A method for analyzing response of a power tower coupled with a tower crane under sea wind load

Abstract

The application discloses a kind of offshore wind load effect under power tower and tower machine coupling body response analysis method, comprising the following steps: S1, power tower and tower machine coupling body multidimensional modeling, S2, to three-dimensional model is judged mechanically transmitted, S3, to hoist whole process working condition is simulated, S4, power tower and tower machine coupling body stress monitoring and early warning, S5, based on Unity3D engine constructs virtual command cabin, integrates real-time sensor data and simulation result, dynamically adjusts hoisting path, S6, is combined with transmission tower tower machine coupling system finite element model, the dynamic amplification effect under wind-induced vibration is analyzed;S7, based on ANSYS Workbench compares the stress distribution before and after split component, ensure that the stress of steel pipe drops after counterweight;Using unmanned aerial vehicle laser scanning point cloud data vs simulation deformation result, error is controlled in small range. Comprehensive, accurately analyze the response of power tower and tower machine coupling body under the action of offshore wind load, provide scientific basis and safety guarantee for power tower hoisting construction.

Description

Technical Field

[0001] This invention belongs to the field of power equipment technology, specifically, it relates to a method for analyzing the response of a power tower and tower crane coupling under offshore wind load. Background Technology

[0002] A power transmission tower system consists of transmission towers, conductors, and insulators, with the transmission tower being the main load-bearing structure supporting the transmission line. A transmission tower typically comprises the tower body, platforms, stairs, and auxiliary facilities. Conductors run through the conductor channels between transmission towers, bearing the electrical load and transmitting power. Insulators provide support and insulation.

[0003] Ultra-high voltage (UHV) transmission line projects utilize steel pipe towers with large structural dimensions, long crossarms, and large components, significantly increasing the difficulty of tower erection. Traditional internally suspended externally guyed gantry systems are heavily influenced by terrain conditions and cannot meet the erection requirements of these crossing towers. Current technology using double-arm ground-mounted gantry systems for tower dismantling and erection involves a power tower that is a long, slender, and large mechanical model with an unfixed upper end. The ground-mounted gantry system, attached to the power tower, creates coupling effects, resulting in significant deviations from actual performance when performing individual safety and stability calculations.

[0004] Treating the power transmission tower and its supporting pylon as a whole and studying their coupled influence is crucial for improving the accuracy of system mechanics analysis. Furthermore, sea-level wind speeds are high and wind conditions are highly variable and complex. Long-span towers have extremely high tower heights, and wind speeds vary rapidly along the tower's height. The displacement response of transmission tower lines under wind loads is influenced by many factors, primarily including the following:

[0005] (1) Wind load characteristics:

[0006] Influencing factors include wind speed, wind direction, and duration of wind action.

[0007] (2) Structural characteristics:

[0008] This includes transmission tower structural parameters, material properties, and construction methods.

[0009] (3) Foundation conditions:

[0010] This includes factors such as foundation bearing capacity, groundwater level, and foundation type.

[0011] Because the formation and characteristics of wind load at the construction site are unclear, it is impossible to correctly evaluate the safety of the double-arm ground-mounted pole.

[0012] Therefore, conducting research on the response and impact of double-arm ground-mounted derricks under unconventional wind loads will play a crucial role in ensuring construction safety and completing the construction schedule on time. Summary of the Invention

[0013] To address the shortcomings of existing technologies, the present invention aims to provide a method for analyzing the response of a power tower and tower crane coupling under offshore wind loads.

[0014] To achieve the aforementioned objectives, the technical solution adopted by this invention includes: a method for analyzing the response of a power tower and tower crane coupling under offshore wind loads, which involves collecting design drawings, material specifications, structural parameters, and other data of the power tower and tower crane, and includes the following steps:

[0015] S1. Based on the collected data, a multi-dimensional model of the coupling between the power tower and the tower crane is created, including:

[0016] S1.1. Based on Tekla Structure, establish a three-dimensional model of the power tower and tower crane, collect the geometric features of irregular components, accurately capture the spatial morphology of complex structures (crossarms / tower heads), set parameters for component material properties, cross section moment of inertia, and connection node stiffness, define the constitutive relationship of steel, quantify the bending stiffness of components, distinguish the force transmission characteristics (axial / shear / rotational stiffness) of bolt / welded / hinged nodes, and simulate the stress points in order to obtain buckling load and buckling mode.

[0017] S1.2 Finite element discretization modeling: In the power tower, Beam188 beam elements are used to simulate the main members, simulating their bending performance and calculating their flexural deformation. Link180 bar elements are used to simulate the diagonal members, simulating their tensile and compressive behavior and characterizing their axial force characteristics. Node degrees of freedom are coupled. In the tower crane, Shell181 shell elements are used for the boom to calculate local buckling and capture in-plane / out-of-plane stresses in the thin-walled structure. Link10 cable elements are used for the cable to calculate the oscillation amplitude of the suspended load and simulate the nonlinear large deformation of the cable. The coupling body of the power tower and tower crane is determined by constraint equations to connect the tower crane lifting point and the power tower lifting point, establishing the displacement coordination relationship between the tower crane lifting point and the power tower node: u_lifting_point = u_node + Rθ, simulating the force transmission path.

[0018] S2. Perform mechanical transfer judgment on the 3D model, including:

[0019] S2.1 The power transmission path analysis of the power tower adopts the static equilibrium equation. ,in To balance the counterweight, The support reaction force is given by Wmax, the maximum lifting weight is given by a, and the counterweight is given by α. The horizontal distance to the fulcrum b, where b is the support reaction force. The horizontal distance to fulcrum b, For the weight of the power tower itself, Set the center of gravity offset for the lever arm with the maximum lifting capacity. Foundation settlement threshold ≤ 5mm

[0020] S2.2 Analysis of the tower crane's force transmission path, setting the dynamic equations of the tower crane's force transmission mechanism and slings: Where θ is the cable inclination angle, u is the displacement oscillation, w is the suspended weight, and m is the suspended weight mass. Let g be the tension of the sling, g be the acceleration due to gravity, and u be the displacement oscillation. Let be the acceleration, where θ is the cable inclination angle, calculate the cable tension under dynamic load, and u is the displacement oscillation. Then, optimize the swing amplitude of the suspended load to accurately predict the instantaneous impact load during lifting.

[0021] Tower crane mechanical stability criterion equation: Tower crane dynamic stability criterion equation: Where ε: wind vibration coefficient 1.2-1.5, Fsway: yaw force, Wi: various stable loads, di: stress arm, H: height of the wind load application point. : Wind load, L: lever arm of the yaw force;

[0022] S3. Simulate the entire hoisting process, including:

[0023] S3.1. Based on ANSYS Mechanical APDL, a time-varying load function library is established for the tower crane base during the lifting phase, the ball hinge constraint at the lifting point during the translation phase, and the spring-damped foundation during the positioning phase. This accurately simulates the dynamic load characteristics of the three phases. The tower crane base is fixed in the initial lifting state, the ball hinge constraint at the lifting point releases the translational degree of freedom, and the spring-damped foundation simulates the interaction between the power tower foundation and the soil, fitting the component positioning collision effect.

[0024] S3.2. Set the dynamic control algorithm and solve the equations of motion:

[0025] Where M is the mass matrix and C is the damping matrix. For acceleration, For speed, For displacement vectors, The external force vector; and a multibody coupling algorithm based on the Lagrange multiplier method to handle tower crane-power tower contact collisions, which efficiently solves transient dynamics problems, eliminates the computational burden of matrix inversion, controls numerical oscillations, strictly satisfies the non-penetration condition of contact, and automatically adjusts according to the material hardness;

[0026] S4. Stress monitoring and early warning of the coupling body between power tower and tower crane, including:

[0027] S4.1 Establish a real-time stress monitoring model based on ANSYS, set up a critical point sensor in ANSYS, and output the Mises stress. A comprehensive assessment of the failure risk under multiaxial stress conditions was conducted, and a safety threshold was set: the yield strength of the steel. Allowable stress It can detect signs of crack initiation in advance, which is more efficient than full-area monitoring.

[0028] S4.2 Tower instability early warning setting: if it is detected... Or a displacement of L / 400, where L is the span, triggers a level 3 warning. The level 3 warning includes:

[0029] a) Automatically reduce hoisting speed, b) Adjust counterweight position, c) Emergency braking, covering most accident causes, while monitoring strength and stiffness failures and initiating corresponding measures according to the risk level.

[0030] S5. A virtual command cabin is built based on the Unity3D engine, integrating real-time sensor data and simulation results to dynamically adjust the hoisting path. To address the issue of center-of-gravity shift in irregularly shaped components, the position of the counterweight is optimized through iterative calculation. Where d is the length of the counterweight arm, This is the offset of the center of gravity. It is a lifting load, a three-dimensional real-time mapping of the entire lifting process, automatic correction of the lifting trajectory based on displacement deviation δ, quantification of the asymmetry of irregular components, avoidance of collision risk points, coverage of secondary effects ignored by traditional models, reduction of accident probability, and construction of a digital twin model throughout the entire life cycle.

[0031] S6. Combining the finite element model of the transmission tower and tower crane coupling system, analyze the dynamic amplification effect under wind-induced vibration, simulate the impact of conductor galloping on the tower, generate the time history curve of pulsating wind load, and quantify the wind vibration effect.

[0032] S7. Based on ANSYS Workbench, compare the stress distribution before and after component disassembly to ensure that the stress of the steel pipe decreases after counterweighting; use UAV laser scanning point cloud data vs. simulation deformation results to control the error within a small range, quantitatively evaluate the effectiveness of the counterweighting scheme, and use UAV to obtain the actual deformation of the structure after construction to replace high-risk manual inspection.

[0033] Furthermore, in step S1.2, the main material stiffness matrix EI is the bending stiffness, L is the length of the main material, and φ is the displacement function; the coupling equation of the degree of freedom of the Link180 element node of the inclined material is u_tower crane lifting point = u_power tower node + Rθ_tower crane, where R is the slewing radius of the sling and θ is the pitch angle of the tower crane boom.

[0034] Furthermore, in step 3.2, the constraint equations for the coupling body of the power tower and the tower crane are established using the Lagrange multiplier method: ( ), where λ is the contact force, δ is the displacement, and Kc is the contact stiffness matrix, with values ​​ranging from 10⁸ to 10¹⁰ N / m.

[0035] Furthermore, step 2.1 also includes power tower force transmission path tracing, based on a force flow algorithm derived from stiffness matrix decomposition. , It is the global stiffness matrix of the entire power tower structure. It is the external force applied to the lifting points during hoisting. These are the reaction forces or internal forces at each node; the critical path output is: suspension point → crossarm → main material → foundation.

[0036] Furthermore, the hazard point sensors in step 4.1 include the tower crane boom root and the power tower node plate.

[0037] Compared with the prior art, the advantages of the present invention include:

[0038] By employing multi-dimensional modeling, mechanical transmission judgment, working condition simulation, stress monitoring and early warning, virtual command cabin construction, wind-induced vibration analysis, and effectiveness evaluation of counterweight schemes, this approach overcomes the challenges of traditional models, enabling a shift in power tower hoisting safety control from "post-event remediation" to "pre-event prevention." This propels power construction into the digital twin era, improves the accuracy of equipment maintenance and management, predicts equipment failures and bottlenecks, facilitates preventative maintenance, reduces downtime, optimizes production processes and resource allocation, lowers production costs, and increases production efficiency. Detailed Implementation

[0039] In view of the shortcomings of the prior art, the inventors of this invention, through long-term research and extensive practice, have proposed the technical solution of this invention. The technical solution, its implementation process, and principles are further explained below.

[0040] It should be noted that the following embodiments are exemplary and only used to explain the present invention, and should not be construed as limiting the present invention. The described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, the present invention covers any substitutions, modifications, equivalent methods and solutions made on the spirit, principles and scope of the present invention as defined by the claims. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] In the description of this application, the terms "first," "second," "third," and similar words do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms "a" or "one," and similar words, do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms "comprising" or "including," and similar words, mean that the elements or objects preceding "comprising" or "including" encompass the elements or objects listed following "comprising" or "including," and their equivalents, but do not exclude other elements or objects. The terms "connected" or "linked," and similar words, are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect.

[0042] In the description of this application, the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," indicating orientation or positional relationships, are used only for the convenience of describing this application and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, when using positional terms such as sides, outer side, and upper and lower, it should be understood that they are used only for ease of understanding and description, taking into account that the structure may be oriented to other positions.

[0043] In the description of this application, unless otherwise expressly specified and limited, the technical or scientific terms used shall have the ordinary meaning understood by a person with ordinary skills in the art to which this application pertains. Terms such as “installation,” “connection,” and “joining” shall be interpreted broadly, for example, as fixed connection, detachable connection, mating connection, or integral connection. For a person skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0044] The present invention aims to introduce and explain the structural composition and the coordination relationship between the components of a power tower and tower crane coupling body response analysis method under offshore wind load. Unless otherwise specified, the dimensions, materials and manufacturing processes of each component in the present invention suitable for the response analysis method of power tower and tower crane coupling body under offshore wind load can be selected according to specific circumstances, and no special limitations or explanations are made here.

[0045] Furthermore, to provide the public with a better understanding of the present invention, certain specific details are described in detail in the following description of the invention. However, those skilled in the art will fully understand the invention even without these detailed descriptions.

[0046] Example 1

[0047] A method for analyzing the response of a power tower and tower crane coupling under offshore wind loads involves collecting design drawings, material specifications, and structural parameters of the power tower and tower crane, including the following steps:

[0048] S1. Based on the collected data, a multi-dimensional model of the coupling between the power tower and the tower crane is created, including:

[0049] S1.1. Based on Tekla Structure, establish a three-dimensional model of the power tower and tower crane, collect the geometric features of irregular components, accurately capture the spatial morphology of complex structures (crossarms / tower heads), set parameters for component material properties, cross section moment of inertia, and connection node stiffness, define the constitutive relationship of steel, quantify the bending stiffness of components, distinguish the force transmission characteristics (axial / shear / rotational stiffness) of bolt / welded / hinged nodes, and simulate the stress points in order to obtain buckling load and buckling mode.

[0050] S1.2 Finite element discretization modeling: In the power tower, Beam188 beam elements are used to simulate the main members, simulating their bending performance and calculating their flexural deformation. Link180 bar elements are used to simulate the diagonal members, simulating their tensile and compressive behavior and characterizing their axial force characteristics. Nodal degrees of freedom are coupled. In the tower crane, Shell181 shell elements are used for the boom to calculate local buckling and capture in-plane / out-of-plane stresses in thin-walled structures. Link10 cable elements are used for the cables to calculate the oscillation amplitude of the suspended load and simulate the nonlinear large deformation of the cables. The coupling between the power tower and the tower crane is determined by constraint equations, connecting the crane lifting point and the power tower lifting point. The displacement coordination relationship between the crane lifting point and the power tower nodes is established: u_lifting_point = u_node + Rθ, simulating the force transmission path. Main member stiffness matrix. EI is the bending stiffness, L is the length of the main material, and φ is the displacement function; the coupling equation of the degree of freedom of the Link180 element node of the inclined material is u_tower crane lifting point = u_power tower node + Rθ_tower crane, where R is the slewing radius of the sling and θ is the pitch angle of the tower crane boom.

[0051] A three-in-one modeling system integrating irregular components, node coupling, and dynamic force transmission was established to overcome two major industry challenges in power tower hoisting: "local stress distortion" and "fracture of coupled force transmission path," providing a digital foundation for safe construction of ultra-high voltage projects.

[0052] S2. Perform mechanical transfer judgment on the 3D model, including:

[0053] S2.1 The power transmission path analysis of the power tower adopts the static equilibrium equation. ,in To balance the counterweight, The support reaction force is given by Wmax, the maximum lifting weight is given by a, and the counterweight is given by α. The horizontal distance to the fulcrum b, where b is the support reaction force. The horizontal distance to fulcrum b, For the weight of the power tower itself, Set the center of gravity offset for the lever arm with the maximum lifting capacity. The system includes a foundation settlement threshold of ≤5mm, quantifies the torque balance relationship of the power tower during hoisting, corrects the actual center of gravity position of irregularly shaped components, constrains foundation deformation, and also includes power tower force transmission path tracking and a force flow algorithm based on stiffness matrix decomposition. , It is the global stiffness matrix of the entire power tower structure. It is the external force applied to the lifting points during hoisting. These are the reaction forces or internal forces at each node; the critical path output is: suspension point → crossbeam → main material → foundation;

[0054] S2.2 Analysis of the tower crane's force transmission path, setting the dynamic equations of the tower crane's force transmission mechanism and slings: Where θ is the cable inclination angle, u is the displacement oscillation, w is the suspended weight, and m is the suspended weight mass. Let g be the tension of the sling, g be the acceleration due to gravity, and u be the displacement oscillation. Let be the acceleration; where θ is the cable inclination angle, calculate the cable tension under dynamic load, and u is the displacement oscillation. Then, optimize the swing amplitude of the suspended load to accurately predict the instantaneous impact load during lifting.

[0055] Tower crane mechanical stability criterion equation: Tower crane dynamic stability criterion equation: Where ε: wind vibration coefficient 1.2-1.5, Fsway: yaw force, Wi: various stable loads, di: stress arm, H: height of the wind load application point. : Wind load, L: lever arm of the yaw force;

[0056] S3. Simulate the entire hoisting process, including:

[0057] S3.1. Based on ANSYS Mechanical APDL, a time-varying load function library is established for the tower crane base during the lifting phase, the ball hinge constraint at the lifting point during the translation phase, and the spring-damped foundation during the positioning phase. This accurately simulates the dynamic load characteristics of the three phases. The tower crane base is fixed in the initial lifting state, the ball hinge constraint at the lifting point releases the translational degree of freedom, and the spring-damped foundation simulates the interaction between the power tower foundation and the soil, fitting the component positioning collision effect.

[0058] S3.2. Set the dynamic control algorithm and solve the equations of motion:

[0059] Where M is the mass matrix and C is the damping matrix. For acceleration, For speed, For displacement vectors, The external force vector; and a multi-body coupling algorithm based on the Lagrange multiplier method for handling tower crane-power tower contact collisions, where the coupling bodies of the tower crane and the power tower are constrained by the Lagrange multiplier method: ( ), where λ is the contact force, δ is the displacement, Kc: contact stiffness matrix, with values ​​ranging from 108 to 1010 N / m, efficiently solves transient dynamic problems, eliminates the computational burden of matrix inversion, controls numerical oscillations, strictly satisfies the non-penetrating contact condition, and automatically adjusts according to the material hardness;

[0060] It pioneered a time-varying load-constraint linkage mechanism, dynamically matching the load function library with boundary conditions (such as automatically switching ball joint constraints during translation), solving the stress distortion problem caused by "load-constraint mismatch" in traditional simulations; the simultaneous solution of the Lagrange multiplier method and explicit integral overcomes the collision oscillation problem, improving the efficiency of contact force calculation.

[0061] S4. Stress monitoring and early warning of the coupling body between power tower and tower crane, including:

[0062] S4.1 Establish a real-time stress monitoring model based on ANSYS, set up a critical point sensor in ANSYS, and output the Mises stress. A comprehensive assessment of the failure risk under multiaxial stress conditions was conducted, and a safety threshold was set: the yield strength of the steel. Allowable stress Early detection of crack initiation signs improves efficiency compared to full-area monitoring. Hazard point sensors include those installed at the base of the tower crane boom and at the node plate of the power tower.

[0063] S4.2 Tower instability early warning setting: if instability is detected... Or a displacement of L / 400, where L is the span, triggers a level 3 warning. The level 3 warning includes:

[0064] a) Automatically reduce hoisting speed, b) Adjust counterweight position, c) Emergency braking, covering most accident causes, while monitoring strength and stiffness failures and initiating corresponding measures according to the risk level.

[0065] Step S4 can automatically adjust the displacement threshold with the span L, update the allowable stress according to the steel batch, and perform stress monitoring → hoisting speed control → counterweight optimization → emergency braking. The entire chain is automated, realizing a revolutionary transformation of power tower hoisting safety control from "post-event remediation" to "pre-event prevention", providing all-weather protection for UHV construction.

[0066] S5. A virtual command cabin is built based on the Unity3D engine, integrating real-time sensor data and simulation results to dynamically adjust the hoisting path. To address the issue of center-of-gravity shift in irregularly shaped components, the position of the counterweight is optimized through iterative calculation. Where d is the length of the counterweight arm, This is the offset of the center of gravity. It is a lifting load, a three-dimensional real-time mapping of the entire lifting process, automatic correction of the lifting trajectory based on displacement deviation δ, quantification of the asymmetry of irregular components, avoidance of collision risk points, coverage of secondary effects ignored by traditional models, reduction of accident probability, and construction of a digital twin model throughout the entire life cycle.

[0067] S6. Combining the finite element model of the transmission tower and tower crane coupling system, analyze the dynamic amplification effect under wind-induced vibration, simulate the impact of conductor galloping on the tower, generate the time history curve of pulsating wind load, and quantify the wind vibration effect.

[0068] S7. Based on ANSYS Workbench, compare the stress distribution before and after component disassembly to ensure that the stress of the steel pipe decreases after counterweighting; use UAV laser scanning point cloud data vs. simulation deformation results to control the error within a small range, quantitatively evaluate the effectiveness of the counterweighting scheme, and use UAV to obtain the actual deformation of the structure after construction to replace high-risk manual inspection.

[0069] In this invention, steps S1-S4, based on the geometric capture of irregular components and intelligent node stiffness assignment of Tekla Structure, combined with the discretization of beam-rod-shell-cable hybrid units, overcome the problems of "stress distortion" and "force transmission path fracture" in traditional models. The time-varying load function library covers the three stages of lifting acceleration, translational sway, and positioning impact. It integrates the explicit central difference method and the Lagrange multiplier contact algorithm, and triggers a three-level response (deceleration / counterweight / braking) with dual threshold early warning, realizing a revolutionary transformation of power tower hoisting safety control from "post-event remediation" to "pre-event prevention".

[0070] In this invention, steps S5-S7 utilize the Unity3D command cabin to achieve "what you see is what you control," constructing a virtual twin. The β coefficient quantifies the once-in-a-century wind load effect to construct wind vibration defense, thus building a full-chain intelligent method for power tower hoisting: "perception-decision-execution-verification." This propels power construction into the digital twin era, enabling real-time data acquisition and analysis. It allows for real-time monitoring and analysis of equipment operating status, improving the accuracy of equipment maintenance and management, predicting equipment failures and bottlenecks, conducting preventative maintenance, reducing downtime, optimizing production processes and resource allocation, lowering production costs, and improving production efficiency.

[0071] Working principle: Collect design drawings, material specifications, structural parameters, and other information for power towers and tower cranes;

[0072] Using Tekla Structure software, three-dimensional models of power towers and tower cranes were created based on collected data. The geometric features of irregularly shaped components, such as the spatial morphology of complex crossarms and tower heads, were accurately captured. Simultaneously, parameters were set for the material properties of the components (such as the elastic modulus and Poisson's ratio corresponding to the steel grade), the moment of inertia of the cross sections, and the stiffness of connection nodes (axial, shear, and rotational stiffness of bolted, welded, and hinged nodes). The constitutive relationship of the steel was defined, the bending stiffness of the components was quantified, and the stress points were simulated, providing a basic model for subsequent analysis.

[0073] In the power tower structure, Beam188 beam elements are used to simulate the main material to calculate its flexural deformation and bending resistance; Link180 bar elements are used to simulate the diagonal material to characterize its axial stress characteristics and achieve nodal degree of freedom coupling.

[0074] The tower crane's boom uses Shell181 shell elements to calculate local buckling and capture in-plane / out-of-plane stresses in thin-walled structures; the cables use Link10 cable elements to calculate the load oscillation amplitude and simulate large nonlinear deformations of the cables.

[0075] By determining the connection between the tower crane lifting point and the power tower lifting point through constraint equations, the displacement coordination relationship between the tower crane lifting point and the power tower node is established (u_lifting_point = u_node + Rθ), where R is the slewing radius of the sling and θ is the pitch angle of the tower crane boom. A three-dimensional modeling system integrating irregular component-node coupling-dynamic force transmission is constructed.

[0076] Applying the static equilibrium equations The moment balance relationship of the power tower during hoisting is quantified. A center of gravity offset Δc and a foundation settlement threshold (≤5mm) are set to correct the actual center of gravity position of the irregularly shaped components and constrain foundation deformation. Simultaneously, a force flow algorithm based on stiffness matrix decomposition is used to track the force transmission path of the power tower and output the critical path (lifting point → crossarm → main structure → foundation).

[0077] The dynamic equations of the tower crane's force transmission mechanism and cable slings are established to calculate the cable tension under dynamic loads, optimize the swing amplitude of the suspended load, and accurately predict the instantaneous impact load during lifting. The stability of the tower crane under dynamic loads is evaluated in real time using the stability criterion equation for the tower crane's mechanical transmission (including parameters such as the wind vibration coefficient ε (1.2-1.5)) to determine whether the safety requirements are met.

[0078] Based on ANSYS Mechanical APDL software, a time-varying load function library was established for three stages: lifting, translation, and positioning. In the lifting stage, boundary conditions such as the tower crane base being fixed were set; in the translation stage, the translational degrees of freedom of the ball joint constraint at the lifting point were released; in the positioning stage, a spring-damped foundation was used to simulate the interaction between the power tower foundation and the soil, fitting the component positioning collision effect to accurately simulate the dynamic load characteristics of the three stages.

[0079] Solve the equations of motion

[0080] Where M is the mass matrix and C is the damping matrix. For acceleration, For speed, For displacement vectors, The external force vector is used. A multibody coupling algorithm based on the Lagrange multiplier method is used to handle tower crane-power tower contact collisions. A constraint equation (KcΔu=λ) is established, where Kc is the contact stiffness matrix (values ​​range from 10⁸ to 10¹⁰ N / m). This algorithm efficiently solves transient dynamic problems, eliminates the computational burden of matrix inversion, controls numerical oscillations, and strictly satisfies the non-penetration condition of the contact. Through a pioneering time-varying load-constraint linkage mechanism, the stress distortion problem caused by "load-constraint mismatch" in traditional simulations is solved. The simultaneous solution using the Lagrange multiplier method and explicit integration overcomes the collision oscillation problem and improves the efficiency of contact force calculation.

[0081] A real-time stress monitoring model was established using ANSYS software, and sensors were installed at hazardous points such as the tower crane boom root and power tower node plates. The model outputs Mises stress to comprehensively assess the failure risk under multiaxial stress conditions. A safety threshold (allowable stress corresponding to the yield strength of steel) was set to detect early signs of crack initiation. If the monitored stress exceeds the safety threshold, a timely warning is issued.

[0082] The three-level early warning system includes measures such as automatically reducing hoisting speed, adjusting counterweight position, and emergency braking, covering most accident causes. It also monitors strength and stiffness failures and initiates corresponding measures based on the risk level, realizing the transformation of power tower hoisting safety control from "post-accident remediation" to "pre-accident prevention".

[0083] A virtual command center was built using the Unity3D engine, integrating real-time sensor data and simulation results. The hoisting path was dynamically adjusted, and to address the issue of center-of-gravity shift in irregularly shaped components, the position of the counterweight was optimized through iterative calculation (dnew = dold + kΔc, where d is the counterweight arm length, Δc is the center-of-gravity shift, and k is a coefficient related to structural characteristics). The entire hoisting process was mapped in real-time in three dimensions. The hoisting trajectory was automatically corrected based on the displacement deviation δ, quantifying the asymmetry of irregularly shaped components, avoiding collision risk points, reducing the probability of accidents, and constructing a digital twin model throughout the entire lifecycle.

[0084] UAV laser scanning is used to obtain actual deformation point cloud data of the structure after construction. The data is compared with the simulation deformation results, and the error is controlled within a small range. The effectiveness of the counterweight scheme is quantitatively evaluated, replacing high-risk manual inspection.

[0085] By combining the finite element model of the transmission tower and tower crane coupling system, the dynamic amplification effect under wind-induced vibration is analyzed, the impact of conductor galloping on the tower is simulated, the time history curve of pulsating wind load is generated, and the wind vibration effect is quantified, providing a basis for subsequent safety assessment and optimization.

[0086] In this way, the method can comprehensively and accurately analyze the response of the power tower and tower crane coupling under offshore wind loads, providing a scientific basis and safety guarantee for power tower hoisting construction, promoting power construction into the digital twin era, improving construction efficiency and quality, and reducing accident risks.

[0087] It should be understood that the above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. It should not be considered that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, several simple deductions or substitutions can be made without departing from the concept of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for analyzing the response of a power tower and tower crane coupling under offshore wind loads, characterized in that, Includes the following steps: S1. Multi-dimensional modeling of the coupling between the power tower and the tower crane, including: S1.

1. Based on Tekla Structure, a 3D model of the power tower and tower crane is established, and the geometric features of the irregularly shaped components are collected. Parameters such as component material properties, section moment of inertia, and connection node stiffness are set, and stress points are simulated to obtain buckling loads and buckling modes. S1.2 Finite element discretization modeling: In the power tower, Beam188 beam elements are used to simulate the main material and calculate the bending deformation of the main material. Link180 bar elements are used to simulate the diagonal material and simulate the tensile and compressive behavior of the diagonal material. The nodal degrees of freedom are coupled. In the tower crane, Shell181 shell elements are used to calculate the local buckling of the boom. Link10 cable elements are used to calculate the oscillation amplitude of the suspended load. The coupling body of the power tower and the tower crane is determined by constraint equations to connect the lifting point of the tower crane and the lifting point of the power tower and simulate the force transmission path. S2. Perform mechanical transfer judgment on the 3D model, including: S2.1 The power transmission path analysis of the power tower adopts the static equilibrium equation. ,in To balance the counterweight, The support reaction force is given by Wmax, the maximum lifting weight is given by a, and the counterweight is given by α. The horizontal distance to the fulcrum b, where b is the support reaction force. The horizontal distance to fulcrum b, For the weight of the power tower itself, Set the center of gravity offset for the lever arm with the maximum lifting capacity. Foundation settlement threshold ≤ 5mm S2.2 Analysis of the tower crane's force transmission path, setting the dynamic equations of the tower crane's force transmission mechanism and slings: Where θ is the cable inclination angle, u is the displacement oscillation, w is the suspended weight, and m is the suspended weight mass. Let g be the tension of the sling, g be the acceleration due to gravity, and u be the displacement oscillation. For acceleration; Tower crane mechanical stability criterion equation: Tower crane dynamic stability criterion equation: Where ε: wind vibration coefficient 1.2-1.5, Fsway: yaw force, Wi: various stable loads, di: stress arm, H: height of the wind load application point. : Wind load, L: lever arm of the yaw force; S3. Simulate the entire hoisting process, including: S3.

1. Based on ANSYS Mechanical APDL, set up working condition classification and boundary conditions, and establish a time-varying load function library for the tower crane base during the lifting stage, the ball hinge constraint of the lifting point during the translation stage, and the spring-damped foundation during the positioning stage. S3.

2. Set the dynamic control algorithm and solve the equations of motion: Where M is the mass matrix and C is the damping matrix. For acceleration, For speed, For displacement vectors, This is the vector of external forces; And a multibody coupling algorithm based on the Lagrange multiplier method for handling tower crane-power tower contact collisions; S4. Stress monitoring and early warning of the coupling between power towers and tower cranes, and stress-displacement-stability synergistic analysis, including: S4.1 Establish a real-time stress monitoring model based on ANSYS, set up a critical point sensor in ANSYS, and output the Mises stress. Set a safety threshold: steel yield strength Allowable stress , S4.2 Tower instability early warning setting: if it is detected... Or a displacement of L / 400, where L is the span, triggers a level three warning, the level three warning including: a. Automatically reduce hoisting speed; b. Adjust counterweight position; c. Emergency braking. S5. A virtual command cabin is built based on the Unity3D engine, integrating real-time sensor data and simulation results to dynamically adjust the hoisting path. To address the issue of center-of-gravity shift in irregularly shaped components, the position of the counterweight is optimized through iterative calculation. Where d is the length of the counterweight arm, This is the offset of the center of gravity. It is the hoisting load; S6. Analyze the dynamic amplification effect under wind-induced vibration using the finite element model of the transmission tower crane coupling system; S7. Based on ANSYS Workbench, compare the stress distribution before and after component disassembly to ensure that the stress of the steel pipe decreases after counterweighting; use UAV laser scanning point cloud data vs. simulation deformation results to control the error within a small range.

2. The method for analyzing the response of a power tower and tower crane coupling under offshore wind loads according to claim 1, characterized in that: In step S1.2, the main material stiffness matrix EI is the bending stiffness, L is the length of the main material, and φ is the displacement function; The coupling equation of the Link180 unit node freedom of the inclined member is u_tower crane lifting point = u_power tower node + Rθ_tower crane, where R is the slewing radius of the sling and θ is the pitch angle of the tower crane boom.

3. The method for analyzing the response of a power tower and tower crane coupling under offshore wind loads according to claim 1, characterized in that: In step 3.2, the constraint equations for the coupling body of the power tower and the tower crane are established using the Lagrange multiplier method: ( ), where λ is the contact force, δ is the displacement, and Kc is the contact stiffness matrix, with values ​​ranging from 10⁸ to 10¹⁰ N / m.

4. The method for analyzing the response of a power tower and tower crane coupling under offshore wind loads as described in claim 1, characterized in that: Step 2.1 also includes power tower force transmission path tracing, based on a force flow algorithm using stiffness matrix decomposition. , It is the global stiffness matrix of the entire power tower structure. It is the external force applied to the lifting points during hoisting. It represents the reaction force or internal force at each node, and the critical path is output as follows: suspension point → crossbeam → main material → foundation.

5. The method for analyzing the response of a power tower and tower crane coupling under offshore wind loads according to claim 1, characterized in that: The hazard point sensor in step 4.1 is installed at the base of the tower crane boom and the node plate of the power tower.

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