CN115828359A - Safety assessment method, system, equipment and medium for wind power test bed foundation - Google Patents
Safety assessment method, system, equipment and medium for wind power test bed foundation Download PDFInfo
- Publication number
- CN115828359A CN115828359A CN202211194955.6A CN202211194955A CN115828359A CN 115828359 A CN115828359 A CN 115828359A CN 202211194955 A CN202211194955 A CN 202211194955A CN 115828359 A CN115828359 A CN 115828359A
- Authority
- CN
- China
- Prior art keywords
- pile
- maximum
- load
- test bed
- parameters
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Landscapes
- Testing Of Devices, Machine Parts, Or Other Structures Thereof (AREA)
Abstract
The invention provides a safety evaluation method, a system, equipment and a medium for a wind turbine generator test bed foundation, wherein the evaluation method comprises the steps of obtaining intrinsic parameters of the test bed foundation and extreme working condition parameters, operation working condition parameters and earthquake working condition parameters in a whole life cycle, simulating the stress condition of the test bed foundation during working by using a pre-constructed finite element model to obtain the limit load and the fatigue load of the test bed foundation, and checking the limit strength and the fatigue strength of the test bed foundation based on the intrinsic parameters, the extreme working condition parameters, the operation working condition parameters, the earthquake working condition parameters, the limit load and the fatigue load, so that the design safety of the test bed foundation is accurately evaluated.
Description
Technical Field
The invention relates to the technical field of wind power generation, in particular to a safety assessment method, a system, equipment and a medium for a wind power test bed foundation.
Background
With the maturity of wind power technology, the wind power industry has entered a fast growth period. Accordingly, wind turbine generator capacity and size are increasing. Before the wind turbine generator system is put into the market, in order to verify the working performance of core components, a fan manufacturer often needs to carry out 1:1 physical condition test. As the most basic structure for the operation of the test stand, the test stand foundation should provide sufficient rigid support, bear all loads (including gravity, reaction forces), and the like. In order to effectively evaluate the safety performance of the test bed or evaluate the maximum testing capability of the built test bed, a set of standardized test bed safety evaluation flow is urgently needed.
At present, a large-scale test bed of a wind turbine generator is mostly a blade test bed. The design of a transmission chain and a blade test bed and the lack of corresponding standards guide the design and check work, and the safety factor value is usually conservative. Along with the gradual increase of the capacity of the wind turbine generator, higher requirements are provided for the testing capacity of the test bed, the foundation of the test bed is required to bear larger load, the capacity of the fan is increased in a nonlinear mode, and the difficulty in building and construction is greatly increased due to the fact that the test bed is designed in a mode of improving the safety coefficient. At present, basic design check work mainly refers to corresponding standards of the building industry, and a unified calculation check flow does not exist. In addition, the wind turbine generator test bed such as a transmission chain test bed and a blade test bed needs to experience dynamic load, and the influence of the dynamic load needs to be considered when the test bed foundation is designed and checked. And thus lack a uniform security assessment methodology.
Disclosure of Invention
In order to solve the problems that the design safety check of the existing wind turbine generator test bed foundation lacks a unified safety evaluation method and flow and the calculation check result is inaccurate, the invention provides a safety evaluation method of the wind turbine generator test bed foundation, which comprises the following steps:
acquiring inherent parameters of the test bed foundation and extreme working condition parameters, operation working condition parameters and earthquake working condition parameters in the whole life cycle;
respectively substituting the extreme working condition parameters, the operating working condition parameters and the earthquake working condition parameters into a pre-constructed finite element model, and performing stress simulation on the test bed foundation by using the finite element model to obtain the limit load and the fatigue load of the test bed foundation;
performing limit strength check and fatigue strength check on the test bed foundation based on the inherent parameters, the extreme working condition parameters, the operating working condition parameters, the earthquake working condition parameters, the limit load and the fatigue load;
wherein the intrinsic parameters comprise soil mechanical parameters, structural parameters and mechanical property parameters of the test bed foundation.
Preferably, the limit load comprises a maximum axial tensile load and a maximum axial compressive load of the pile leg, and the fatigue load comprises a maximum compressive stress and a minimum compressive stress of the concrete and a maximum tensile stress and a minimum tensile stress of the steel bar.
Preferably, the performing the ultimate strength check and the fatigue strength check on the test bed foundation based on the extreme working condition parameter, the operating working condition parameter, the earthquake working condition parameter, the ultimate load and the fatigue load comprises:
checking the bearing capacity of the pile leg based on the maximum axial tensile load and the maximum axial compressive load of the pile leg;
and checking the fatigue strength of the reinforced concrete part of the test bed foundation based on the maximum compressive stress and the minimum compressive stress of the concrete and the maximum tensile stress and the minimum tensile stress of the reinforcing steel bar, wherein the reinforced concrete part comprises a pile foundation pile cap, a supporting structure on the upper part of the pile foundation pile cap and an anchoring device inside the pile foundation pile cap.
Preferably, the load capacity calibration of the leg based on the maximum axial tensile load and the maximum axial compressive load of the leg comprises:
calculating to obtain the maximum tensile bearing capacity and the maximum compressive bearing capacity of the pile leg based on the soil mechanics parameters by respectively combining a maximum tensile bearing capacity calculation formula and a maximum compressive bearing capacity calculation formula;
and respectively comparing the maximum axial tensile load and the maximum axial compressive load with the maximum tensile bearing capacity and the maximum compressive bearing capacity, wherein if the maximum axial tensile load and the maximum axial compressive load are respectively smaller than the maximum tensile bearing capacity and the maximum compressive bearing capacity, the bearing capacity of the pile leg is qualified, otherwise, the bearing capacity of the pile leg is unqualified.
Preferably, the maximum tensile load capacity is calculated as follows:
in the formula, F a Maximum tensile bearing capacity, R, of a single pile s As side friction resistance, R b Is pile end resistance, m is tensile bearing capacity reduction coefficient, fs i Is the ultimate frictional resistance characteristic value f of the rock soil around the ith soil layer pile p For the ith soil layer pile end rock soilCharacteristic value of extreme end resistance, thk i The thickness of the soil layer of the ith geological section is shown, D is the diameter of the pile leg, and n is the total number of the soil layers of the geological section.
Preferably, the maximum compressive load capacity is calculated as follows:
in the formula, F a ' maximum compressive load bearing capacity of a monopile, R s As side friction resistance, R b Is pile end resistance, c is compression bearing reduction factor, fs i Is the ultimate frictional resistance characteristic value f of the rock soil around the ith soil layer pile p Is the ultimate end resistance characteristic value, thk, of the ith soil layer pile end rock soil i The thickness of the soil layer of the ith geological section is shown, D is the diameter of the pile leg, and n is the total number of the soil layers of the geological section.
Preferably, the checking the fatigue strength of the steel-concrete part of the test bed foundation based on the maximum compressive stress and the minimum compressive stress of the concrete and the maximum tensile stress and the minimum tensile stress of the steel bar comprises:
calculating to obtain the maximum load times of the concrete under the alternating stress based on the maximum compressive stress and the minimum compressive stress of the concrete and the maximum load time calculation formula of the concrete, and calculating to obtain the maximum load times of the reinforcing steel bar under the alternating stress based on the maximum tensile stress and the minimum tensile stress of the reinforcing steel bar and the S-N curve formula of the reinforcing steel bar;
if the ratio of the actual loading times of the concrete to the maximum loading times which can be borne by the concrete and the ratio of the actual loading times of the reinforcing steel bars to the maximum loading times which can be borne by the reinforcing steel bars are both smaller than 1, the fatigue strength of the reinforced concrete structure is qualified, otherwise, the fatigue strength of the reinforced concrete structure is unqualified.
Preferably, the calculation formula of the maximum load times of the concrete is shown as the following formula:
in the formula, N 1 The maximum number of times of load that the concrete can bear under alternating stress, E cd，max Is the maximum compressive stress level, R, of the concrete i The stress ratio of the concrete is shown.
Preferably, the curve formula is shown as follows:
wherein, delta sigma is amplitude of alternating stress, N is maximum load times of the steel bar under the alternating stress, and N is * Is 10 6 ，k 1 、k 2 logN on S-N curves of reinforcing bars respectively * Corresponding to the slope of the curve on both sides of the position.
Preferably, the security assessment method further comprises:
carrying out modal calculation on the test bed foundation by using the finite element model to obtain the modal frequency of the test bed foundation;
and comparing the modal frequency with the rotating frequency range of the wind turbine generator to be tested, if the modal frequency falls within the rotating frequency range, determining that the rigidity of the test bed foundation is unqualified, otherwise, determining that the rigidity of the test bed foundation is qualified.
Preferably, the security evaluation method further includes:
establishing a finite element model of the pile foundation pile cap and the supporting structure by adopting a shell unit, and establishing a finite element model of the pile leg by adopting a beam unit;
setting boundary conditions for the finite element model of the pile leg, wherein the boundary conditions comprise a horizontal stiffness coefficient, a vertical stiffness coefficient and a rotational stiffness coefficient;
and constructing the finite element model of the test bed foundation by the finite element models of the pile foundation cap and the supporting structure, the finite element model of the pile leg and the boundary conditions.
Preferably, the setting of boundary conditions for the finite element model of the leg comprises:
and respectively combining a horizontal rigidity coefficient formula, a pile end vertical rigidity coefficient formula and a rotary rigidity coefficient formula to set the horizontal rigidity coefficient, the vertical rigidity coefficient and the rotary rigidity coefficient based on the structural parameters and the mechanical property parameters of the pile leg.
Preferably, the horizontal stiffness coefficient is represented by the following formula:
wherein, K h The horizontal stiffness coefficient is arranged along the length of the pile, L is the buried depth length of the pile leg, T is the elastic length, EI is the bending stiffness, E is the elastic modulus, and I is the section moment of inertia.
Preferably, the pile tip vertical stiffness coefficient is expressed by the following formula:
wherein, K v Is the pile tip vertical stiffness coefficient, N p For the vertical compressive load borne by the pile, s is the vertical compressive load subsidence value borne by the pile, Q h For settling loads, L c To calculate the length, D is the diameter of the leg, A is the net area of the section of the pile, and E is the modulus of elasticity.
Preferably, the rotational stiffness coefficient is represented by the following formula:
wherein, K θ The coefficient of rotational stiffness is L, the length of the embedded depth of the pile leg is T, the elastic length is T, EI is bending stiffness, E is elastic modulus, and I is the section moment of inertia.
Preferably, the shell element is a 4-node.
Based on the same idea, the invention also provides a safety evaluation system based on the wind turbine generator test bed, which comprises:
the acquisition module is used for acquiring inherent parameters of the test bed foundation and extreme working condition parameters, operation working condition parameters and earthquake working condition parameters in the whole life cycle;
the simulation module is used for substituting the extreme working condition parameters, the operating working condition parameters and the earthquake working condition parameters into a pre-constructed finite element model respectively, and performing stress simulation on the test bed foundation by using the finite element model to obtain the limit load and the fatigue load of the test bed foundation;
the checking module is used for checking the ultimate strength and the fatigue strength of the test bed foundation based on the inherent parameters, the extreme working condition parameters, the operating working condition parameters, the earthquake working condition parameters, the ultimate load and the fatigue load;
wherein the intrinsic parameters comprise soil mechanical parameters, structural parameters and mechanical property parameters of the test bed foundation.
Preferably, the checking module includes:
the ultimate strength checking unit is used for checking the bearing capacity of the pile leg based on the maximum axial tensile load and the maximum axial compressive load of the pile leg;
and the fatigue strength checking unit is used for checking the fatigue strength of the reinforced concrete part of the test bed foundation based on the maximum compressive stress and the minimum compressive stress of the concrete and the maximum tensile stress and the minimum tensile stress of the steel bar, and the reinforced concrete part comprises a pile foundation bearing platform, an anchoring device and a supporting structure on the upper part of the pile foundation bearing platform. .
Based on the same invention idea, the invention further provides a computer device, comprising: one or more processors; the processor to store one or more programs; when the one or more programs are executed by the one or more processors, the safety evaluation method of the wind turbine generator test bed foundation provided by the invention is realized.
Based on the same invention idea, the invention further provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed, the safety evaluation method of the wind turbine generator test bed foundation provided by the invention is realized.
Compared with the prior art, the invention has the beneficial effects that:
according to the safety evaluation method and system for the wind turbine generator test bed foundation, the inherent parameters of the test bed foundation and the extreme working condition parameters, the operating condition parameters and the earthquake working condition parameters in the whole life cycle are obtained, the stress condition of the test bed foundation during working is simulated by using the pre-constructed finite element model, the limit load and the fatigue load of the test bed foundation are obtained, and the limit strength check and the fatigue strength check are carried out on the test bed foundation based on the inherent parameters, the extreme working condition parameters, the operating condition parameters, the earthquake working condition parameters, the limit load and the fatigue load, so that the design safety of the test bed foundation is accurately evaluated.
Drawings
FIG. 1 is a schematic flow chart of a safety assessment method for a wind turbine generator test bed foundation provided by the invention;
fig. 2 is a schematic sectional structure view of a large-scale wind turbine generator test bed foundation provided in embodiment 1 of the present invention;
FIG. 3 is a schematic diagram of a safety evaluation process of a test bench base provided in embodiment 1 of the present invention;
FIG. 4 is a schematic diagram of S-N curves of a steel bar of a test bed foundation provided in embodiment 1 of the present invention;
FIG. 5 is a schematic diagram of four security check positions of a bench-based anchoring device provided in example 1 of the present invention;
reference numerals: 1. pile legs; 2. a pile foundation bearing platform; 3. a support structure; 4. an anchoring device.
Detailed Description
For a better understanding of the present invention, reference is made to the following description taken in conjunction with the accompanying drawings.
Example 1:
a large-scale wind turbine generator test bed foundation is mainly composed of pile legs 1, a pile foundation bearing platform 2, a supporting structure 3 and an anchoring device 4, as shown in figure 2. The external load is finally transmitted to the pile leg 1 through the anchoring device 4 and the pile foundation cap 2.
The embodiment provides a safety assessment method for a wind turbine generator test bed foundation, which is used for performing safety assessment on a design structure of the test bed foundation, and as shown in fig. 1, the safety assessment method includes:
step 1: acquiring inherent parameters of a test bed foundation and extreme working condition parameters, operation working condition parameters and earthquake working condition parameters in a whole life cycle;
step 2: respectively substituting the extreme working condition parameters, the operating working condition parameters and the earthquake working condition parameters into a pre-constructed finite element model, and performing stress simulation on the test bed foundation by using the finite element model to obtain the ultimate load and the fatigue load of the test bed foundation;
and step 3: performing limit strength check and fatigue strength check on the test bed foundation based on the inherent parameters, the extreme working condition parameters, the operating working condition parameters, the earthquake working condition parameters, the limit load and the fatigue load;
the intrinsic parameters comprise soil mechanics parameters, structural parameters and mechanical property parameters of the test bed foundation.
The safety assessment method can be used for carrying out safety assessment on the design of a large-scale test bed foundation, more comprehensively and accurately assessing the safety performance of the test bed foundation in the whole life cycle, and meanwhile, the method is also used for assessing the maximum testing capability of the built test bed.
The following is a specific implementation procedure of the security assessment method.
Before step 1, a finite element model of a test bed foundation is first established.
The pile foundation cap 2 and the supporting structure 3 on the upper portion are simulated by adopting 4-node shell units. The legs 1 are beam units. Boundary conditions: arranging springs along the direction of the pile leg 1, and setting a horizontal stiffness coefficient, a vertical stiffness coefficient and a rotational stiffness coefficient (K) h 、K v 、K θ )。
The calculation formula of the horizontal stiffness coefficient arranged along the pile length is as follows:
in the formula, K h The horizontal stiffness coefficient is L, the leg burial depth length is L, the elastic modulus is E, the section inertia moment is I, the bending stiffness is EI, and the elastic length is T.
For sandy geology, the elastic length calculation is:
wherein T is the elastic length, EI is the bending rigidity, n h The geological coefficient is determined according to the loose degree of the soil (the more compact the soil is, the larger the numerical value is), and the value is 1-20.
For clay geology, the elastic length calculation is:
wherein T is the elastic length, EI is the bending stiffness, s u The shear strength is non-drainage shear strength.
The equivalent length calculation formula of the pile leg is as follows:
in the formula, L eq The equivalent length of the pile leg, L the buried depth length of the pile leg and T the elastic length.
The cross-sectional moment of inertia I is calculated as:
wherein D is the diameter of the pile leg
The calculation formula of the pile end vertical rigidity coefficient is as follows:
in the formula, K v Is the pile tip vertical stiffness coefficient, N p For the vertical compressive load borne by the pile, s is the vertical compressive load subsidence value borne by the pile, Q h For settling loads, L c To calculate the length (equal to the equivalent length of the leg minus 1/3 of the leg's buried depth length), D is the diameter of the leg, A is the net area of the pile section, and E is the modulus of elasticity.
Coefficient of rotational stiffness K θ The calculation formula of (A) is as follows:
wherein, K θ The coefficient of rotational stiffness is L, the length of the embedded depth of the pile leg is T, the elastic length is T, the bending stiffness is EI, the elastic modulus is E, and the section moment of inertia is I.
And 2, respectively substituting the extreme working condition parameters, the operating working condition parameters and the earthquake working condition parameters into a pre-constructed finite element model, and performing stress simulation on the test bed foundation by using the finite element model to obtain the limit load and the fatigue load of the test bed foundation, wherein the limit load comprises the maximum axial tensile load and the maximum axial compressive load of the pile leg 1, the fatigue load comprises the maximum compressive stress and the minimum compressive stress of the concrete at the steel-concrete part and the maximum tensile stress and the minimum tensile stress of the steel bar, the steel-concrete part such as the pile foundation 2 and the supporting structure 3, and the position III (concrete conical surface failure) and the position IV (concrete failure under the condition that the surface steel plate is pressed) of the anchoring device 4, as shown in fig. 5. And carrying out limit strength check and fatigue strength check on the test bed foundation based on the inherent parameters of the test bed foundation, such as soil mechanics parameters, structural parameters and mechanical property parameters, and the extreme working condition parameters, the operating working condition parameters, the earthquake working condition parameters, the limit load and the fatigue load of the test bed foundation.
(1) Ultimate strength check
a. Bearing capacity checking of a pile leg 1
Calculating the maximum bearing capacity of the pile leg by adopting a maximum bearing capacity calculation formula;
according to the soil mechanics parameters, the following formula is adopted to calculate the maximum bearing capacity of the single pile:
F max ＝R s +R b
in the formula, F max Is the maximum bearing capacity of a single pile, R s As side friction resistance, R b Is the pile tip resistance.
The calculation formula of the side friction resistance is as follows:
in the formula, fs i The ultimate frictional resistance characteristic value of the rock soil around the ith soil layer pile, D is the diameter of the pile leg, thk i Is the thickness of the soil layer of the ith geological section.
The calculation formula of the pile end resistance is as follows:
in the formula (f) p And the resistance characteristic value of the ultimate end of the rock soil at the ith soil layer pile end is obtained.
Loading single pile in maximum tension F p Maximum compressive load F c And respectively comparing the bearing capacity with the maximum bearing capacity, and judging whether the bearing capacity of the pile leg is proper or not. The bearing capacity is correspondingly reduced in consideration of pile group effect. The reduction coefficient of the compressive bearing capacity is 0.85, and the reduction coefficient of the tensile bearing capacity is 0.7.
The calculation formula of the maximum tensile bearing capacity after the reduction is as follows:
F a ＝(R s +R b )×m，
in the formula, F a Maximum tensile bearing capacity, R, of a single pile s As side friction resistance, R b For the pile end resistance, m is the tensile load reduction coefficient, and 0.7 is selected in this embodiment.
The calculation formula of the maximum compressive bearing capacity after the reduction is as follows:
F a ′＝(R s +R b )×c，
in the formula, F a ' maximum compressive load bearing capacity of a monopile, R s As side friction resistance, R b For pile end resistance, c is the compressive load reduction factor, which is 0.85 in this embodiment.
If the maximum axial tensile load and the maximum axial compressive load of the pile leg 1 are respectively smaller than the maximum tensile bearing capacity and the maximum compressive bearing capacity, the bearing capacity of the pile leg 1 is qualified, otherwise, the bearing capacity of the pile leg 1 is unqualified.
The maximum bending moment of the single pile under the limiting working condition can be calculated according to the recognized standards such as national standard or European standard, and whether the reinforcing steel bars of the section are reasonable or not can be checked.
b. Checking the ultimate strength of pile foundation bearing platform 2 and supporting structure 3
Through finite element analysis, find the biggest, the biggest operating mode of shear force, axial force of the biggest of pile foundation cushion cap 2 and 3 bending moments of bearing structure respectively for develop: checking the bending moment, and checking whether the bending reinforcing bars are reasonable or not; and (5) shearing force checking, and checking whether shearing force reinforcing bars are reasonable or not. The subentry safety coefficient of the concrete can be 1.5, and the subentry safety coefficient of the reinforcing steel bar can be 1.15.
c. Checking the ultimate strength of the anchoring points 4
As shown in fig. 5, according to the actual stress characteristics, the anchoring device 4 has four key safety checking positions: the bolt body at the position I, the steel structure contacted with the bolt body at the position II, the concrete conical surface at the position III and the concrete below the surface steel plate at the position IV.
Carrying out finite element analysis on the test bed foundation by using a finite element model of the test bed foundation, simulating loads of each operation condition, extracting a calculation result to obtain the ultimate stress of four key safety check positions, and checking the ultimate strength according to the following formula:
σ＝F/S≤σ s
wherein σ is the ultimate stress at the safety check position, F is the ultimate load at the safety check position, S is the effective acting area at the safety check position, and σ is s Is the yield limit.
(2) Fatigue strength check
a. Fatigue strength check of reinforced concrete part
The pile foundation bearing platform 2 and the supporting structure 3 are both steel-concrete structures, and the maximum load times which can be borne by concrete and steel bars under alternating stress are checked respectively.
Carrying out finite element analysis by using a finite element model, finding out the working condition corresponding to the maximum stress range of the section in all the operating working conditions, and extracting the maximum compressive stress sigma of the concrete c，max Minimum compressive stress σ c，min Maximum extension stress sigma of steel bar s，max Minimum tensile stress sigma of steel bar s，min . The working condition is regarded as the only operation working condition in the full service period. At this time, the concrete alternating stress range is determined by the following formula:
σ c，range ＝σ c，max -σ c，min
in the formula, σ c，range For the range of alternating stress of the concrete, σ c，max Is the maximum compressive stress of concrete, sigma c，min The minimum compressive stress for the concrete.
1) Concrete and its production method
Concrete in alternating stress range sigma c，range Next, the maximum number of times of bearable load is determined by the following equation:
in the formula, N 1 Number of times of maximum load of concrete, E cd，max At the maximum compressive stress level, R i At a minimum compressive stress level and at a maximumRatio of compressive stress levels.
The maximum compressive stress level is calculated by:
in the formula, E cd，max Is the maximum compressive stress level, σ, of the concrete c，max Is the maximum compressive stress of the concrete, f cd，fat Fatigue strength is designed for concrete.
The minimum compressive stress level is calculated by:
in the formula, E cd，min Is the minimum compressive stress level, σ, of the concrete c，min Is the minimum compressive stress of concrete, f cd，fat Fatigue strength is designed for concrete.
The stress ratio is calculated by the following formula:
in the formula, R i As a stress ratio, E cd，min To a minimum compressive stress level, E cd，max Is the maximum compressive stress level.
The design fatigue strength of the concrete was calculated by the following formula:
in the formula (f) cd，fat Design of fatigue Strength, f, for concrete ck Is a standard value of the compressive strength of the concrete axis, is obtained by geological survey geotechnical test, k is a concrete strength reduction coefficient depending on the age of the concrete, and beta cc Coefficient of dependence on age of concrete, gamma c Is a concrete itemized safetyThe total coefficient (permanent and temporary load value 1.5, unexpected load value 1.2).
The judgment criterion of the concrete safety is as follows: the ratio of the actual number of loads to the maximum number of loads N must be less than 1. The actual loading times can be provided by a fan manufacturer according to the scene of the test of the transmission chain of the wind turbine generator or the whole life cycle of the blade.
2) Reinforcing bar
The S-N curve of a common straight and curved steel bar (except for welding and hinging) is shown in fig. 4, and the curve formula is:
in the formula: delta sigma is the amplitude of the alternating stress of the steel bar, N is the maximum load times that the steel bar can bear in the stress range, k1 and k2 are logN on the S-N curve of the steel bar respectively * The slope of the curve on both sides of the corresponding position, k1=5; k2=9,n * ＝10 6 ，Δσ Rsk Is N * Corresponding amplitude of alternating stress, N * Corresponding delta sigma Rsk ＝162.5Mpa。
The amplitude Δ σ of the alternating stress of the rebar is determined by:
Δσ＝σ s，range ＝σ s，max -σ s，min
in the formula, σ s，range For alternating stress range of the reinforcement, sigma s，max Maximum tensile stress of the reinforcing bar, sigma s，min The minimum tensile stress for the rebar.
Reinforcement bar in alternating stress range sigma s，range The maximum number of times N of the lower bearable load can be determined by the above-mentioned curve equation.
The judgment criterion of the steel bar safety is as follows: the ratio of the actual number of loads to the maximum number of loads N must be less than 1. The actual loading times can be provided by a fan manufacturer according to the scene of the test of the transmission chain of the wind turbine generator or the whole life cycle of the blade.
c. Anchoring device
As shown in fig. 5, the anchor 4 has four key safety check positions. And (3) simulating the load of each operation condition of the test bed by carrying out finite element analysis, extracting a calculation result to obtain stress ranges of four key safety check positions, carrying out check of the position I and the position II according to a check method universal for European standards or national standards, wherein the failure mode of the position III is concrete conical surface failure, and the failure mode of the position IV is concrete failure under the condition that the surface steel plate is pressed, so that the position III and the position IV are checked for fatigue strength according to the fatigue strength check of the steel-concrete part in the step (2).
(3) Stiffness verification
If a dynamic loading device exists in the test bed (for example, the transmission chain test bed is provided with a motor driving device or a hydraulic loading mechanism, and the blade test bed is provided with a hydraulic loading mechanism), vibration analysis needs to be carried out, modal calculation is carried out on the test bed base by using a finite element model of the test bed base, each modal frequency of the test bed is obtained, and the rotating frequency range of the rotating part is avoided.
The safety assessment method is suitable for safety assessment of a large-scale test bed foundation of the wind generating set, based on intrinsic parameters and various working condition parameters of the test bed foundation, limit loads and fatigue loads of all parts are obtained by using a finite element model, limit strength verification and fatigue strength verification are respectively carried out on all parts such as a pile leg 1, a pile foundation bearing platform 2, a supporting structure 3 and an anchoring device 4 by using a corresponding verification method, and overall vibration analysis and rigidity assessment are carried out on the test bed foundation according to actual operating conditions, so that safety assessment of the test bed foundation is realized. The safety evaluation method can be used as an instructive method aiming at the basic safety recheck of the test bed.
Example 2:
the embodiment provides a wind turbine generator system test bench based safety assessment system, and the safety assessment system comprises:
the acquisition module is used for acquiring inherent parameters of a test bed foundation and extreme working condition parameters, operation working condition parameters and earthquake working condition parameters in a whole life cycle;
the simulation module is used for substituting the extreme working condition parameters, the operating working condition parameters and the earthquake working condition parameters into a pre-constructed finite element model respectively, and performing stress simulation on the test bed foundation by using the finite element model to obtain the limit load and the fatigue load of the test bed foundation;
the checking module is used for checking the ultimate strength and the fatigue strength of the test bed foundation based on the inherent parameters, the extreme working condition parameters, the operating working condition parameters, the earthquake working condition parameters, the ultimate load and the fatigue load;
the intrinsic parameters comprise soil mechanics parameters, structural parameters and mechanical property parameters of the test bed foundation.
The check module includes:
the ultimate strength checking unit is used for checking the bearing capacity of the pile leg based on the maximum axial tensile load and the maximum axial compressive load of the pile leg;
and the fatigue strength checking unit is used for checking the fatigue strength of a reinforced concrete part of the test bed foundation based on the maximum compressive stress and the minimum compressive stress of the concrete and the maximum tensile stress and the minimum tensile stress of the reinforcing steel bar, and the reinforced concrete part comprises a pile foundation bearing platform, an anchoring device and a supporting structure on the upper part of the pile foundation bearing platform.
The safety evaluation system further comprises a rigidity checking module which is used for carrying out modal calculation on the test bed foundation by using the finite element model to obtain the modal frequency of the test bed foundation, comparing the modal frequency with the rotating frequency range of the wind turbine generator to be tested and checking the rigidity of the test bed foundation.
The safety evaluation system also comprises a finite element modeling module which is used for building a finite element model of the pile foundation bearing platform and the supporting structure by adopting the shell unit, building a finite element model of the pile leg by adopting the beam unit, setting the boundary condition of the finite element model of the pile leg, and building a finite element model of the foundation of the test bed by using the finite element models and the boundary condition of the components.
Example 3:
based on the same inventive concept, the present invention also provides a computer device comprising a processor and a memory for storing a computer program comprising program instructions, the processor being configured to execute the program instructions stored by the computer memory. The Processor may be a Central Processing Unit (CPU), or may be other general purpose Processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), an off-the-shelf Programmable gate array (FPGA) or other Programmable logic device, a discrete gate or transistor logic device, a discrete hardware component, etc., which is a computing core and a control core of the terminal, and is specifically adapted to implement one or more instructions, and specifically adapted to load and execute one or more instructions in a computer storage medium so as to implement a corresponding method flow or a corresponding function, so as to implement the steps of the safety assessment method based on the wind turbine generator test bed in embodiment 1.
Example 4:
based on the same inventive concept, the present invention further provides a storage medium, in particular, a computer-readable storage medium (Memory), which is a Memory device in a computer device and is used for storing programs and data. It is understood that the computer readable storage medium herein can include both built-in storage media in the computer device and, of course, extended storage media supported by the computer device. The computer-readable storage medium provides a storage space storing an operating system of the terminal. Also, one or more instructions, which may be one or more computer programs (including program code), are stored in the memory space and are adapted to be loaded and executed by the processor. It should be noted that the computer-readable storage medium may be a high-speed RAM memory, or may be a non-volatile memory (non-volatile memory), such as at least one disk memory. The processor may load and execute one or more instructions stored in the computer-readable storage medium to implement the steps of the wind turbine generator system test bed-based security assessment method in embodiment 1.
As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
The present invention is not limited to the above embodiments, and any modifications, equivalent substitutions, improvements, etc. within the spirit and principle of the present invention are included in the scope of the claims of the present invention.
Claims (20)
1. A safety assessment method for a wind turbine generator system test bed foundation is characterized by comprising the following steps:
acquiring inherent parameters of the test bed foundation and extreme working condition parameters, operation working condition parameters and earthquake working condition parameters in the whole life cycle;
respectively substituting the extreme working condition parameters, the operating working condition parameters and the earthquake working condition parameters into a pre-constructed finite element model, and performing stress simulation on the test bed foundation by using the finite element model to obtain the limit load and the fatigue load of the test bed foundation;
performing limit strength check and fatigue strength check on the test bed foundation based on the inherent parameters, the extreme working condition parameters, the operating working condition parameters, the earthquake working condition parameters, the limit load and the fatigue load;
wherein the intrinsic parameters comprise soil mechanical parameters, structural parameters and mechanical property parameters of the test bed foundation.
2. The safety assessment method of claim 1, wherein said limit loads comprise maximum axial tensile and maximum axial compressive loads of the leg, and said fatigue loads comprise maximum and minimum compressive stresses of the concrete and maximum and minimum tensile stresses of the rebar.
3. The safety assessment method of claim 2, wherein said performing an extreme strength check and a fatigue strength check on said test rig foundation based on said extreme condition parameters, operating condition parameters, seismic condition parameters, extreme loads, and fatigue loads comprises:
checking the bearing capacity of the pile leg based on the maximum axial tensile load and the maximum axial compressive load of the pile leg;
and checking the fatigue strength of the reinforced concrete part of the test bed foundation based on the maximum compressive stress and the minimum compressive stress of the concrete and the maximum tensile stress and the minimum tensile stress of the reinforcing steel bar, wherein the reinforced concrete part comprises a pile foundation pile cap, a supporting structure on the upper part of the pile foundation pile cap and an anchoring device inside the pile foundation pile cap.
4. The safety assessment method of claim 3, wherein the load bearing verification of the leg based on the maximum axial tensile load and the maximum axial compressive load of the leg comprises:
calculating to obtain the maximum tensile bearing capacity and the maximum compressive bearing capacity of the pile leg by combining a maximum tensile bearing capacity calculation formula and a maximum compressive bearing capacity calculation formula respectively based on the soil mechanics parameters;
and respectively comparing the maximum axial tensile load and the maximum axial compressive load with the maximum tensile bearing capacity and the maximum compressive bearing capacity, wherein if the maximum axial tensile load and the maximum axial compressive load are respectively smaller than the maximum tensile bearing capacity and the maximum compressive bearing capacity, the bearing capacity of the pile leg is qualified, otherwise, the bearing capacity of the pile leg is unqualified.
5. The security assessment method of claim 4, wherein said maximum tensile load bearing capacity is calculated as follows:
in the formula, F a Is the maximum tensile bearing capacity, R, of a single pile s As side friction resistance, R b Is pile end resistance, m is tensile bearing capacity reduction coefficient, fs i Is the ultimate frictional resistance characteristic value f of the rock soil around the ith soil layer pile p Is the ultimate end resistance characteristic value, thk, of the ith soil layer pile end rock soil i The thickness of the soil layer of the ith geological section is shown, D is the diameter of the pile leg, and n is the total number of the soil layers of the geological section.
6. The security assessment method of claim 4, wherein said maximum compressive load bearing capacity is calculated as follows:
in the formula, F a ' maximum compressive load bearing capacity of a monopile, R s As side friction resistance, R b Is pile end resistance, c is compression bearing capacity reduction coefficient, fs i Is the ultimate frictional resistance characteristic value f of the rock soil around the ith soil layer pile p Is the ultimate end resistance characteristic value, thk, of the ith soil layer pile end rock soil i The thickness of the soil layer of the ith geological section is shown, D is the diameter of the pile leg, and n is the total number of the soil layers of the geological section.
7. The safety assessment method of claim 3, wherein said checking the fatigue strength of the steel-concrete portion of the test bed foundation based on the maximum and minimum compressive stresses of the concrete and the maximum and minimum tensile stresses of the steel reinforcement comprises:
calculating to obtain the maximum load times of the concrete under the alternating stress based on the maximum compressive stress and the minimum compressive stress of the concrete and the maximum load time calculation formula of the concrete, and calculating to obtain the maximum load times of the reinforcing steel bar under the alternating stress based on the maximum tensile stress and the minimum tensile stress of the reinforcing steel bar and the S-N curve formula of the reinforcing steel bar;
if the ratio of the actual loading times of the concrete to the maximum loading times which can be borne by the concrete and the ratio of the actual loading times of the reinforcing steel bars to the maximum loading times which can be borne by the reinforcing steel bars are both smaller than 1, the fatigue strength of the reinforced concrete structure is qualified, otherwise, the fatigue strength of the reinforced concrete structure is unqualified.
8. The safety evaluation method according to claim 7, wherein the maximum number of times of loading of concrete is calculated as follows:
in the formula, N 1 The maximum number of times of load that the concrete can bear under alternating stress, E cd，max Is the maximum compressive stress level, R, of the concrete i The stress ratio of the concrete is shown.
9. The security evaluation method of claim 7, wherein the curve formula is represented by the following formula:
wherein, delta sigma is amplitude of alternating stress, N is maximum load times of the steel bar under the alternating stress, and N is * Is 10 6 K1 and k2 are logN on S-N curve of reinforcing steel bar respectively * Corresponding to the slope of the curve on both sides of the position.
10. The security assessment method of claim 1, wherein the security assessment method further comprises:
carrying out modal calculation on the test bed foundation by using the finite element model to obtain the modal frequency of the test bed foundation;
and comparing the modal frequency with the rotating frequency range of the wind turbine generator to be tested, if the modal frequency falls within the rotating frequency range, determining that the rigidity of the test bed foundation is unqualified, otherwise, determining that the rigidity of the test bed foundation is qualified.
11. The security assessment method of claim 3, wherein said security assessment method further comprises:
establishing a finite element model of the pile foundation bearing platform and the supporting structure by adopting a shell unit, and establishing a finite element model of the pile leg by adopting a beam unit;
setting boundary conditions for the finite element model of the pile leg, wherein the boundary conditions comprise a horizontal stiffness coefficient, a vertical stiffness coefficient and a rotational stiffness coefficient;
and constructing the finite element model of the test bed foundation by the finite element models of the pile foundation cap and the supporting structure, the finite element model of the pile leg and the boundary conditions.
12. The safety assessment method of claim 11, wherein said setting boundary conditions for a finite element model of said leg comprises:
and respectively setting the horizontal stiffness coefficient, the vertical stiffness coefficient and the rotational stiffness coefficient by combining a horizontal stiffness coefficient formula, a pile end vertical stiffness coefficient formula and a rotational stiffness coefficient formula based on the structural parameters and the mechanical property parameters of the pile legs.
13. The security assessment method of claim 12, wherein said horizontal stiffness coefficient is represented by the following formula:
wherein, K h The horizontal stiffness coefficient is arranged along the length of the pile, L is the buried depth length of the pile leg, T is the elastic length, EI is the bending stiffness, E is the elastic modulus, and I is the section moment of inertia.
14. The security assessment method of claim 12, wherein said pile tip vertical stiffness coefficient is represented by the following formula:
wherein, K v Is the pile tip vertical stiffness coefficient, N p For the vertical compressive load borne by the pile, s is the vertical compressive load subsidence value borne by the pile, Q h For settling loads, L c In order to calculate the length of the strip,d is the diameter of the pile leg, A is the net area of the pile section, and E is the elastic modulus.
15. The security assessment method of claim 12, wherein said rotational stiffness coefficient is represented by the following formula:
wherein, K θ The coefficient of rotational stiffness is L, the length of the embedded depth of the pile leg is T, the elastic length is T, EI is bending stiffness, E is elastic modulus, and I is the section moment of inertia.
16. The security assessment method of claim 11, wherein said shell element is a 4-node.
17. The utility model provides a wind turbine generator system test bench based safety assessment system which characterized in that, this safety assessment system includes:
the acquisition module is used for acquiring intrinsic parameters of the test bed foundation and extreme working condition parameters, operation working condition parameters and earthquake working condition parameters in the whole life cycle;
the simulation module is used for substituting the extreme working condition parameters, the operating working condition parameters and the earthquake working condition parameters into a pre-constructed finite element model respectively, and performing stress simulation on the test bed foundation by using the finite element model to obtain the limit load and the fatigue load of the test bed foundation;
the checking module is used for checking the ultimate strength and the fatigue strength of the test bed foundation based on the inherent parameters, the extreme working condition parameters, the operating working condition parameters, the earthquake working condition parameters, the ultimate load and the fatigue load;
wherein the intrinsic parameters comprise soil mechanical parameters, structural parameters and mechanical property parameters of the test bed foundation.
18. The security assessment system of claim 17, wherein the verification module comprises:
the ultimate strength checking unit is used for checking the bearing capacity of the pile leg based on the maximum axial tensile load and the maximum axial compressive load of the pile leg;
and the fatigue strength checking unit is used for checking the fatigue strength of the reinforced concrete part of the test bed foundation based on the maximum compressive stress and the minimum compressive stress of the concrete and the maximum tensile stress and the minimum tensile stress of the steel bar, and the reinforced concrete part comprises a pile foundation bearing platform, an anchoring device and a supporting structure on the upper part of the pile foundation bearing platform.
19. A computer device, comprising: one or more processors; the processor to store one or more programs; the one or more programs, when executed by the one or more processors, implement a wind turbine farm-based safety assessment method of any of claims 1-16.
20. A computer-readable storage medium, on which a computer program is stored which, when executed, implements a wind turbine foundation safety assessment method according to any of claims 1-16.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211194955.6A CN115828359A (en) | 2022-09-27 | 2022-09-27 | Safety assessment method, system, equipment and medium for wind power test bed foundation |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211194955.6A CN115828359A (en) | 2022-09-27 | 2022-09-27 | Safety assessment method, system, equipment and medium for wind power test bed foundation |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115828359A true CN115828359A (en) | 2023-03-21 |
Family
ID=85524174
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211194955.6A Pending CN115828359A (en) | 2022-09-27 | 2022-09-27 | Safety assessment method, system, equipment and medium for wind power test bed foundation |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115828359A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116090138A (en) * | 2023-04-03 | 2023-05-09 | 浙江远算科技有限公司 | Hydraulic turbine runner fatigue simulation calculation method and system based on data monitoring |
| CN116423527A (en) * | 2023-06-12 | 2023-07-14 | 之江实验室 | Construction method and device of mechanical arm, storage medium and electronic equipment |
-
2022
- 2022-09-27 CN CN202211194955.6A patent/CN115828359A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116090138A (en) * | 2023-04-03 | 2023-05-09 | 浙江远算科技有限公司 | Hydraulic turbine runner fatigue simulation calculation method and system based on data monitoring |
| CN116423527A (en) * | 2023-06-12 | 2023-07-14 | 之江实验室 | Construction method and device of mechanical arm, storage medium and electronic equipment |
| CN116423527B (en) * | 2023-06-12 | 2023-09-01 | 之江实验室 | Construction method and device of mechanical arm, storage medium and electronic equipment |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Wang et al. | Feasibility study of offshore wind turbines with hybrid monopile foundation based on centrifuge modeling | |
| Wang et al. | Lateral bearing capacity of hybrid monopile-friction wheel foundation for offshore wind turbines by centrifuge modelling | |
| CN115828359A (en) | Safety assessment method, system, equipment and medium for wind power test bed foundation | |
| CN107894311A (en) | The model test method of earth and rockfill dam eaerthquake damage | |
| Goktepe et al. | Numerical and experimental study on scaled soil-structure model for small shaking table tests | |
| Ma et al. | Scour protection assessment of monopile foundation design for offshore wind turbines | |
| US6349590B1 (en) | Method and apparatus for estimating load bearing capacity of piles | |
| Li et al. | Drainage conditions around monopiles in sand | |
| Pisanò et al. | Input of fully 3D FE soil-structure modelling to the operational analysis of jack-up structures | |
| Vlahos et al. | Numerical simulation of pushover tests on a model jack-up platform on clay | |
| Li et al. | The loading behavior of innovative monopile foundations for offshore wind turbine based on centrifuge experiments | |
| Jiang et al. | Soil damping calculation of the offshore wind turbine supported by wide-shallow bucket foundation | |
| Ibsen et al. | Design of a new foundation for offshore wind turbines | |
| CN209907452U (en) | Simplified test model of steel pipe pile under vibration condition | |
| Zachert et al. | Simulation of a full-scale test on a gravity base foundation for offshore wind turbines using a high cycle accumulation model | |
| Tolun et al. | Dynamic response of a single pile embedded in sand including the effect of resonance | |
| Li et al. | Experimental and two-scale numerical studies on the behavior of prestressed concrete-steel hybrid wind turbine tower models | |
| Ma et al. | Effect of long-term lateral cyclic loading on the dynamic response and fatigue life of monopile-supported offshore wind turbines | |
| Tabeshpour | Nonlinear dynamic analysis of chimney-like towers | |
| Ali et al. | The Performance of Helical Pile under Cyclic Load Using 3D-Finite Element Analysis | |
| Alegre et al. | Seismic analysis of Cabril dam. Measured response and comparison with numerical results from Code_Aster and DamDySSA | |
| Liang et al. | Analysis of Cumulative Damage Characteristics of Long Spiral Belled Pile under Horizontal Cyclic Loading at Sea | |
| Alizadeh | Numerical Analysis to Investigate the Static and Dynamic Performance of GRS Bridge Abutments | |
| CN114279827B (en) | Method for obtaining tunnel damping layer material | |
| Abdel-Rahman et al. | Behavior of foundation piles for offshore wind energy plants under axial cyclic loading |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication |