Method for mounting flange connection, use of bolt tensioning device, computer program product, use of computer program product and storage medium

Abstract

The invention relates to a method for mounting a flange connection. The method consists of a plurality of steps. First, flange parameters of a first flange and a second flange are determined. The elongation behavior of the bolt system and the axial stiffness of the bolts and the flange body are then determined by analysis. Subsequently, in order to avoid fatigue damage, a maximum allowable gap dimension is determined. And finally, considering the gap sizes and the mounting pre-tightening force, and calculating the overall rigidity required by the flange main body. After the bolt is installed and tensioned, the reached stiffness is checked and compared to a target value.

Description

Technical Field

[0001] This invention relates to a method for installing flange connections, the use of bolt tensioning devices, computer program products, and storage media. Background Technology

[0002] In the field of flange connections, particularly for flange connections used in wind power equipment or similar structures, there is a constant need to improve the reliability, efficiency, and safety of the installation process. EP 3 593 939 A1 discloses a method and apparatus for installing flange connections. While this method is reliable and effective in many applications, challenges remain in certain aspects, such as the control of fatigue damage, precise alignment and installation of flange connections, and handling of variable clearance dimensions between flanges. Summary of the Invention

[0003] In view of the above, the object of the present invention is to provide an improved method for installing flange connections. This method is particularly effective in handling variable clearance dimensions. Furthermore, it should minimize the risk of fatigue damage, thereby optimizing the installation process.

[0004] According to the present invention, this objective is achieved by means of a method for installing a flange connection, wherein the flange connection has at least one first flange, a second flange, and a plurality of bolt systems, wherein the first flange and the second flange each have a plurality of flange recesses, wherein the flange recesses of the first flange can be aligned with the flange recesses of the second flange, and wherein each bolt system has at least one bolt, a nut, and a support, the method comprising the following steps: a. Determine the flange parameters of at least the first and second flanges of the flange connection. b. By analyzing and determining the typical elongation behavior of the bolt system, the typical stiffness C of the bolt system is determined. bolt And determine the axial stiffness of the flange body of the pre-tightened flange connection. c. Analytical and / or numerical analysis to specify the maximum permissible clearance size S n This ensures that, considering specific boundary conditions, the fatigue damage of the bolt system does not exceed the defined total damage. d. Considering the previously determined maximum permissible clearance size S n And the installation preload F that must be achieved during the preload period for fatigue safety of the connection. m The overall stiffness C to be achieved by the tensioned flange body is determined through analysis. target , e. Insert the bolt system into the aligned flange recesses of the first and second flanges. f. Install the bolt tensioning device onto the bolt. g. Apply installation preload F to the bolts. m And determine the overall stiffness C achieved by the tensioned flange. act , h. The overall stiffness C achieved act The overall stiffness C to be achieved target Compare them.

[0005] According to the invention, this objective is further achieved by using a bolt tensioning device comprising a housing, a tensioning unit, a distance measuring device, a tension determining device, and a calculation unit, wherein the achieved overall stiffness C can be measured by means of the distance measuring device. act The overall stiffness C to be achieved, determined numerically and / or analytically, can be stored using computational units. target , used to implement the above methods.

[0006] According to the invention, this objective is also achieved by means of a computer program product comprising a dataset including at least one sequence of reference values, the sequence of reference values ​​being determined according to the following steps: a. Determine the flange parameters of at least the first and second flanges of the flange connection. b. Determine the axial stiffness C of the bolt by analyzing and identifying the typical elongation behavior of the bolt system. bolt And determine the axial stiffness of the flange body of the pre-tightened flange connection. c. Analytical and / or numerical analysis to specify the maximum permissible clearance size S n This ensures that, considering specific boundary conditions, the fatigue damage of the bolt system does not exceed the defined total damage. d. Considering the previously determined maximum permissible clearance size S n And the installation preload F that must be achieved during the preload period for fatigue safety of the connection. m The overall stiffness C to be achieved by the tensioned flange body is determined through analysis. target , In each case, this reference value sequence reflects the overall stiffness C to be achieved, determined numerically and / or analytically. target With installation preload F m The target value of the relationship, where it is related to the installation preload F applied to the bolt system. m The overall stiffness C achieved is related to act It can be compared with the target value, thereby enabling the output of qualitative descriptions related to the flange connection at the location of the bolt system, with the aid of computer program products.

[0007] According to the present invention, this objective is also achieved by means of using a computer program product according to the above-described use or method.

[0008] According to the invention, this objective is also achieved by means of a storage medium comprising a dataset including at least one sequence of reference values, which in each case reflects the overall stiffness C to be achieved, determined numerically and / or analytically. target Target value and installation preload F m The relationship, wherein the reference value sequence is determined according to the following steps: a. Determine the flange parameters of at least the first and second flanges of the flange connection. b. Determine the axial stiffness C of the bolt by analyzing and identifying the typical elongation behavior of the bolt system. bolt And determine the axial stiffness of the flange body of the pre-tightened flange connection. c. Analytical and / or numerical analysis to specify the maximum permissible clearance size S n This ensures that, considering specific boundary conditions, the fatigue damage of the bolt system does not exceed the defined total damage. d. Considering the previously determined maximum permissible clearance size S n And the installation preload F that must be achieved during the preload period for fatigue safety of the connection. m The overall stiffness C to be achieved by the tensioned flange body is determined through analysis. target , And / or the aforementioned computer program products. Detailed Implementation

[0009] A method for installing a flange connection is proposed, wherein the flange connection has at least a first flange, a second flange, and a plurality of bolt systems, wherein the first flange and the second flange each have a plurality of flange recesses, wherein the flange recesses of the first flange can be aligned with the flange recesses of the second flange, and wherein each bolt system has at least one bolt, a nut, and a support. The method includes the following steps: a. Determine the flange parameters of at least the first and second flanges of the flange connection. b. By analyzing and determining the typical elongation behavior of the bolt system, the typical stiffness C of the bolt system is determined. bolt And determine the axial stiffness of the flange body of the pre-tightened flange connection. c. Analytical and / or numerical analysis to specify the maximum permissible clearance size S n This ensures that, considering specific boundary conditions, the fatigue damage of the bolt system does not exceed the defined total damage. d. Considering the previously determined maximum permissible clearance size S nAnd the installation preload F that must be achieved during the preload period for fatigue safety of the connection. m The overall stiffness C to be achieved by the tensioned flange body is determined through analysis. target , e. Insert the bolt system into the aligned flange recesses of the first and second flanges. f. Install the bolt tensioning device onto the bolt. g. Apply installation preload F to the bolts. m And determine the overall stiffness C achieved by the tensioned flange. act , h. The overall stiffness C achieved act The overall stiffness C to be achieved target Compare them.

[0010] Preferably, the proposed method is implemented in a specified order.

[0011] The proposed method is particularly useful for installing flange connections, especially in wind power equipment or similar structures. A flange connection consists of at least one first flange and a second flange. This arrangement provides a systematic and precise installation, increasing the reliability and stability of the connection.

[0012] Flange connections are crucial in modern wind power equipment, representing a key technology for producing renewable energy. These connections, consisting of at least one first flange and one second flange, are typically found in critical areas of the equipment, such as the connection between the tower and the hub, or between individual tower sections. The mechanical integrity of these connections is paramount, as they must withstand the dynamic and static loads generated during the operation of the wind power equipment. These loads vary depending on wind speed, wind direction, and other environmental factors.

[0013] Designing flange connections in wind power equipment presents challenges in accommodating these variable stresses. During equipment operation, the connections are exposed to constantly changing forces, leading to cyclic stress and potential signs of fatigue. Factors such as corrosion or temperature fluctuations can also negatively impact the integrity of the flange connections, especially in offshore applications. Therefore, proper flange installation, threaded connections, and sealing are essential to avoid leaks, premature wear, and even catastrophic failures.

[0014] Furthermore, the challenge lies in the fact that even when manufactured according to standardized designs, each flange connection is unique due to production variations. One aspect is the clearance between the flanges to be connected. These clearance dimensions can be affected by various factors, such as manufacturing tolerances, uneven load distribution, settlement processes, or thermal expansion.

[0015] Undesirable or uncontrolled clearance dimensions can lead to a host of problems. On one hand, excessive clearance can negatively impact the seal between flanges, potentially causing leaks and subsequently corrosion, especially in marine environments where wind turbines are frequently exposed to saline air. Suboptimal clearances can also negatively affect load transfer, thus impacting the overall stability of the connection. This is particularly important given the dynamic and cyclic loads that wind turbines are exposed to.

[0016] In addition to mechanical integrity issues, excessive clearance dimensions can also lead to vibration problems. Vibrations can propagate along the tower and negatively impact the equipment's lifespan and efficiency.

[0017] Furthermore, it is worth noting that uncontrolled clearances also represent a potential hazard to bolted systems. Clearances can lead to uneven bolt load distribution, thereby increasing the risk of fatigue fracture.

[0018] For all these reasons, it is crucial to precisely define, monitor, and optionally adjust the clearance dimensions between flanges during the construction and operation of wind power equipment.

[0019] An effective and secure connection between at least two flanges is crucial in wind power generation equipment. The design and implementation of such a connection requires an understanding of the fundamental mechanical principles, specific requirements, and challenges arising in the context of wind power generation equipment.

[0020] The first and second flanges each have flange recesses that can be aligned with each other. A bolt system is introduced into these aligned recesses. In each case, the bolt system preferably includes at least one bolt, nut, and support, the bolt preferably being a threaded bolt. The support can be designed, for example, as a screw head or a countersunk nut. The bolt system may also have at least one washer, which may preferably be arranged below the nut and / or support. In one design, the nut and / or countersunk nut is specified to have an internal thread that corresponds to the external thread of the preloaded bolt. More preferably, the support surface of the nut is designed to eliminate the need for a washer. The nut preferably has a flat support surface, more preferably shaped to be perpendicular to the thread axis of the nut. If the support is designed as a countersunk nut, the above description of the nut also applies to the countersunk nut of the support. The bolt is preferably a threaded bolt whose external thread corresponds to the internal thread of the nut and, optionally, the internal thread of the countersunk nut, or whose external thread geometry corresponds to the internal thread of the nut and, optionally, the internal thread of the countersunk nut, preferably when maximum force is applied to the bolt. In one design, the threaded connection or bolt system is the HV screw set.

[0021] An example of a bolt system is a threaded bolt that includes two nuts. Another example is a threaded bolt that includes two nuts and two washers. Yet another example is a threaded screw that includes a nut. Still another example is a threaded screw that includes one nut and two washers. However, because a threaded screw does not have a bolt, it is neither part of a bolt system nor the bolt system itself. Unlike a threaded screw, a bolt has no head.

[0022] Bolt tensioning devices can be designed as, for example, torque wrenches, electric torque screwdrivers, hydraulic torque screwdrivers, pneumatic torque screwdrivers, or especially hydraulic bolt tensioning devices. The bolt tensioning device can preferably induce preload in the bolt system or the bolt itself using a hydraulic method. In one design, the bolt tensioning device is operated by an installer or a robot. The bolt system is preferably hydraulically tensioned. Using a hydraulic system makes precise and repeatable tensioning of the bolt system possible. This method enables bolt tensioning with a level of precision and force unattainable by traditional manual methods.

[0023] In step a of the method, flange parameters of at least the first and second flanges of the flange connection are determined. The flange parameters recorded and analyzed include numerous physical and material-related characteristics specific to their respective applications. For example, flange parameters may include flange thickness, flange outer diameter, flange inner diameter, the structure connecting the flange to the tower wall, the distance between flange recesses, the diameter of the flange recesses, and the type and / or material of the bolt system used.

[0024] For the purposes of this invention, the exemplary enumerations should not be considered exhaustive, but rather can be supplemented as part of ordinary expertise.

[0025] In step b of the method, the typical elongation behavior of the bolt system and the axial stiffness C of the bolt are determined through analysis. bolt And determine the axial stiffness of the flange body of the pre-tightened flange connection. Preferably, the compression behavior of the bolt tensioning device is also determined. This is done using the typical elongation behavior of the bolt system and the axial stiffness C of the bolt. bolt Knowledge of the axial stiffness of the flange body of the pre-tightened flange connection, and more preferably knowledge of the compression behavior of the bolt tensioning device, allows for advantageous further calculations.

[0026] The elongation behavior of a bolt system describes how the bolt system, especially the bolt itself, elongates or shortens under load. This is based on the inherent material properties of the bolt and can be determined using classical mechanical tests and analyses, such as tensile tests. Elongation behavior provides information about how the bolt responds to different loads, particularly regarding elastic and plastic deformation. If the material properties are known, the elongation behavior can be determined mathematically.

[0027] The axial stiffness of a bolt is a measure of its resistance to axial forces. Axial stiffness is affected by bolt geometry, material, and application. Specifically, stiffness can be calculated according to VDI 2230 of December 2014.

[0028] The axial stiffness of the flange body of the pre-tightened flange connection is preferably determined based on the process variables measured during bolt pre-tightening.

[0029] For example, in the tensioning of a bolt system or bolts, pre-tightening can, in sequence and more preferably, have the following order: - Apply tension individually until the restoring force is reached or until the restoring pressure, for example, from about 30 bar to about 100 bar, is reached. - Apply tension to the bolts of the bolt system until a specific maximum force is reached, and preferably determine, more preferably continuously determine during the application of tension, the distance associated with bolt elongation, compression of the bolt tensioning device, and / or flange compression of the flange connection.

[0030] - Preferably, the nuts of the bolt system are retightened using a specific torque. - Release the tension to approximately 0 N. - Apply a tensile force corresponding to the installation preload.

[0031] - In one design, it is specified that the aforementioned steps be repeated before applying the installation preload.

[0032] When the term "about" is used in conjunction with numerical values ​​or ranges as part of this invention, it should be understood as a tolerance range conventionally considered by those skilled in the art, particularly providing a tolerance range of +20%, preferably +10%, and more preferably +5%. If different numerical ranges are specified in this invention, such as preferred and more preferred numerical ranges, the lower and upper limits of the different numerical ranges can be combined with each other.

[0033] The description of this method is preferably performed before, during, and / or after each step. The steps for pre-installing the bolt system mentioned are not limiting. In further designs, further sequences of operations are also possible, nested several times, wherein all steps are preferably described. In one design, the tensioning parameters of the threaded connection are specified by means of a calculation unit. Parameters may include, for example, screw identification number, maximum force, elongation value, bolt tensioner compression, flange compression, achieved installation preload, distance and / or angle measurements taken to tension the threaded connection, installer's name, company description, flange description, diameter of the threaded connection, tension applied by the bolt tensioner, hydraulic pressure, loosening force, and in particular, batch numbers of all tools used, batch numbers or identifiers of the threaded connection or bolt system, or individual components thereof, software version of the calculation unit, date, time, and description of the operation performed, qualitative description of successful bolt system tensioning, ambient temperature, and / or rotation angle of the nut of the threaded connection. The description of threaded connection tensioning may preferably be performed before, during, and / or after tensioning the threaded connection or bolt system separately by means of a bolt tensioner.

[0034] For the purposes of this invention, a "flange body" is understood as an integral or assembled component by means of which two or more components can be mechanically connected to each other. A flange body particularly includes at least a first flange and a second flange. The flange body is typically circular or annular and has recesses or openings for receiving fastening elements such as bolted systems. It can be composed of various materials, including but not limited to metals, alloys, plastics, or composite materials. In particular, the flange body serves not only for physical connection purposes but, in one embodiment, also ensures a tight seal between the connected components to prevent the ingress of liquids, gases, or other unwanted components. In one embodiment, the flange body can also help to distribute the load or tension acting on the connection evenly, thereby increasing the durability and reliability of the overall structure.

[0035] In this invention, the installation preload F is... m This should be understood as the force on the bolt, which is less than or equal to the installation tension F required for final installation. target Therefore, the installation preload F used to preload the bolt system m The tension is applied by a bolt tensioning device, and is particularly used to determine the overall stiffness C achieved. act Installation tension F target It is the force applied by the bolt tensioning device when the nut in a bolt system is threaded. Therefore, the installation tension F target This is the force that will ultimately be used to tension the bolt system. In one embodiment, the installation tension force F target Approximately equal to the installation preload F m In another embodiment, the installation preload F is applied.m Is the installation tension F target The ratio is approximately 0.1 to approximately 0.95 times, preferably approximately 0.5 to approximately 0.95 times, and more preferably approximately 0.7 to approximately 0.95 times. For the purposes of this invention, "pre-tightening" of a bolt system or flange connection refers to applying a pre-tightening force to the bolts of the bolt or flange connection.

[0036] Step c of the proposed method provides a method for specifying the maximum permissible gap size S. n Analysis and / or numerical analysis are performed to ensure that, considering specific boundary conditions, the fatigue damage of the bolt system does not exceed the defined total damage.

[0037] For the purposes of this invention, "fatigue damage" is understood as a progressive material failure process caused by repeated load cycles or tension fluctuations, typically significantly below the material's maximum strength. These repeated stresses lead to microcracks in the material, which can propagate over time until the structural integrity of the component is negatively impacted and it ultimately fails. Regarding flange connections, particularly in wind power equipment, fatigue damage specifically refers to the gradual weakening of the bolted system and other components connected to it, influenced by the constant and dynamic loads exposed to the equipment during its operation.

[0038] For the purposes of this invention, "total damage" is understood as the cumulative damage to a material or structure over its entire service life or a specific period, particularly the cumulative damage to flange connections or bolted systems. This includes initial microscopic defects and the resulting macroscopic damage, which may be caused by repeated load cycles. In the context of this invention, total damage specifically relates to bolted systems and corresponding components in flange connections of, for example, wind power generation equipment. Compared to "fatigue damage," which specifically describes the gradual failure process caused by repeated load cycles, total damage encompasses all types of damage, including but not limited to fatigue, corrosion, mechanical damage, and other environmental effects. The objective is to minimize total damage by means of the proposed method, with particular focus on preventing fatigue damage, as fatigue damage is typically one of the most critical and unpredictable types of damage in such structures.

[0039] Because the size of these clearance dimensions is directly related to the durability and safety of the bolt system, numerical and / or analytical analysis is advantageous. When the clearance dimensions exceed the allowable limits, they can lead to premature fatigue damage to the bolt system under the enormous loads exposed to wind power equipment, especially under turbulent wind conditions.

[0040] Numerical and / or analytical analysis is used to ensure that the clearance dimensions are within tolerances, which does not compromise the structural integrity of the bolted system. This considers not only the physical dimensions of the bolted system and flange connection but also specific boundary conditions that may exist, such as those caused by their respective materials, environment and operating climate, or by special application requirements. By precisely defining the maximum permissible clearance dimension, a defined total damage limit is established, which must not be exceeded to ensure optimal function and service life of the entire flange connection.

[0041] Another advantage of this numerical and / or analytical analysis in step c is that it not only evaluates the immediate behavior of the bolted system under different load conditions, but also helps define preventative measures to detect and eliminate potential weaknesses before they become critical issues. The result is a robust, safe, and efficient flange connection specifically developed for the requirements and challenges of wind power generation equipment.

[0042] Numerical analysis preferably includes at least one simulation. The numerical analysis is preferably performed using the finite element method (FEM). In particular, simulations are performed over time for multiple gap dimensions under specified load conditions. The analysis is understood as calculations using, in particular, known, measured, or numerically determined values, preferably using at least one mathematical formula.

[0043] For the purposes of this invention, "boundary conditions" refer to specific external factors or circumstances that must be considered during the evaluation and design of flange connections, for example, for wind power generation equipment. These are, in particular, load conditions, flange parameters, and / or preload.

[0044] "Load condition" refers to the specific force effects acting on flange connections during the operation of wind power equipment. For example, in the environment of wind power equipment, wind loads play a crucial role because they exert continuous and varying pressures on the equipment structure. These wind loads are not constant and can vary drastically depending on weather conditions, geographical location, and season. They act on the flange connection within a defined time period and can be stable or sudden. The effects of these stresses must be considered when designing, installing, and monitoring flange connections to ensure the safe connection of wind power equipment flanges.

[0045] In one design, specific boundary conditions, especially load states, are specified, at least in part, derived from the Markov matrix P representing the load states and local damage for flange connections. Based on this Markov matrix P, the total damage value D for each bolt system is derived. MAR The total damage value D MAR Less than 1.

[0046] The complexity of load states and local damage can be revealed using a Markov matrix p. This matrix provides a systematic and mathematical observation of variable load states and their impact on the integrity of flange connections.

[0047] A Markov matrix is ​​a tool in probability theory used to describe the probability of transitions between different states in a system over time. This matrix is ​​particularly useful when the probability of a state change is a function of the current state rather than the previous states; this concept is called the Markov property.

[0048] In the context of flange connections, the states of the Markov matrices are defined such that they represent different load states and localized damage. Each element of the matrix specifies the probability that the flange connection will transition from a specific state, such as a particular load state, to a different state, such as a particular localized damage. Specifically, only load states are collected from the Markov matrices, not transition probabilities associated with bolted connection failure. The Markov matrices are preferably provided by the flange manufacturer or the wind turbine manufacturer. In one embodiment, the load states are measured at either the existing flange connection or the wind turbine, respectively.

[0049] The total damage value D extracted from the Markov matrix P MAR A quantitative estimate of the damage caused by the bolt system is provided. D less than 1 MAR The value indicates that the system is not completely damaged; despite the changing load conditions and localized damage, the flange connection remains functional.

[0050] By applying this method, accurate and adaptive assessments of flange connections can be performed, taking into account varying load conditions and their potential impact on the connection's service life and stability. Therefore, potential weaknesses can be identified during flange connection installation, and proactive measures can be taken to ensure the durability and safety of wind power equipment. In particular, load conditions derived from Markov matrices can be used for FEM analysis to simulate flange connections with different clearance dimensions, installation preload, and / or installation forces.

[0051] Numerical analysis, for example, involves multiple defined load states and multiple different installation preloads F that can be applied to a bolt system. m In this case, several, preferably multiple, simulations are performed on the flange connection, particularly an FEM analysis, which has defined parameters for the flange connection, wherein during each individual simulation, in each simulated case, the maximum clearance dimension S between the flanges is included. n At least one defined gap.

[0052] Numerical analysis, particularly the execution of multiple simulations specifically tailored to the parameters of the flange connection, models the behavior of the flange connection under defined load conditions. Preferably, different installation preloads F applied to the bolt system are considered. m During the numerical analysis, it is preferable to consider or numerically analyze multiple different gaps between flanges separately. Preferably, the maximum gap size S is determined using numerical analysis. n The defined clearance. It is necessary to observe this maximum clearance dimension because it represents the most demanding conditions that the flange connection must endure during operation.

[0053] Numerical analysis can be used to advantageously determine the relationship between the clearance dimension and the installation preload and / or installation force, indicating whether the flange connection has sufficient force to lock the connection (non-positive connection) or insufficient force to lock the connection. Maximum clearance dimension S n It is the maximum simulated gap size that has sufficient force to lock the connection under the condition of installation preload and / or installation force.

[0054] In the exemplary design of step c, specific boundary conditions are first determined, such as material properties, environmental conditions, and specific application requirements. Then, different load states acting on the flange connection during operation are determined, such as static and dynamic loads, wind loads in the case of wind power generation equipment, and variable load cycles.

[0055] For example, a Markov matrix is ​​then constructed. The states that will be displayed in the Markov matrix P are defined to represent different load states and local damage to the flange connection. For example, data relating to the transition probabilities between the defined states are collected from experimental measurements or literature. For instance, in wind power equipment, load states are measured at existing flange connections. This data is used to construct a matrix P that includes the transition probabilities between different load states and local damage.

[0056] Furthermore, a first calculation is performed in an exemplary manner to estimate the gap size based on data from a Markov matrix. For example, the total damage value D is calculated here. MAR This refers to the damage accumulation rate, which is preferably less than 1 to indicate that the system is not completely damaged.

[0057] For example, in numerical analysis, a numerical model of the flange connection is first created. Parameters for the simulation are specified, including different gap sizes, load states, and installation preload. The load states from the Markov matrix are integrated into the simulation. Preferably, transition probabilities from the Markov matrix are not included in the simulation. The Markov matrix is ​​primarily used to utilize stress and load sequences in the simulation. Multiple FEM simulations are performed to model the behavior of the flange connection under different conditions. Simulations are performed for different gap sizes, and the resulting tension and deformation are analyzed under the load states defined by the Markov matrix.

[0058] Preferably, the results of the FEM simulation are evaluated to analyze the tension force distribution and / or identify critical ranges. The results are compared with the allowable limits of fatigue damage and total damage. The maximum clearance size S that still guarantees the structural integrity of the flange connection is identified. n .

[0059] For example, high-strength steel is used in the bolt system and flanges of wind turbine equipment, exposed to various stresses, such as marine climates and high wind loads. The minimum service life is, for example, 20 years. States such as different wind speeds, operating cycles, and shutdown phases are defined. Transfer probabilities are collected and displayed in the Markov matrix p. Preliminary calculations for estimating the gap size show, for example, 0.2 mm. A 3D model of the flange connection is created, and the simulation is specified. During the simulation, load states, different gap sizes, and preload are considered according to the Markov matrix, with transfer probabilities particularly neglected. FEM analysis is performed to analyze the tension distribution and deformation. The maximum gap size S is determined. n For example, 0.25 mm, in this case, the tension is still within the allowable limit. Verify the results, adjust the model if necessary, and record the changes.

[0060] In step c, preferably only numerical analysis is performed, more preferably only FEM simulation is performed, to specify the maximum allowable gap size.

[0061] In step d of the proposed method, it is specified that the previously determined maximum permissible clearance size S is taken into account. n And the installation preload F that must be achieved during the preload period for fatigue safety of the connection. m The overall stiffness C to be achieved by the tensioned flange body is determined through analysis. target .

[0062] The determined or desired overall stiffness C typically refers to the flange connection's ability to resist deformation. Higher stiffness means the connection can resist external forces acting upon it. Overall stiffness is particularly a measure of the force-locking connection between the first and second flanges. For example, the overall stiffness is greater if there is no gap between the flanges than when there is a gap. For the purposes of this invention, the determined or desired overall stiffness of the flange connection is related to the installation preload F. pre The relationship is usually understood as division C / F pre The value of .

[0063] For the purposes of this invention, "fatigue safety" is understood to mean that components, particularly bolted systems and flange connections thereto, can withstand repeated load cycles and tension fluctuations throughout their entire specified service life without showing signs of gradual material failure. Therefore, fatigue safety ensures that undesirable microcracks or material weakening do not occur despite repeated and variable loads, such as those encountered in wind power equipment. A specific objective is to ensure the structural integrity of flange connections and / or bolted connections for a specified period, thereby preventing premature failure or damage due to signs of fatigue.

[0064] Especially based on the maximum gap size S n Determine the maximum clearance size S max In this case, for each bolt system, the simulation will not exceed the defined total damage. The maximum clearance size S max Preferably, the maximum clearance size is defined from a set of measured or simulated clearance sizes. This size represents the maximum distance between the two flanges in the connection, which is particularly considered to be barely fatigue-resistant. During the analysis and simulation of the flange connection, the maximum clearance size S is determined. max In this case, whether the total damage does not exceed the definition of each bolt system.

[0065] Setting this damage limit and determining the corresponding maximum clearance size ensures that the flange connection remains functional throughout its service life and has sufficient safety margin relative to potential fatigue damage. In step e, the bolt system is introduced into the mutually aligned flange recesses of the first and second flanges, and in step f, the bolt tensioning device is installed on the bolts.

[0066] In step g, the installation preload F is applied. m Apply to the bolts and determine the overall stiffness C achieved by the tensioned flange. actFor this purpose, especially during flange tensioning, the length change is determined by means of distance measurement, which can be determined at least based on the bolt elongation and the compression of the flange connection and the bolt tensioning device. Since the force applied by the bolt tensioning device is known, the compression of the flange connection can be determined based on the bolt elongation behavior determined prior to the process and the known compression behavior of the bolt tensioning device. The achieved overall stiffness C act The calculation is as follows: C act =(Δl / F) m )- C bolt Δl here refers to the preload force F applied by the bolt tensioning device during mold installation. m The length change measured over time, preferably after the compression of the bolt tensioning device has been removed. Furthermore, C bolt This refers to bolt stiffness, which is preferably calculated based on VDI2230 from December 2014.

[0067] For example, according to the overall reference EP 3566816A1, a method for threaded connection bolts is known, in which a tensioning force is applied to the bolt until a specific maximum force is reached, and an elongation value is determined, which is related to bolt elongation, bolt tensioner compression, and flange compression in flange connections. The method of EP 3566816A1 can be used in conjunction with the proposed method.

[0068] In step h of the method, the achieved overall stiffness C act The overall stiffness C to be achieved target A comparison is made. This comparison provides a qualitative assessment of the fatigue safety of the flange connection, particularly at the location where the bolts have just been tightened. When the overall stiffness C is reached... act Less than the desired overall stiffness C target When this is the case, it can be preferably stated that the flange connection does not have sufficient fatigue safety. When the overall stiffness C achieved... act Greater than or equal to the overall stiffness C to be achieved target In this case, it can be preferably stated that the flange connection has sufficient fatigue safety.

[0069] Preferably, the comparison result of step h is specified as the output. More preferably, the comparison result of step h is transmitted to the bolt tensioning device. More preferably, the bolt tensioning device is controlled based on the comparison result of step h. More preferably, based on the comparison result of step h, the bolt system is pre-tightened again or loosened using the installation preload, preferably automatically, by means of the bolt tensioning device. More preferably, based on the comparison result of step h, the bolt system is pre-tightened again or loosened using the installation preload, preferably automatically, by means of the bolt tensioning device, or the bolt tensioning device is released from the bolt system.

[0070] One design specifies that, when the applied installation preload F... m The overall stiffness C achieved is related to act The value is greater than or equal to the applied installation preload F. m The relevant overall stiffness C to be achieved target In step i, tighten the nuts of the bolt system. When the applied installation preload F... m The overall stiffness C achieved is related to act Greater than or equal to the applied installation preload F m The relevant overall stiffness C to be achieved target At this time, it is preferable to fully tighten the bolt system. In one embodiment, then, before fully tightening the bolt system, i.e., before tightening to the installation tension F... target Previously, the bolt system was partially or completely loosened again.

[0071] One design specifies that, when the applied installation preload F... m The overall stiffness C achieved is related to act The value is less than the applied installation preload F. m The relevant overall stiffness C to be achieved target When the target value is reached, after step h, the installation preload F is applied again. m Pre-tighten the bolt system. Specifically, this means: when the determined pre-tightening force F is applied... m The overall stiffness C achieved is related to act The applied installation preload F was not achieved. m The relevant overall stiffness C to be achieved target When the specified target value is reached, the bolt system is pre-tightened or tensioned again to the installation tension F. target By means of installation preload F m This pre-tightening aims to achieve the required overall stiffness, which is necessary for a safe and stable connection, and can optionally be achieved by means of the plastic deformation of the flange connection and / or bolt system.

[0072] Applying installation tension F target Previously, it was preferable to first at least partially loosen the bolt system. This could be done partially or completely. During this process, the overall stiffness C achieved was continuously measured. act When the overall stiffness C is reached act Ultimately reaching or exceeding the installation preload F m The relevant measures are used to achieve the overall stiffness C. target At this time, the flange connection is classified as fatigue-resistant. When the required fatigue safety is not immediately achieved, the process is preferably performed approximately once to approximately three times.

[0073] In one embodiment, it is specified that when the overall stiffness C is reached... act Not greater than or equal to the applied installation preload F m The relevant overall stiffness C to be achieved target Then, loosen the bolt system partially or completely again, and then tighten it to the installation tension F. target The overall stiffness C achieved by measurement act If the applied installation preload F m Related to, and then the overall stiffness C achieved act Greater than or equal to the applied installation preload F m The relevant overall stiffness C to be achieved target Therefore, the flange connection is preferably evaluated as having sufficient fatigue resistance.

[0074] One design specifies that, when the applied installation preload F... m The overall stiffness C achieved is related to act The value is less than the applied installation preload F. m The overall stiffness C to be achieved, determined numerically and / or analytically. target When the target value is reached, after step h, the bolt system is loosened. In one design, after loosening the bolt system, at least one slab is inserted between the first and second flanges in the area of ​​the bolt system. Steps g and h can then be subsequently performed again, during which the bolt system is tensioned in a controlled manner. If this measure is successful, the nuts of the bolt system are preferably tightened, particularly in a defined manner.

[0075] When the overall stiffness C is reached act The applied installation preload F was not achieved. m The relevant overall stiffness C to be achieved and determined numerically and / or analytically. targetThis can lead to unwanted vibrations, loosening, or even connection failure. In such cases, one embodiment of the method provides a bolt loosening system. This is primarily used for the purpose of modifying or adjusting the connection. In this context, the so-called "shimming" comes into play, representing a method known in the art for adjusting flange connections. Specifically, special sheets or washers are used, inserted between the flanges to correct the distance, thereby ensuring a firm and stable fit or force-locked connection when the flanges are stacked on top of each other.

[0076] In another design, these sheets can be specifically designed for flange connections. These can be sheets with U-shaped recesses that surround the bolts, ensuring particularly precise assembly and providing quick insertion without having to fully loosen the bolts. Therefore, these sheets, or "gaskets," are selectively inserted into the bolt area to preferably optimize the force-locking connection.

[0077] In one design, steps g and h are specified to be repeated. Preferably, steps g and h are repeated after at least one sheet has been introduced between the flanges. Specifically, the installation preload F is... m Apply the tension to the bolts sequentially and determine the overall stiffness C achieved by the tensioned flange. act Then, it is compared with the overall stiffness C to be achieved. target A comparison was made. In one design, the installation preload F was used. m The installation preload F m Unlike previous installation preloads, and especially larger or smaller.

[0078] One design specifies that, before performing steps h to i on the first bolt system, all bolt systems of the flange connection are tightened to the specified installation preload F. target A portion of them. They are especially characterized by approximately 0.01*F. target To approximately 0.95* F target The preferred value is approximately 0.01*F target To approximately 0.3* F target The tension force is used to tighten it.

[0079] One design specifies that steps g to h are performed on the bolt system in each case where the gap between the first and second flanges is the largest. The bolt tensioning sequence is specifically specified here. An exemplary embodiment can be described as follows: During the installation of wind turbine equipment, particularly during the connection of large flanges that connect, for example, tower sections to each other, different gap sizes often occur between the flanges to be connected. For example, it is specified that the bolt located at the point with the largest gap size between the first and second flanges is first identified. This particular bolt serves as a reference point for the following installation steps. Steps g to h are specifically performed on this bolt system to ensure optimal flange tension and alignment. Choosing this particular bolt system as a starting point ensures that the tension and torque applied to the flanges are applied sequentially, providing uniform and secure tightening for all bolts. By starting from the point with the largest gap size and continuing systematically in the specified order, uniform load distribution and a secure assembly throughout the flange connection can be ensured. In practice, this may mean that during the flange installation of wind turbine equipment, the installer or robot first identifies the area with the largest gap size. The first bolt is tightened there, where steps g to h are performed. The remaining bolts are then tightened in the specified order, or the bolt systems with the largest gap size are identified sequentially, thereby ensuring the alignment of the flange or the optimal closure of the gap, respectively.

[0080] In an exemplary embodiment, a flange connection is installed and preparation steps are performed, wherein relevant parameters and stiffness are calculated. After the bolt tensioning device is installed, a preload is applied to the bolts, and the overall stiffness is measured. It is determined that the overall stiffness is less than a pre-calculated value. The bolt system is loosened, but the nuts are not tightened. A sheet is placed between the flanges, and the preload and measurement steps are repeated. The required stiffness is then achieved, and the nuts of the bolt system are tightened to the specified installation tension.

[0081] In another exemplary design, a bolt tensioning device is installed. A preload is then applied to the bolts using the bolt tensioning device, and the overall stiffness related to the preload of the flange connection is detected using a sensor. For example, the overall stiffness is lower than a target value. Therefore, to reach the target value, a method for retightening the bolt system is initiated. This process is repeated, and the overall stiffness is checked again. For example, despite retightening the bolt system, the overall stiffness is still lower than the target value. In response, the bolt system is loosened. A shim is placed between the two flanges in the bolt system area. After inserting the shim, the steps of applying preload and comparing stiffness are repeated. With the aid of this additional shim, the desired stiffness is finally achieved, and installation continues, wherein the nuts of the bolt system are tightened to the specified installation tension. If the target value is still not reached, the above steps can optionally be repeated using a thicker shim or multiple shims.

[0082] Furthermore, a method for using a bolt tensioning device is proposed, which includes a housing, a tensioning unit, a distance measuring device, a tension determining device, and a calculation unit, wherein the overall stiffness C achieved can be measured by means of the distance measuring device. act The overall stiffness C to be achieved, determined numerically and / or analytically, can be stored using computational units. target , used to implement the above methods.

[0083] The bolt tensioning device has a housing containing a tensioning unit for applying the necessary preload to the bolts and a precise distance measuring device. The overall stiffness C achieved by the flange. act The distance can be determined during the tensioning process using a distance measuring device. The integrated computing unit, as part of the bolt tensioning device, preferably allows storage of the overall stiffness C to be achieved, determined through analysis. target This value is preferably used as a reference value, against which the actual stiffness achieved during installation is compared. The calculation unit can be installed in the housing, or it can be connected wired or wirelessly to remaining components spaced apart from the housing, particularly distance measuring devices. Preferably, the calculation unit is capable of storing a series of reference values. The advantage of this is that different target values ​​for the overall stiffness can be stored depending on the flange type, material, or application. Another aspect that can be achieved by means of the calculation unit is that the achieved overall stiffness C can be calculated based on the measured values. act And / or flange compression Δf.

[0084] A computer program product is also proposed, comprising a dataset including at least one sequence of reference values, which is determined according to the following steps: a. Determine the flange parameters of at least the first and second flanges of the flange connection. b. Determine the axial stiffness C of the bolt by analyzing and identifying the typical elongation behavior of the bolt system. bolt And determine the axial stiffness of the flange body of the pre-tightened flange connection. c. Analytical and / or numerical analysis to specify the maximum permissible clearance size S n This ensures that, considering specific boundary conditions, the fatigue damage of the bolt system does not exceed the defined total damage. d. Considering the previously determined maximum permissible clearance size S n And the installation preload F that must be achieved during the preload period for fatigue safety of the connection. m The overall stiffness C to be achieved by the tensioned flange body is determined through analysis. target , In each case, this reference value sequence reflects the overall stiffness C to be achieved, determined numerically and / or analytically. target With installation preload F m The target value of the relationship, where it is related to the installation preload F applied to the bolt system. m The overall stiffness C achieved is related to act The comparison can be made with target values, thereby enabling the computer program product to output a qualitative description of the flange connection at the location of the bolt system. The computer program product preferably performs the above method. The proposed computer program product advantageously enables the evaluation of the integrity and suitability of the flange connection based on reference values. Furthermore, the evaluation results can be advantageously used during the installation of the flange connection.

[0085] The computer program product includes at least one dataset comprising at least one sequence of reference values. In each case, this set represents a target value, which represents the overall stiffness C to be achieved, determined numerically and / or analytically. target With installation preload F m The relationship between the computer program product and the actual applied installation preload F is discussed. In practical applications, this computer program product provides information related to the actual applied installation preload F. m The measured and achieved overall stiffness C of the relevant, given bolt system. act A direct comparison with the corresponding target value. Based on this comparison, the procedure can generate a qualitative description related to the integrity and quality of the flange connection at a specific location in the bolted system.

[0086] One design specifies that, based on qualitative specifications, the computer program product prompts the user to tighten or loosen the nuts of a bolt system. The computer program product preferably provides the possibility of initiating automated actions based on the qualitative specifications made. This means that if the computer program product identifies a discrepancy or potential problem, it can prompt, for example, to tighten or loosen the nuts of the bolt system. In cases where a flange connection is assessed as unsuitable or potentially unsafe, the program can also instruct the user to loosen the entire bolt system to introduce, for example, at least one slab between the flanges.

[0087] Furthermore, the evaluation results are advantageously transmitted to the robot via a computer program, and the robot installs the flange based on the results. For example, if fatigue safety cannot be guaranteed, the robot loosens the currently tensioned bolt system to allow for the insertion of the sheet. Conversely, if fatigue safety is guaranteed, the robot tightens the bolt system to the installation tension F. target .

[0088] In one design, an output unit is provided that instructs the installer what needs to be done on the current bolt system: for example, loosening or tightening the bolt system.

[0089] The use of the aforementioned computer program product in the above method is also proposed.

[0090] A storage medium comprising a dataset including at least one sequence of reference values, each sequence reflecting the overall stiffness C to be achieved through numerical and / or analytical methods, is also proposed. target With installation preload F m The target value of the relationship, wherein the reference value sequence is determined according to the following steps: a. Determine the flange parameters of at least the first and second flanges of the flange connection. b. Determine the axial stiffness (C) of the bolt by analyzing and identifying the typical elongation behavior of the bolt system. bolt ), and determine the axial stiffness of the flange body of the pre-tightened flange connection, c. Analysis and / or numerical analysis to specify the maximum permissible clearance size (S n This ensures that, considering specific boundary conditions, the fatigue damage of the bolt system does not exceed the defined total damage. d. Taking into account the previously determined maximum permissible clearance size (S) n ) and the installation preload force (F) that must be achieved during preload to ensure fatigue safety of the connection. m The overall stiffness (C) to be achieved by the tensioned flange body is determined through analysis. target ), And / or the aforementioned computer program products.

[0091] Storage media comprising datasets with at least one sequence of reference values ​​advantageously demonstrate the technical effects related to the optimization and efficiency of flange connections. The storage media provides the possibility of efficiently storing and retrieving key data representing the overall stiffness C to be achieved, determined numerically and / or analytically. target Target value and installation preload F m The relationship. This data is the result of technical calculations, and its rapid availability is crucial for the safe and efficient construction and operation of mechanical systems, such as bolt tensioning devices or robots incorporating such devices.

[0092] The technological advantage of the storage medium and the datasets thereon lies particularly in its ability to accelerate the automated decision-making, adjustment, and implementation of flange connections. By maintaining these available, specific data relationships, engineers and experts can quickly determine and apply the optimal value of the installation preload related to the desired overall stiffness. This reduces the need for repetitive manual calculations, minimizes errors, and improves the reliability of the entire system.

[0093] The combination of storage media and corresponding computer program products also automates certain processes that would otherwise require manual and time-consuming execution. This results in another technological effect: improved efficiency and accuracy in implementing flange connections.

[0094] The current dataset has significant technical characteristics, including a series of reference values ​​that, in each case, represent the overall stiffness C to be achieved, determined numerically and / or analytically. target Target value and installation preload F m In this context, the dataset is not merely considered a collection of information or pure data; rather, it is seen as an important tool that helps solve specific technical problems.

[0095] This dataset was created based on extensive technical considerations and calculations. Its purpose is to better understand and control the interactions and collaboration between different technical components, particularly the overall stiffness of the system and the installation preload required for this purpose. Utilizing the relational knowledge included in the dataset, installation preload can be applied precisely, optimally, and repeatably to achieve the desired overall stiffness. This has a direct impact on the system's mechanical properties and can improve the overall system's performance, safety, and service life.

[0096] When the dataset is stored on an appropriate storage medium and interpreted by the corresponding computer program product, it also enables the automation of processes required for installing, adjusting, and optimizing flange connections. This not only provides faster and more accurate implementation but also prevents human error and reduces the need for manual intervention, which in turn leads to an increase in overall productivity and efficiency.

[0097] In summary, the storage media and datasets not only serve as passive data storage but also support the technical optimization and efficiency improvement of flange connection systems. This achieves significant and substantial technical benefits.

[0098] The method described for installing flange connections leverages comprehensive and / or numerical analysis of relevant flange and bolt parameters to advantageously ensure accurate, optimized, and repeatable installation. By determining permissible overall stiffness and other key parameters through analysis and / or numerical methods, the integrity and service life of the flange connection can be significantly improved. Furthermore, considering specific boundary conditions during installation and systematically determining the maximum permissible clearance dimension, high fatigue safety of the bolt system and flange connection is advantageously guaranteed. With the implementation of this method, the use of computer program products benefits from process automation and standardization, thereby minimizing human error and improving overall efficiency. Storage media including reference value sequence data are advantageously used as tools, providing consistent and accurate application of the method, ultimately improving the quality and reliability of tensioned flange connections.

Claims

1. A method for installing a flange connection, wherein the flange connection has at least one first flange, a second flange, and a plurality of bolt systems, wherein the first flange and the second flange each have a plurality of flange recesses, wherein the flange recesses of the first flange are alignable with the flange recesses of the second flange, and wherein each bolt system has at least one bolt, a nut, and a support, the method comprising the following steps: a. Determine the flange parameters of at least the first flange and the second flange of the flange connection. b. By analyzing and determining the typical elongation behavior of the bolt system, the axial stiffness (C) of the bolt is determined. bolt ), and determine the axial stiffness of the flange body of the pre-tightened flange connection, c. Analysis and / or numerical analysis to specify the maximum permissible clearance size (S n This ensures that, considering specific boundary conditions, the fatigue damage of the bolt system does not exceed the defined total damage. d. Taking into account the previously determined maximum permissible clearance size (S) n ) and the installation preload force (F) that must be achieved during preload to ensure fatigue safety of the connection. m The overall stiffness (C) to be achieved by the tensioned flange body is determined through analysis. target ), e. Insert the bolt system into the flange recesses of the first and second flanges, which are aligned with each other. f. Install the bolt tensioning device onto the bolt. g. Apply an installation preload (F) to the bolt. m ), and determine the overall stiffness (C) achieved by the tensioned flange. act ), h. The overall stiffness achieved (C) act ) and the overall stiffness to be achieved (C) target (Compare) 2. The method according to claim 1, characterized in that, When the applied installation preload (F) m The overall stiffness (C) achieved is related to act The value of ) is greater than or equal to the applied installation preload (F). m The overall stiffness (C) to be achieved is related to... target In step i, the installation tension force (F) is used. target Tighten the nuts of the bolt system.

3. The method according to one or more of the preceding claims, characterized in that, When the applied installation preload (F) m The overall stiffness (C) achieved is related to act The value of ) is less than that of the applied installation preload (F). m The overall stiffness (C) to be achieved is related to... target When the target value is reached, after step h, the installation preload (F) is used again. m The bolt system is pre-tightened.

4. The method according to one or more of the preceding claims, characterized in that, When the applied installation preload (F) m The overall stiffness (C) achieved is related to act The value of ) is less than that of the applied installation preload (F). m The overall stiffness (C) to be achieved is related to... target When the target value is reached, the bolt system is loosened after step h.

5. The method according to claim 4, characterized in that, After the bolt system is loosened, at least one sheet is inserted between the first flange and the second flange in the area of ​​the bolt system.

6. The method according to claim 5, characterized in that, Repeat steps g and h at least once.

7. The method according to one or more of the preceding claims, characterized in that, Before performing at least method steps h to i on the first bolt system, tighten all bolt systems of the flange connection to the specified installation preload (F). target Part of ).

8. The method according to one or more of the preceding claims, characterized in that, In each case, at least method steps g to h are first performed on the bolt system, in which case the gap between the first flange and the second flange is the largest.

9. The method according to one or more of the preceding claims, characterized in that, The specific boundary conditions are at least partially derived from the Markov matrix P used for the load state and local damage of the flange connection. Based on the Markov matrix P, the total damage value D for each bolt system is obtained. MAR The total damage value D MAR Less than 1.

10. The use of a bolt tensioning device, the bolt tensioning device comprising a housing, a tensioning unit, a distance measuring device, a tension determining device, and a calculation unit, wherein the overall stiffness (C) achieved can be measured by means of the bolt tensioning device. act The computing unit can store the overall stiffness (C) to be achieved, determined numerically and / or analytically. target ( ), used to implement the method according to one or more of the preceding claims.

11. A computer program product comprising a dataset, the dataset including at least one sequence of reference values, the sequence of reference values ​​being determined according to the following steps: a. Determine the flange parameters of at least the first and second flanges of the flange connection. b. Determine the axial stiffness (C) of the bolt by analyzing and identifying the typical elongation behavior of the bolt system. bolt ), and determine the axial stiffness of the flange body of the pre-tightened flange connection, c. Analysis and / or numerical analysis to specify the maximum permissible clearance size (S n This ensures that, considering specific boundary conditions, the fatigue damage of the bolt system does not exceed the defined total damage. d. Taking into account the previously determined maximum permissible clearance size (S) n ) and the installation preload force (F) that must be achieved during preload to ensure fatigue safety of the connection. m The overall stiffness (C) to be achieved by the tensioned flange body is determined through analysis. target ), in, The reference value sequence in each case reflects the overall stiffness (C0) to be achieved, determined through numerical and / or analytical methods. target ) and installation preload (F) m The target value of the relationship between the installation preload (F) applied to the bolt system and the target value of the relationship between the installation preload (F) and the target value of the bolt system. m The overall stiffness (C) achieved in relation to this act The value is compared with the target value, thereby enabling the computer program product to output a qualitative description of the flange connection at the location of the bolt system.

12. The computer program product according to claim 11, characterized in that, The computer program product prompts the user to tighten or loosen the nuts of the bolt system based on the qualitative description.

13. Use of a computer program product according to one or more of claims 11 to 12 in a method according to one or more of claims 1 to 9.

14. A storage medium comprising a dataset, the dataset including at least one sequence of reference values, each sequence of reference values ​​reflecting an overall stiffness (C0) to be achieved through numerical and / or analytical methods. target ) and installation preload (F) m The target value of the relationship, wherein the sequence of reference values ​​is determined according to the following steps: a. Determine the flange parameters of at least the first and second flanges of the flange connection. b. Determine the axial stiffness (C) of the bolt by analyzing and identifying the typical elongation behavior of the bolt system. bolt ), and determine the axial stiffness of the flange body of the pre-tightened flange connection, c. Analysis and / or numerical analysis to specify the maximum permissible clearance size (S n This ensures that, considering specific boundary conditions, the fatigue damage of the bolt system does not exceed the defined total damage. d. Taking into account the previously determined maximum permissible clearance size (S) n ) and the installation preload force (F) that must be achieved during preload to ensure fatigue safety of the connection. m The overall stiffness (C) to be achieved by the tensioned flange body is determined through analysis. target ), And / or a computer program product according to one or more of claims 12 to 13.