Δ, and the required damping coefficient is obtained according to the control requirements of the displacement amplitude: x eq =(c+c d ) / 2mω; Where X is the steady-state response displacement amplitude, F0 is the excitation force amplitude, k is the total lateral stiffness of the structure, λ is the frequency ratio, ω is the excitation frequency, ω n is the natural frequency, m is the mass of the structural segment, ξ eq is the damping ratio when there is a damper, c is the damping coefficient of the original structure, c d is the damping coefficient of the damper.

4. The vibration reduction and reinforcement method for column support of an existing factory building according to claim 3 is characterized in that: The total lateral stiffness k of the structure is the equivalent lateral stiffness k of the corresponding multiple original column supports. s The stiffness k of the inter-column support with multiple dampers cs The sum of .

5. The vibration reduction and reinforcement method for the inter-column support of an existing factory building according to claim 4 is characterized in that: The equivalent lateral stiffness k of the original column support s is the ratio of the lateral force F to the lateral displacement Δ, that is: The lateral forces for the two original support members are: Where k1 and k2 are the stiffness of the two original support rods, and θ is the angle between the support rod and the horizontal plane; According to the synthesis of forces, the synthetic lateral force of the original support member is After adding the damper to the original support rod, according to the mechanical model of the damper, the damping force F c The relationship with speed is: In the formula, c d is the damping coefficient of the damper, θ is the angle between the support rod and the horizontal plane, where: In the formula, D is the column spacing, H is the support height, and L is the support rod length; The damper has elastic characteristics, and its elastic force F d The relationship with displacement is: In the formula, k d is the stiffness of the damper part; the total force of the damper is: When in steady state, the displacement derivative is 0, which is equivalent to the support rod being divided into only two parts, the stiffness coefficient of the retained part is 2k1, and the stiffness of the damper part is k d , then the stiffness coefficients of the two rods with dampers added are: Then the stiffness coefficients of the two rods with dampers are: According to the force synthesis and equivalence principle, the synthetic lateral force of the two supporting rods with the damper added is:

6. The vibration reduction and reinforcement method for inter-column supports of an existing factory building according to claim 5 is characterized in that: After adding the damper, the equivalent lateral stiffness of the entire support is the ratio of the composite lateral force F′ to the lateral displacement Δ, that is, where k cs is the inter-column support stiffness after adding the damper.

7. The vibration reduction and reinforcement method for the inter-column support of an existing factory building according to claim 1 is characterized in that: In step 4, the required damping coefficient is obtained according to the control requirements of the displacement amplitude: Where X is the steady-state response displacement amplitude. For simple harmonic excitation F(t)=F0sin(ωt), the steady-state response of the system is F0 is the excitation force amplitude, k is the total lateral stiffness of the structure, is the phase difference, t is the time, is the frequency ratio, ω is the excitation frequency, is the natural frequency, m is the mass of the structural segment, c is the damping coefficient of the original structure, c d The damping coefficient provided by the damper, ξ eq is the damping ratio when there is a damper.

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