PTFE membrane material installation pretension control method and system

Abstract

The invention relates to the technical field of PTFE membrane material installation, and particularly provides a PTFE membrane material installation pretension control method and system.The method comprises the steps that real-time temperature information of different areas on a PTFE membrane material is obtained; for each area, acquiring additional thermal stress of the area according to the membrane material thermal expansion coefficient, the design reference temperature and the real-time temperature information; determining a temporary mechanical tension target corresponding to each area according to the additional thermal stress and a preset target total stress; for each area, tensioning operation is conducted on the PTFE membrane material according to the temporary mechanical tension target, the actual total stress of the area in the tensioning operation process is monitored in real time, and the tensioning operation is adjusted according to the deviation between the actual total stress and the target total stress till the total stress reaches the target total stress; the method can effectively peel off the influence of temperature change on the stress state of the membrane material and adjust the pretension target according to the dynamic temperature field.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of PTFE membrane installation, in particular to a PTFE membrane installation pre-tension control method and system. BACKGROUND

[0002] In large membrane structure projects, such as the construction of the roof of a stadium or exhibition center, PTFE (polytetrafluoroethylene) coated fiberglass membrane is widely used due to its excellent mechanical properties and durability. The pre-tension application stage is a key link to ensure the final form and long-term stability of the structure. With the increasing demand for precision and efficiency in the construction industry, related technologies continue to develop, aiming to achieve more precise construction control and higher structural reliability.

[0003] However, in actual construction process, significant changes in environmental temperature, especially uneven distribution of temperature on the membrane surface, will introduce thermal stress that is difficult to distinguish. Traditional control methods rely on macroscopic sensor feedback and pre-set mechanical calculations, but cannot effectively separate the influence of temperature effect. This results in the total stress value monitored containing the superposition of mechanical tension and thermal stress, making it difficult for construction personnel to accurately apply pure mechanical pre-tension. As a result, the pre-tension is unevenly distributed, deviating from the design intent, affecting the stability and durability of the structure. In the case of dramatic temperature changes, construction personnel face a dilemma: either resulting in insufficient mechanical tension, affecting future safety, or possibly exceeding material strength, causing damage. Existing methods lack a mechanism to separate temperature effects in real time by region, and cannot adjust the target according to the dynamic temperature field, so as to ensure that the final applied pure mechanical pre-tension can accurately and uniformly meet the design requirements under complex and changing environmental conditions.

[0004] There is currently no effective technical solution to the above problems. It should be noted that the above information disclosed in this part is only used to understand the background of the present application concept, and therefore can contain information that does not constitute prior art. SUMMARY

[0005] The purpose of the present application is to provide a PTFE membrane installation pre-tension control method and system, which can effectively separate the influence of temperature changes on the stress state of the membrane and adjust the pre-tension target according to the dynamic temperature field.

[0006] In a first aspect, the present application provides a PTFE membrane installation pre-tension control method, comprising the following steps: S1, obtaining real-time temperature information of different regions on the PTFE membrane; S2, for each region, obtaining the additional thermal stress of the region according to the thermal expansion coefficient of the membrane, the design reference temperature and the real-time temperature information; S3, determining a temporary mechanical tension target of each region according to the additional thermal stress and a preset target total stress; S4, for each region, performing a tensioning operation on the PTFE membrane material according to the temporary mechanical tension target, and monitoring an actual total stress of the region in the tensioning operation in real time, adjusting the tensioning operation according to a deviation between the actual total stress and the target total stress, until the total stress reaches the target total stress.

[0007] In a second aspect, the present application further provides a PTFE membrane material installation pre-tension control system, comprising: a temperature acquisition module, configured to acquire real-time temperature information of different regions of the PTFE membrane material; a thermal stress acquisition module, configured to acquire, for each region, an additional thermal stress of the region according to a membrane thermal expansion coefficient, a design reference temperature and the real-time temperature information; a tension target confirmation module, configured to determine a temporary mechanical tension target of each region according to the additional thermal stress and a preset target total stress; a tensioning module, configured to, for each region, perform a tensioning operation on the PTFE membrane material according to the temporary mechanical tension target, and monitor an actual total stress of the region in the tensioning operation in real time, adjust the tensioning operation according to a deviation between the actual total stress and the target total stress, until the total stress reaches the target total stress.

[0008] As can be seen from the above, the PTFE membrane material installation pre-tension control method and system provided by the present application can acquire the temperature information of different regions of the PTFE membrane material in real time, calculate the additional thermal stress according to the temperature information, dynamically adjust the temporary mechanical tension target of each region, and finally realize precise tensioning operation. Therefore, the present application can effectively eliminate the influence of temperature change on the stress state of the membrane material, and adjust the pre-tension target according to the dynamic temperature field, so as to ensure that the finally applied pure mechanical pre-tension can accurately and uniformly reach the design requirement under complex and changeable environmental conditions, thereby effectively improving the construction precision, safety and long-term stability of the PTFE membrane structure. BRIEF DESCRIPTION OF DRAWINGS

[0009] Figure 1 A flowchart of a PTFE membrane material installation pre-tension control method provided by an embodiment of the present application.

[0010] Figure 2 A schematic diagram of a PTFE membrane material installation pre-tension control method provided by an embodiment of the present application.

[0011] Figure 3 A structural schematic diagram of a PTFE membrane material installation pre-tension control system provided by an embodiment of the present application.

[0012] Reference numerals: 1, temperature acquisition module; 2, thermal stress acquisition module; 3, tension target confirmation module; 4, tensioning module. DETAILED DESCRIPTION

[0013] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application.

[0014] It should be noted that: similar reference numerals and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. Meanwhile, in the description of the present application, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0015] In a first aspect, as shown in Figure 1 and Figure 2 The present application provides a PTFE membrane installation pre-tension control method, which comprises the following steps: S1, acquiring real-time temperature information of different regions on the PTFE membrane; S2, for each region, acquiring additional thermal stress of the region according to the thermal expansion coefficient of the membrane, the design reference temperature and the real-time temperature information; S3, determining the temporary mechanical tension target corresponding to each region according to the additional thermal stress and the preset target total stress; S4, for each region, performing tensioning operation on the PTFE membrane according to the temporary mechanical tension target, and monitoring the actual total stress of the region in the tensioning operation process in real time, adjusting the tensioning operation according to the deviation between the actual total stress and the target total stress, until the total stress reaches the target total stress.

[0016] The PTFE membrane material of this embodiment is preferably a polytetrafluoroethylene-coated glass fiber membrane, which is a flexible building material commonly used in membrane structure engineering. The real-time temperature information of this embodiment refers to the temperature data of the surface or interior of the membrane material collected in real time by sensors and other devices during the installation of the membrane material. The thermal expansion coefficient of the membrane material of this embodiment refers to the proportional coefficient of the change in size of the PTFE membrane material when the temperature changes, which is a physical property inherent to the material. The design reference temperature of this embodiment refers to the reference temperature used to calculate the stress state of the membrane material during the design phase of the membrane structure, which is preferably the average ambient temperature or a specific design temperature of the PTFE membrane material after it is put into use. The additional thermal stress of this embodiment refers to the additional stress generated by the restriction of the thermal expansion or contraction of the PTFE membrane material due to the difference between the actual temperature of the membrane material and the design reference temperature. The target total stress of this embodiment is preferably the final total stress value that the PTFE membrane material should reach at the design reference temperature as specified in the design document of the PTFE membrane material. The temporary mechanical tension target of this embodiment refers to the target value of the mechanical tension that needs to be applied to the PTFE membrane material in order to make the final total stress of the PTFE membrane material reach the target total stress after considering the additional thermal stress caused by the current real-time temperature. The tensioning operation of this embodiment refers to the construction process of applying tension to the PTFE membrane material by tensioning equipment to make it reach a predetermined tension state (the final total stress reaches the target total stress). The actual total stress of this embodiment refers to the current total stress value of the membrane material monitored in real time by sensors during the actual tensioning operation, which includes mechanical stress and thermal stress.

[0017] The application provides a PTFE membrane installation pre-tension control method, and the specific implementation manner can be described as follows: first, in step S1, the real-time temperature information of different regions on the PTFE membrane can be obtained in the following manner: 1. Real-time temperature data of each region can be collected by pre-setting multiple temperature sensors on the surface or inside the PTFE membrane, which can be thermocouples, thermistors or infrared thermometers, etc. These sensors are arranged at different positions of the PTFE membrane to cover the entire PTFE membrane region, so as to obtain real-time temperature information with spatial distribution characteristics; 2. An infrared thermal imager is carried by a drone to scan the entire PTFE membrane, and then a temperature distribution map of the membrane surface is obtained by image processing technology to obtain real-time temperature information of different regions; 3. The temperature of different regions of the PTFE membrane is measured by using a handheld thermometer in a manual inspection manner, and the corresponding temperature data is recorded. Secondly, in step S2, for each region, the additional thermal stress of the region is obtained according to the membrane thermal expansion coefficient, the design reference temperature and the real-time temperature information. Specifically, the thermal expansion coefficient (membrane thermal expansion coefficient) and the elastic modulus of the PTFE membrane can be obtained by experiment or reference in advance, for each region for which the real-time temperature information has been obtained, the real-time temperature of the region is compared with the design reference temperature to calculate the temperature difference, and then the elastic modulus and the thermal expansion coefficient of the membrane are used to calculate the additional thermal stress of the region by combining the temperature difference through a thermal stress calculation formula (additional thermal stress = elastic modulus x thermal expansion coefficient x temperature difference). It should be understood that step S2 can also quickly determine the additional thermal stress by querying a pre-constructed lookup table according to the membrane thermal expansion coefficient, the design reference temperature and the real-time temperature information, the lookup table stores the corresponding additional thermal stress under the combination of different temperature differences and membrane thermal expansion coefficients, step S2 can also obtain the additional thermal stress by inputting the membrane thermal expansion coefficient, the design reference temperature and the real-time temperature information into a numerical simulation software, and the numerical simulation software preferably calculates the additional thermal stress by finite element analysis or the like. Then, in step S3, the temporary mechanical tension target corresponding to each region is determined according to the additional thermal stress and the preset target total stress. Specifically, since the actual monitored total stress is the superposition of the mechanical tension and the additional thermal stress, in order to make the final total stress reach the target total stress required by the design, the additional thermal stress needs to be separated from the target total stress, therefore, for each region, the temporary mechanical tension target can be obtained by subtracting the additional thermal stress of the region from the preset target total stress (i.e. temporary mechanical tension target = target total stress - additional thermal stress). Finally, in step S4, for each region, the PTFE membrane is tensioned according to the temporary mechanical tension target, and the actual total stress of the region during the tensioning operation is monitored in real time, and the tensioning operation is adjusted according to the deviation of the actual total stress from the target total stress until the total stress reaches the target total stress.Specifically, the tensioning operation can be performed by hydraulic jacks, electric hoists or special tensioning equipment, etc. During the tensioning operation, the actual total stress in the region is monitored in real time by force sensors installed on the membrane material or tensioning cables. The control system compares the actual total stress monitored in real time with the preset target total stress, calculates the deviation between the two, and if the deviation exceeds the allowable range, the control system will issue instructions to the tensioning equipment to adjust the size of the tensioning force or the tensioning speed to reduce the deviation. For example, when the actual total stress is lower than the target total stress, the tensioning force can be increased; when the actual total stress is higher than the target total stress, the tensioning force can be appropriately reduced or the current tensioning force can be maintained to wait for the creep of the membrane material. This adjustment process is iterative until the actual total stress in the region reaches the target total stress.

[0018] The PTFE membrane installation pre-tension control method disclosed in the present application has the core innovation of obtaining the temperature information of different regions of the PTFE membrane in real time, calculating the additional thermal stress according to the temperature information, dynamically adjusting the temporary mechanical tension target of each region, and finally realizing precise tensioning operation. Therefore, the present application can effectively eliminate the influence of temperature change on the stress state of the membrane material and adjust the pre-tension target according to the dynamic temperature field to ensure that the final pure mechanical pre-tension applied under complex and variable environmental conditions can accurately and uniformly meet the design requirements, thereby effectively improving the construction precision, safety and long-term stability of the PTFE membrane structure.

[0019] The method effectively solves the problem of thermal stress interfering with the accuracy of pre-tension application during the installation of PTFE membrane material through the closed-loop process of "real-time temperature sensing - additional thermal stress calculation - dynamic adjustment of temporary mechanical tension target - real-time feedback tensioning control". Each step is closely coordinated and related, and together forms a complete technical system that can adapt to complex environments and achieve high-precision pre-tension control, ensuring that the final stress state of the membrane structure under different temperature conditions can meet the design requirements, thereby significantly improving the construction quality, safety and long-term stability of the membrane structure. Therefore, compared with the traditional existing pre-tension control method, the present application has significant advantages.

[0020] The application realizes accurate quantification and peeling of temperature influence by introducing real-time temperature information of different areas on the PTFE film material and calculating additional thermal stress of each area according to the real-time temperature information (steps S1 and S2). On this basis, step S3 dynamically determines the temporary mechanical tension target of each area according to the additional thermal stress and the preset target total stress, which enables the tension target to adapt to the change of the ambient temperature in real time. Finally, the real-time monitoring and adjustment mechanism of step S4 ensures that the tension operation can accurately adjust the total stress of the film material to the target total stress. Thus, the application overcomes the difficulty of distinguishing and compensating thermal stress in the traditional method, that is, the application can ensure that the final applied pure mechanical pretension can accurately and uniformly meet the design requirements under complex and variable environmental conditions, thereby significantly improving the precision and efficiency of PTFE film installation and effectively avoiding the pretension deviation caused by temperature change, and effectively improving the overall safety and service life of the membrane structure.

[0021] The above embodiment usually relies on a preset or empirical thermal expansion coefficient of the film material when obtaining the additional thermal stress. However, the actual thermal expansion coefficient of the PTFE film material may be affected by various factors such as material batch, production process, environmental humidity, and long-term use, resulting in deviation between the preset coefficient and the actual situation. If the above problem is not solved, the additional thermal stress calculated based on the inaccurate thermal expansion coefficient will not be accurate, which will affect the determination of the subsequent temporary mechanical tension target, and may cause the PTFE film material to fail to reach the ideal pretension state during installation, and even cause uneven stress distribution of the structure or damage to the film material.

[0022] To solve the technical problem, in some preferred embodiments, step S2 comprises: S21, for each area, a preset pretension is applied to the PTFE film material, and the mechanical stroke of the tensioning device is locked, and the preset pretension is less than the target total stress; S22, for each area, the tension change and temperature change of the PTFE film material are collected; S23, for each area, the actual thermal expansion coefficient of the PTFE film material in the area is determined according to the tension change and the temperature change; S24, for each area, the additional thermal stress of the area is obtained according to the actual thermal expansion coefficient, the design reference temperature and the real-time temperature information.

[0023] The purpose of step S21 is to make the membrane material enter a stable stress state so as to accurately measure its thermal expansion characteristics. The preset pretension is set to be less than the target total stress to avoid excessive stress on the membrane material during the measurement stage, while leaving room for subsequent tensioning operations. The purpose of locking the mechanical stroke of the tensioning equipment in step S21 is to simulate the state of the membrane material after being fixed during the actual installation process, so as to ensure that the length change of the membrane material directly translates into a change in tension when the temperature changes, thereby more accurately reflecting its thermal expansion characteristics. Step S22 can use the tension sensor and temperature sensor arranged on or near the surface of the PTFE membrane material to collect the tension change and temperature change of the PTFE membrane material. Specifically, the tension sensor is used to monitor the stress of the PTFE membrane material in real time, and the temperature sensor is used to obtain the local temperature of the PTFE membrane material. The collection of these data is the basis for determining the actual thermal expansion coefficient. Step S23 involves the application of principles of material mechanics and thermodynamics, for example, under the condition of mechanical stroke locking, the tension change of the PTFE membrane material is mainly caused by thermal expansion or contraction caused by temperature change, so step S23 can deduce the actual thermal expansion coefficient of the membrane material in this region by analyzing the relationship between tension and temperature. Step S24 can accurately obtain the additional thermal stress in this region according to the determined actual thermal expansion coefficient, the design reference temperature and the real-time temperature information. That is, this embodiment enables the additional thermal stress to be more accurately calculated as the additional stress caused by the temperature deviation of the membrane material from the design reference temperature.

[0024] The scheme of the present application effectively solves the calculation deviation problem of the additional thermal stress caused by the inaccuracy of the thermal expansion coefficient in the traditional method by introducing the dynamic determination of the actual thermal expansion coefficient of the PTFE membrane material. Specifically, in step S21, a controlled environment is created for subsequent measurement by applying a preset pretension to the PTFE membrane material and locking the mechanical stroke of the tensioning equipment. In this controlled environment, the length change of the membrane material is limited, and the thermal expansion or contraction caused by temperature change will directly translate into a change in tension. Subsequently, in step S22, direct data reflecting the thermodynamic response of the membrane material is obtained by collecting the tension change and temperature change of the membrane material in real time. In step S23, the actual thermal expansion coefficient of the PTFE membrane material in this region is reversely deduced according to the accurate tension and temperature change data combined with the principles of mechanics. Finally, step S24 uses this more actual actual thermal expansion coefficient to calculate a more accurate additional thermal stress combined with the design reference temperature and real-time temperature information. This method of dynamically obtaining the actual thermal expansion coefficient avoids errors that may be caused by using fixed or empirical values, thereby ensuring the accuracy of the calculation of the additional thermal stress.

[0025] By the technical solution, the precision and reliability of the installation pre-tension control of the PTFE membrane material can be improved. Since the actual thermal expansion coefficient of the PTFE membrane material is dynamically and accurately determined, the calculated additional thermal stress is more consistent with the real stress state of the PTFE membrane material under the current environment, so that the subsequent determined temporary mechanical tension target can more accurately compensate the stress influence caused by the temperature change, thereby ensuring that the PTFE membrane material can achieve more uniform and stable pre-tension distribution after installation. Compared with the method of calculating the additional thermal stress by relying on the preset or empirical thermal expansion coefficient, the application can effectively avoid the tension deviation caused by the inaccurate coefficient, reduce the risk of stress concentration, local over-tension or under-tension in the membrane material installation process, thereby prolonging the service life of the membrane structure and improving the safety and aesthetics of the overall structure.

[0026] In some preferred embodiments, the following is described by a specific example. Assuming that during the installation process of a PTFE membrane structure in a large sports venue, the pre-tension control of a specific area of the membrane material is required. First, in step S21, the construction personnel will use the tensioning equipment to apply a preset pre-tension to the PTFE membrane material in the area, for example, set to 40% of the target total stress, and then lock the mechanical stroke of the tensioning equipment to ensure that the length of the membrane material in the area does not change due to mechanical operation. Then, in step S22, the tension sensor and temperature sensor pre-installed on the surface of the membrane material will start to work in real time, for example, within one hour after locking the stroke, the sensor collects the tension reading and temperature reading of the membrane material every 5 minutes. Assuming that within this one hour, the temperature of the membrane material rises from 20℃ to 22℃, and the tension reading changes from 100kN to 102kN. Then, in step S23, the control system will calculate the actual thermal expansion coefficient of the PTFE membrane material in the area according to the collected tension change (2kN) and temperature change (2℃), combined with the preset parameters such as the cross-sectional area and initial length of the membrane material, through the preset mechanical model (for example, based on the combination of Hooke's law and thermal expansion formula). For example, the calculation result shows that the actual thermal expansion coefficient of the area is 1.5x10 -5 / ℃, which may be different from the general design value of PTFE material (for example, 1.2x10 -5 / ℃).

[0027] Finally, in step S24, the system will use this newly determined actual thermal expansion coefficient (1.5x10 -5 / ℃), combined with the design reference temperature (for example, 25℃) and the current real-time temperature information (for example, 22℃), to accurately calculate the additional thermal stress of the area. In this way, a more actual additional thermal stress value can be obtained, providing more accurate input for the subsequent determination of the temporary mechanical tension target.

[0028] In some embodiments of the present application, it is proposed that the tension change amount and the temperature change amount of the PTFE membrane material need to be collected when determining the additional thermal stress. However, in the actual membrane installation and pre-tension control process, the internal stress distribution of the PTFE membrane material and the mechanical state of the tensioning equipment may not be completely stable after the preset pre-tension is applied. If the tension change amount and the temperature change amount are collected directly when the membrane or the tensioning equipment is in an unstable state, the data obtained may contain transient fluctuations caused by non-thermal expansion or mechanical errors, thereby affecting the accuracy of subsequent actual thermal expansion coefficient determination. If the above problem is not solved, it may lead to inaccurate calculation of the additional thermal stress, thereby affecting the setting accuracy of the final temporary mechanical tension target and reducing the overall effect of the pre-tension control.

[0029] To solve the technical problem, in some preferred embodiments, step S22 comprises: S221, for each region, obtaining the tension change rate of the PTFE membrane material in the region within a preset time window, and obtaining the actual mechanical stroke of the tensioning equipment; S222, for each region, when the tension change rate is less than a preset stability threshold and the deviation of the actual mechanical stroke from the preset mechanical stroke is less than a preset stroke deviation, collecting the tension change amount and the temperature change amount of the PTFE membrane material.

[0030] The tension change rate of the PTFE membrane material within a preset time window refers to continuously monitoring the tension data of the membrane material and calculating the change trend and speed of the tension within a certain time period. For example, a 5-second or 10-second preset time window can be set, and the data collected by the tension sensor within this window is linearly fitted or differentially calculated to obtain the average tension change rate. This tension change rate is used to evaluate whether the membrane material is currently in a tension stable state. The actual mechanical stroke of the tensioning device refers to real-time monitoring of the displacement or position information of the tensioning device (such as winch, hydraulic cylinder, etc.) to determine whether it has reached the preset locking position or is still being fine-tuned. The preset stable threshold is a critical value for determining whether the tension is stable. When the tension change rate is lower than the threshold, it is considered that the tension of the membrane material has tended to be stable. For example, the threshold can be set to 0.01 N / s or 0.005 MPa / s. It should be understood that the specific value of the preset stable threshold can be determined according to the characteristics of the membrane material and engineering experience. The preset mechanical stroke is the theoretical locking position that the tensioning device should reach after applying the preset pretension, and the preset stroke deviation is the maximum allowable error range that the actual mechanical stroke is allowed to deviate from the preset mechanical stroke, for example, it can be set to ±1 mm or ±0.5 mm. When both the tension change rate and the mechanical stroke deviation meet the preset conditions, it indicates that the membrane material and the tensioning device have both reached a relatively stable state, and the tension change amount and the temperature change amount collected at this time can more accurately reflect the thermal expansion characteristics of the membrane material, so as to avoid measurement errors caused by system instability.

[0031] The scheme of the present application realizes intelligent judgment of data acquisition time by introducing monitoring of the tension change rate and the actual mechanical stroke of the tensioning device. After a preset pretension is applied and the mechanical stroke of the tensioning device is locked, the PTFE membrane material and the tensioning system may need a certain time to completely stabilize. By continuously obtaining the tension change rate of the membrane material, it can be evaluated in real time whether the internal stress of the membrane material has tended to balance; at the same time, by obtaining the actual mechanical stroke of the tensioning device and comparing it with the preset mechanical stroke, it can be judged whether the tensioning device has been accurately positioned and kept stable. Only when the tension change rate is less than the preset stable threshold and the deviation of the actual mechanical stroke from the preset mechanical stroke is less than the preset stroke deviation (indicating that the membrane tension fluctuation is extremely small and the tensioning device has been stably locked), will the embodiment collect the tension change amount and the temperature change amount. This conditional data collection based on the stable state of the system can effectively filter out measurement noise caused by factors such as membrane creep, equipment fine adjustment or environmental transient disturbance, ensuring the purity and accuracy of the collected data. Through the above technical scheme, the present application can significantly improve the accuracy and reliability of the data collection of the tension change amount and the temperature change amount of the PTFE membrane. Compared with directly collecting data without distinction, the present scheme effectively avoids measurement errors caused by unstable membrane or tensioning device by collecting data only when the system reaches a stable state. Thus, the actual thermal expansion coefficient of the PTFE membrane can be more accurately determined, and the subsequent calculation of additional thermal stress is more accurate, ultimately ensuring that the setting of the temporary mechanical tension target is more reasonable and accurate. This is of great significance to the long-term structural safety and performance stability of the PTFE membrane, effectively improving the precision and reliability of the entire installation pretension control method.

[0032] In some preferred embodiments, the following is described by a specific example. Assuming that after a preset pretension is applied to the PTFE membrane of a certain area and the mechanical stroke of the tensioning device is locked, the system starts to continuously monitor the tension change rate of the area and the actual mechanical stroke of the tensioning device. For example, a preset time window of 10 seconds, a preset stable threshold of 0.008 N / s, a preset mechanical stroke of 1000 mm, and a preset stroke deviation of ±0.5 mm can be set. The system will collect tension data and mechanical stroke data every 1 second. Within the continuous 10 seconds, if the calculated tension change rate is less than 0.008 N / s and the actual mechanical stroke of the tensioning device always remains between 999.5 mm and 1000.5 mm, it is considered that the membrane and the tensioning device of the area have reached a stable state. At this time, the system will trigger the data acquisition module to accurately record the tension change amount and the temperature change amount at the current time. If the above conditions are not met at the same time, the system will continue to monitor until the data collection is performed after the conditions are met. In this way, the original data used to calculate the actual thermal expansion coefficient is obtained under stable conditions that best reflect the thermodynamic properties of the membrane.

[0033] In some embodiments of the application described above, the actual thermal expansion coefficient of the PTFE film material is determined according to the tension change and the temperature change. However, in practical applications, the mechanical properties of the PTFE film material are complex, and the tension change is not only affected by the temperature, but also closely related to the stiffness of the material. If the thermal expansion coefficient is determined only by the tension change and the temperature change, the real thermal expansion behavior of the material under actual stress state may not be fully reflected, thereby affecting the accuracy of the additional thermal stress calculation.

[0034] To solve the technical problem, in some preferred embodiments, step S23 comprises: S231, for each region, a preset displacement disturbance is applied to the PTFE film material in the state of mechanical stroke locking of the tensioning device, and the tension response of the PTFE film material to the preset displacement disturbance is monitored; S232, for each region, the effective stiffness of the PTFE film material in the region is determined according to the preset displacement disturbance and the tension response, and then the actual thermal expansion coefficient of the PTFE film material in the region is determined according to the tension change, the temperature change and the effective stiffness.

[0035] The step S231 of applying a preset displacement disturbance to the PTFE membrane material refers to applying a known small displacement to the PTFE membrane material through an external device or a fine adjustment mechanism of the tensioning equipment itself when the mechanical stroke of the tensioning equipment is locked. For example, a preset and controllable small tensile or compressive displacement can be applied to a specific area of the membrane material through a hydraulic jack or a servo motor driven fine adjustment mechanism. At the same time, the tension response of the PTFE membrane material to the preset displacement disturbance is monitored by measuring the change in tension of the membrane material in real time when it is subjected to the displacement disturbance through the force sensor installed on the membrane material or the tensioning equipment, so as to obtain the mechanical response characteristics of the PTFE membrane material in the current state and provide a data basis for subsequent stiffness calculation. The step S232 of determining the effective stiffness of the PTFE membrane material in the area according to the preset displacement disturbance and the tension response can be understood as calculating the elastic modulus or equivalent stiffness of the material by measuring the relationship between force and displacement. The effective stiffness can be represented by the slope of the stress-strain curve or approximated by a simple force / displacement ratio, and the effective stiffness can reflect the ability of the PTFE membrane material to resist deformation under the current stress state. Subsequently, the actual thermal expansion coefficient of the PTFE membrane material in the area is determined according to the amount of change in tension, the amount of change in temperature and the effective stiffness. This means that when calculating the thermal expansion coefficient, it is no longer dependent only on the linear relationship between tension and temperature, but takes into account the actual stiffness of the membrane material. For example, an equation set containing tension, temperature, displacement and stiffness parameters is established based on the basic principles of thermodynamics and the material mechanics model, and the actual thermal expansion coefficient is accurately calculated by solving the equation set, so as to effectively improve the accuracy of the thermal expansion coefficient calculation, so that the thermal expansion coefficient is more in line with the complex mechanical behavior of the PTFE membrane material in the actual installation process.

[0036] The scheme of the present application solves the problem of insufficient precision in the traditional method by introducing the concept of effective stiffness when determining the actual thermal expansion coefficient of the PTFE film material. As a flexible material, the mechanical properties of the PTFE film material are affected by various factors, and simply calculating the thermal expansion coefficient by the tension change and temperature change may ignore the nonlinear elastic behavior of the material under different stress states. By applying a preset displacement disturbance and monitoring the tension response, the effective stiffness of the film material under the current installation state can be obtained in real time and dynamically, which enables the calculation of the thermal expansion coefficient to fully consider the actual deformation characteristics and mechanical response of the film material. It is precisely because the actual stiffness of the film material is included in the calculation model that the determined actual thermal expansion coefficient is more accurate, thereby providing more reliable basic data for the subsequent calculation of additional thermal stress. Through the above technical scheme, the present application can more accurately determine the actual thermal expansion coefficient of the PTFE film material. Compared with the method relying only on the tension change and temperature change, the present scheme introduces the measurement and calculation of the effective stiffness of the film material, which makes up for the deficiency of the traditional method in considering the complex mechanical behavior of the material, which makes the calculated additional thermal stress more accurate, thereby providing a more reliable basis for subsequent temporary mechanical tension target determination and tensioning operation, effectively avoiding the tension deviation caused by inaccurate estimation of the thermal expansion coefficient, and improving the overall precision and reliability of the PTFE film material installation pre-tension control.

[0037] In some preferred embodiments, the following is described by a specific example. Assuming that the tensioning operation is performed on a certain area of the PTFE film material, when the mechanical stroke of the tensioning device is locked, in order to determine the actual thermal expansion coefficient of the area, the following steps can be taken: first, a micro-hydraulic actuator controlled by a high-precision displacement sensor is used to apply a preset displacement disturbance of, for example, 0.5 mm to the PTFE film material in the area. At the same time, a tension sensor installed on the edge of the film material is used to monitor the tension response of the film material in real time, for example, recording that the tension increases by 100 Newtons. From this, the effective stiffness of the area can be calculated as 200 Newtons / mm. Subsequently, the previously collected tension change (for example, the tension decreases by 500 Newtons due to temperature change) and temperature change (for example, the temperature increases by 10 degrees Celsius) and the effective stiffness are substituted into the pre-established material mechanics model to accurately solve the actual thermal expansion coefficient of the PTFE film material in the area. Specifically, the model can be a nonlinear equation based on finite element analysis or empirical formula, which is solved by iterative calculation or numerical method. In this way, the determined thermal expansion coefficient can more truly reflect the thermodynamic characteristics of the film material under the actual installation environment, thereby ensuring more accurate subsequent tension control.

[0038] In some embodiments of the present application, a method is provided for determining the temporary mechanical tension target of each region according to the additional thermal stress, the preset target total stress, the thermal expansion coefficient of the film material, the design reference temperature and the real-time temperature information. However, in the actual installation process of the PTFE film material, the tensions between different regions of the film material interact with each other. If the temporary mechanical tension target of each region is simply determined independently, the preset stress distribution of the overall film material may not be accurately achieved, and even local stress concentration or deficiency may occur, affecting the structural stability and service life of the film material.

[0039] To solve the technical problem, in some preferred embodiments, step S3 comprises: S31, selecting any region whose temporary mechanical tension target has not been determined; S32, obtaining the tension influence amount of the region whose temporary mechanical tension target has been determined on the currently selected region according to the positions of all the regions whose tension has been completed and their corresponding actual tension data, the positions of all the regions whose temporary mechanical tension target has been determined and their corresponding temporary mechanical tension targets, the position of the currently selected region and the corresponding preset mechanical transmission characteristics of the PTFE film material; S33, determining the temporary mechanical tension target corresponding to the currently selected region according to the additional thermal stress, the tension influence amount and the preset target total stress; S34, analyzing whether there is still a region whose temporary mechanical tension target has not been determined, if yes, returning to step S31, and if no, executing step S4.

[0040] Step S31 aims to start the process of determining the temporary mechanical tension target of the film material region to ensure that all regions can be systematically processed. Step S32 is the key of the present scheme, which is to obtain the tension influence quantity, which can be understood as the mechanical coupling effect of the tension state of the region that has completed tensioning or has determined the temporary mechanical tension target on the region whose temporary mechanical tension target is currently to be determined in the overall structure of the PTFE film material. Specifically, this influence quantity is calculated by comprehensively considering the geographical position of these regions, their current actual tension data (for regions that have completed tensioning) or the determined temporary mechanical tension target (for regions that have determined the target but have not yet been tensioned), and the inherent preset mechanical transmission characteristics of the PTFE film material. The preset mechanical transmission characteristics can be a pre-established mechanical model, such as a model constructed based on finite element analysis (FEA) or empirical data, which can describe how force is transmitted and distributed in the entire film material structure when force is applied at different points. Step S32 is equivalent to quantifying the interaction between different parts of the PTFE film material to provide more comprehensive information for subsequent tension target determination. Step S33 determines the temporary mechanical tension target corresponding to the currently selected region according to the additional thermal stress, the tension influence quantity and the preset target total stress, i.e. the temporary mechanical tension target corresponding to the currently selected region is no longer determined only by the additional thermal stress of the region itself and the preset target total stress, but further considers the tension influence from other regions, which means that when determining the tension target of a region, the system will subtract or add the tension influence from other regions to ensure that the final temporary mechanical tension target can offset or compensate for these influences, so that the actual total stress of the region can more accurately approach the preset target total stress after tensioning operation according to the temporary mechanical tension target. Step S34 ensures the integrity of the entire determination process. By looping to determine whether the temporary mechanical tension target of all regions has been determined, this method can ensure that the tension target of the entire PTFE film material is systematically and comprehensively planned until the temporary mechanical tension target of all regions is reasonably determined.

[0041] The scheme of the present application effectively solves the problem of insufficient precision caused by independently determining the tension targets of each region in the traditional method by introducing the consideration of the tension influence quantity between different regions of the membrane material. Specifically, when determining the temporary mechanical tension target of a certain region, the tension influence quantity of the current region caused by other processed regions (including regions that have completed tensioning and have determined targets) is calculated through step S32, instead of only based on the additional thermal stress of the region itself and the preset target total stress. This tension influence quantity reflects the complexity of the internal mechanical transmission of the membrane material as a whole structure. By including this influence quantity in the calculation of step S33, i.e., subtracting or adding the influence quantity from the preset target total stress, and combining the additional thermal stress to determine the temporary mechanical tension target, the determined temporary mechanical tension target can more accurately reflect the actual demand of the current region under the overall membrane stress balance state. This iterative and interaction-considering mechanism ensures that the tension targets of each region are mutually coordinated and globally optimized during the entire tensioning process of the membrane material, thereby avoiding local stress deviation and improving the accuracy of overall tension control.

[0042] Through the above technical scheme, the present application can significantly improve the accuracy and reliability of the installation pre-tension control of the PTFE membrane material. By considering the tension influence quantity between different regions of the membrane material when determining the temporary mechanical tension target, the method can more realistically reflect the mechanical behavior of the membrane material under the overall stress state, thereby avoiding local stress deviation caused by ignoring the interaction between regions. This enables the final tensioning operation to more accurately make the membrane material achieve the designed overall stress distribution, effectively reducing the risk of local stress concentration or deficiency, and thereby improving the overall stability and safety of the PTFE membrane structure, prolonging its service life.

[0043] In some preferred embodiments, the following is described by a specific example. Assume that a large PTFE membrane structure is divided into multiple tensioning areas, such as area A, area B, area C, etc. First, the system selects area C as the current to-be-processed area. Then, the system obtains the actual tension data of all completed tensioning areas (for example, area A), and the temporary mechanical tension target of all areas (for example, area B) that have determined the temporary mechanical tension target but have not been tensioned. At the same time, combined with the position information of these areas and the pre-set mechanical transmission characteristic model of the PTFE membrane, the tension influence amount of area A and area B on area C is calculated. For example, if the tensioning of area A causes the natural increase of the tension of area C, the influence amount is positive; otherwise, if it causes the decrease of the tension, the influence amount is negative. Then, when determining the temporary mechanical tension target of area C, the system will comprehensively operate the additional thermal stress of area C itself, the pre-set target total stress, and the calculated tension influence amount. For example, if the target total stress is 100 kPa, the additional thermal stress is 10 kPa, and the tension influence of area A and B on area C is 5 kPa (i.e. without applying mechanical tension, the stress of area C has reached 5 kPa due to the tensioning of A and B), then the temporary mechanical tension target of area C can be set to 100 kPa-10 kPa-5 kPa=85 kPa. In this way, it is ensured that when area C is tensioned, the final total stress can more accurately reach the target value of 100 kPa, while considering the interaction of other areas. This process is iterated until the temporary mechanical tension targets of all areas are determined, thereby realizing the accurate pre-tension control of the entire membrane structure.

[0044] In some embodiments of the present application described above, when determining the temporary mechanical tension target corresponding to each area, it is necessary to obtain the tension influence of the area whose temporary mechanical tension target has been determined on the currently selected area according to the pre-set mechanical transmission characteristic corresponding to the PTFE membrane. However, in the actual installation process, the mechanical transmission characteristic of the PTFE membrane may be affected by environmental factors (such as wind load and temperature distribution) and change. If only the pre-set static mechanical transmission characteristic is used, the calculation of the tension influence may not be accurate enough, thereby affecting the accuracy of the final tensioning effect.

[0045] To solve the technical problem, in some preferred embodiments, step S32 comprises: S321, obtaining environmental wind load and temperature distribution information of the PTFE membrane; S322, correcting the pre-set mechanical transmission characteristic corresponding to the PTFE membrane according to the environmental wind load and the temperature distribution information, to obtain a corrected mechanical transmission characteristic; S323、According to the positions of all completed tensioning areas and their corresponding actual tension data, the positions of all areas with determined temporary mechanical tension targets and their corresponding temporary mechanical tension targets, the position of the currently selected area, and the revised mechanical transfer characteristic, the tension influence of the areas with determined temporary mechanical tension targets on the currently selected area is obtained.

[0046] In step S321, the environmental wind load can be obtained by real-time monitoring through the deployment of wind speed and direction sensors on the construction site, or by real-time meteorological data provided by the meteorological department. The temperature distribution information of the PTFE membrane material can be obtained by arranging an array of temperature sensors on the surface of the membrane material to collect temperature data of different areas in real time. In step S322, the pre-set mechanical transfer characteristic is usually a membrane material mechanical response model determined under ideal conditions or through preliminary tests. In actual application, wind load and temperature distribution will affect the stiffness and deformation characteristics of the membrane material. Therefore, the revised mechanical transfer characteristic refers to a mechanical transfer model that is more in line with the actual working conditions after adjusting and optimizing the pre-set mechanical transfer characteristic considering the current environmental wind load and temperature distribution. For example, by establishing a finite element model of the membrane material, the real-time acquired environmental wind load and temperature distribution are input as boundary conditions, the mechanical response of the membrane material under the current environment is obtained through simulation calculation, and then the mechanical transfer characteristic is revised. In step S323, the revised mechanical transfer characteristic is used to more accurately calculate the tension influence of the completed tensioning areas or the areas with determined temporary mechanical tension targets on the currently selected area, to ensure that the influence of environmental factors on the overall stress state of the membrane material can be fully considered when determining the temporary mechanical tension target of the current area.

[0047] The scheme of the present application solves the problem of the static and disconnection with the actual environment of the mechanical transmission characteristics in the traditional method by introducing the environmental wind load and the temperature distribution information of the PTFE membrane material and correcting the preset mechanical transmission characteristics based on these real-time environmental data. Specifically, the wind load will cause additional deformation and stress of the membrane material, and the temperature change will cause thermal expansion and contraction of the membrane material, thereby affecting its overall stiffness and tension distribution. By real-time acquisition and utilization of these environmental factors to correct the mechanical transmission characteristics, the mechanical model used can more accurately reflect the real stress behavior of the membrane material under the current construction environment. Thus, when calculating the tension influence amount of the current to-be-tensioned region on the already tensioned region or the tension target region determined, more accurate results can be obtained, avoiding calculation deviation caused by environmental factors. Since the influence of environmental wind load and temperature distribution on the mechanical transmission characteristics of the membrane material is considered to make the calculation of the tension influence amount more close to the actual working condition, the scheme can more accurately determine the temporary mechanical tension target of each region, thereby improving the accuracy and reliability of the entire tensioning process and avoiding tension deviation caused by environmental changes to ensure that the PTFE membrane material reaches the designed overall stress state after installation, thereby effectively reducing the construction risk and effectively improving the overall quality and safety of the membrane structure project.

[0048] In some preferred embodiments, the following is described by a specific example. Assuming that in the installation process of a large sports venue PTFE membrane structure, the membrane material needs to be pre-tensioned. In step S321, wind speed and direction sensors and temperature sensors can be installed at different positions on the construction site to obtain real-time environmental wind load data and temperature distribution data of the membrane material in the region. In step S322, the control system will dynamically correct the preset mechanical transmission characteristics of the membrane material according to these real-time environmental data combined with the preset mechanical model of the membrane material (for example, a model established based on finite element analysis). For example, if the wind load is large, the corrected mechanical transmission characteristics may reflect the change in stiffness of the membrane material under wind pressure; if the temperature rises, the corrected mechanical transmission characteristics may reflect the stress relaxation or increase caused by thermal expansion of the membrane material. Subsequently, in step S323, using these corrected mechanical transmission characteristics, the system can more accurately calculate the tension influence amount of the current to-be-tensioned region on the already tensioned region. For example, when calculating the temporary mechanical tension target of a region that has not been tensioned, the system will consider how the actual tension of the adjacent already tensioned region is transmitted to this region through the corrected mechanical characteristics of the membrane material under the current wind load and temperature distribution. In this way, it can be ensured that the temporary mechanical tension target set for each region is dynamically adjusted and can adapt to the changing environmental conditions on the construction site, thereby achieving more accurate pre-tensioning control.

[0049] In some embodiments of the present application, when determining the temporary mechanical tension target of each region, the preset target total stress may be directly used for calculation. However, in the actual installation process of the PTFE membrane material, the state of the structure is dynamically changing. For example, in different installation stages, the geometric shape of the membrane material and the stress state of the main steel structure member may be different. If the real-time structural state information is not fully considered and the fixed target total stress is directly used, the tension operation may not match the actual structural bearing capacity, thereby affecting the installation precision, the structural safety and the final membrane shape.

[0050] To solve the technical problem, in some preferred embodiments, step S33 comprises: S331, obtaining structural state information of the current installation stage; S332, adjusting the preset target total stress according to the structural state information to obtain a corrected target total stress; S333, determining the temporary mechanical tension target of the currently selected region according to the additional thermal stress, the tension influence quantity and the corrected target total stress.

[0051] The structural state information of step S331 can be understood as data reflecting the actual physical and mechanical state of the PTFE membrane material and the supporting structure at the current installation time. The structural state information can include the geometric shape of the installed PTFE membrane material and the connection point stress state of the main steel structure member in place. Since the preset target total stress is a designed ideal tension value determined in the design stage, and the structural state information reflects the influence brought by the actual installation environment and progress, step S332 adjusts the preset target total stress according to the structural state information to correct the target total stress, so that the target total stress is more consistent with the current actual structural bearing capacity and deformation condition, thereby avoiding the deviation caused by using the fixed target total stress. Step S333 calculates the temporary mechanical tension target according to the additional thermal stress, the tension influence quantity and the corrected target total stress, so as to ensure that the temporary mechanical tension target is calculated by considering not only the thermal expansion characteristics of the membrane material itself and the tension transmission between regions, but also the actual state in the structural installation process, so that the temporary mechanical tension target is more accurate and safe.

[0052] The scheme of the present application solves the problem that the target total stress is fixed and cannot adapt to the dynamic changes of the structure in the traditional method by introducing the acquisition and utilization of the current installation stage structure state information. It is precisely because the preset target total stress is corrected based on the actual structure state before the temporary mechanical tension target is determined that the finally determined temporary mechanical tension target can more accurately reflect the reasonable tension range that the current structure can withstand. This ensures that not only the temperature changes and the mutual influence between regions are considered in the tensioning process of the PTFE membrane material, but more importantly, the real-time bearing capacity and geometric shape of the structure itself are taken into consideration, thereby avoiding the risk of potential damage to the structure or affecting the final forming quality due to excessive or insufficient tension. Through the above technical scheme, the present application can dynamically adjust the tensioning target according to the actual structure state in the installation process of the PTFE membrane material, thereby significantly improving the accuracy and adaptability of tension control, effectively avoiding the tensioning deficiency or overload problem caused by the fixed target total stress, and effectively ensuring the structural safety of the PTFE membrane material during installation, reducing the construction risk, helping to ensure the geometric precision and aesthetics of the finally formed membrane material, and effectively improving the overall engineering quality.

[0053] In some preferred embodiments, the following is described by a specific example. Assume that a large PTFE membrane structure is being installed in stages. In the early stage of installation, the main steel structure may not have been fully positioned, or some of the connection points have not been fully consolidated, at which time the overall stiffness of the structure is relatively low. In this case, if the tension is still performed according to the preset target total stress in the final design stage, it may cause local stress concentration or excessive deformation of the structure, which poses a safety hazard.

[0054] The scheme of the present application can be implemented as follows: in step S331, the system can obtain the structure state information of the current installation stage, for example, by monitoring the force state of the connection points of the main steel structure members that have been positioned through sensors, or by analyzing the geometric shape of the installed PTFE membrane material (such as whether there are large wrinkles or slack areas) through visual recognition technology. In step S332, the preset target total stress is adjusted according to these structure state information. For example, if it is monitored that the force of some key connection points has reached the design upper limit, or the geometric shape of the membrane material shows that the local stiffness is insufficient, the system can intelligently adjust the preset target total stress of the region or related region to be appropriately lowered to obtain the corrected target total stress; on the contrary, if the structure state is good and has higher bearing potential, the target total stress can be maintained or slightly increased to ensure the final forming effect. In step S333, this corrected target total stress is used, so that the tensioning operation is more in line with the actual bearing capacity and safety requirements of the current structure, avoiding the risks that may be brought by blindly pursuing a fixed target value.

[0055] In some preferred embodiments, the structural state information includes the geometric shape of the installed PTFE membrane and the force state of the connection points of the main steel structural members in place. The geometric shape of the installed PTFE membrane can be understood as the actual spatial shape, curvature variation and possible wrinkle or slack area of the PTFE membrane during the installation process. This shape information can be obtained in real time or quasi-real time by devices such as three-dimensional laser scanners, photogrammetry systems or structural deformation monitoring sensors, to ensure that the actual installation state of the membrane conforms to the design model. The force state of the connection points of the main steel structural members in place refers to the actual mechanical state of the main steel structural members (such as support rods, cables, edge beams, etc.) connected directly or indirectly to the PTFE membrane at these connection points, including axial force, shear force, bending moment, etc. These force states can be continuously monitored by installing high-precision force sensors, strain gauges or through structural health monitoring systems at the connection points, to assess whether the force of the main structure is uniform, whether it exceeds the design bearing range, and whether there are local stress concentrations, etc. The scheme of the present application clearly specifies the specific content of the structural state information, so that the adjustment of the target total stress can more accurately reflect the real stress and deformation of the PTFE membrane and its supporting structure during the actual installation process. Specifically, obtaining the geometric shape of the installed PTFE membrane can real-time grasp the actual spatial position and shape of the membrane, which is crucial for evaluating the pre-tension distribution of the membrane and identifying potential stress concentration areas or slack areas. At the same time, monitoring the force state of the connection points of the main steel structural members in place can ensure that the main structure does not overload or unevenly stressed during the membrane tensioning process, thereby avoiding structural deformation or damage.

[0056] In some preferred embodiments, step S4 comprises: S41, for each region, performing a tensioning operation on the PTFE membrane according to the temporary mechanical tension target, and monitoring the actual total stress of the region in the tensioning operation in real time; S42, analyzing whether the actual total stress reaches the target total stress, if yes, ending, if no, executing step S43; S43, when the deviation between the actual total stress and the target total stress is greater than a preset threshold, adjusting the tension increment corresponding to the tensioning operation to a first tension increment, when the deviation between the actual total stress and the target total stress is less than or equal to the preset threshold and the actual total stress does not reach the target total stress, adjusting the tension increment corresponding to the tensioning operation to a second tension increment, the first tension increment being greater than the second tension increment; S44, performing the adjusted tensioning operation on the PTFE membrane, re-measuring the actual total stress of the region in the tensioning operation, and returning to step S42.

[0057] Step S42 is a preliminary judgment of the tensioning result. If the actual total stress reaches the target total stress, the tensioning operation is stopped. Step S43 is the core of the present scheme, which aims to dynamically adjust the tension increment of the tensioning operation according to the deviation between the actual total stress and the target total stress. A preset threshold is used to distinguish the size of the deviation, which can be set as a certain percentage of the target total stress. When the deviation is large, a larger first tension increment is used to make the actual total stress after the tensioning operation quickly approach the target total stress. When the deviation is small but has not reached the target, a smaller second tension increment is used to avoid overshoot and achieve fine adjustment. The first tension increment and the second tension increment can be pre-set according to the characteristics of the membrane material, the accuracy of the tensioning equipment and engineering experience. Step S44 ensures that the system can continue tensioning according to the adjusted tension increment until the actual total stress reaches the target total stress.

[0058] The scheme of the present application effectively solves the problems of low efficiency and insufficient precision in the traditional tensioning process by introducing a segmented tension increment adjustment strategy. Specifically, when the deviation between the actual total stress and the target total stress is large, a larger first tension increment is used to quickly eliminate most of the deviation, speed up the tensioning process and avoid the extension of the construction period caused by slow small steps. When the deviation is reduced to within the preset threshold, a smaller second tension increment is switched to, which can achieve fine approximation of the target total stress and effectively avoid the overshoot phenomenon caused by excessive tension increment, thereby improving the tensioning precision and stability. This dynamic adjustment mechanism makes the tensioning process both efficient and accurate, and can better adapt to the control requirements under different tension deviation conditions. Through the above technical scheme, the installation and pre-tension control process of the PTFE membrane material can achieve faster convergence speed and higher tensioning precision. The scheme can intelligently adjust the tensioning step according to the deviation between the actual tension and the target tension, thereby ensuring the tensioning efficiency while effectively avoiding overshoot and under-tensioning problems, ensuring that the membrane material can accurately reach the required pre-tension state during installation, and improving the engineering quality and construction efficiency.

[0059] In some preferred embodiments, the following is described by a specific example. Assume that the target total stress of a certain PTFE film area is 100 kPa. During the tensioning process, it is monitored that the actual total stress of the area is 50 kPa, and the deviation is 50 kPa at this time. The preset threshold is set to 10 kPa. Since 50 kPa is greater than 10 kPa, the system judges that the deviation is large, and adjusts the tension increment corresponding to the tensioning operation to the first tension increment, for example, set to 20 kPa. After one tensioning operation, the actual total stress becomes 70 kPa. The deviation is still 30 kPa, and the first tension increment is continued to be used. When the actual total stress reaches 90 kPa, the deviation is 10 kPa, and the deviation is equal to the preset threshold 10 kPa at this time. The system adjusts the tension increment to the second tension increment, for example, set to 2 kPa. The subsequent tensioning operation will be carried out with an increment of 2 kPa until the actual total stress reaches 100 kPa. For example, 90 kPa+2 kPa=92 kPa, 92 kPa+2 kPa=94 kPa, 94 kPa+2 kPa=96 kPa, 96 kPa+2 kPa=98 kPa, 98 kPa+2 kPa=100 kPa. This segmented adjustment strategy makes it fast to approach the target in the early stage and fine adjustment in the later stage, thereby improving the overall tensioning efficiency and accuracy.

[0060] In a second aspect, as shown in Figure 3 The present application also provides a PTFE film installation pre-tension control system, which comprises: A temperature acquisition module 1 for acquiring real-time temperature information of different areas of the PTFE film; A thermal stress acquisition module 2 for acquiring the additional thermal stress of each area according to the film thermal expansion coefficient, the design reference temperature and the real-time temperature information; A tension target confirmation module 3 for determining the temporary mechanical tension target corresponding to each area according to the additional thermal stress and the preset target total stress; A tensioning module 4 for performing tensioning operation on the PTFE film according to the temporary mechanical tension target for each area, and monitoring the actual total stress of the area during the tensioning operation, and adjusting the tensioning operation according to the deviation between the actual total stress and the target total stress until the total stress reaches the target total stress.

[0061] The PTFE membrane installation pre-tension control system provided by the embodiment comprises a temperature acquisition module 1, a thermal stress acquisition module 2, a tension target confirmation module 3 and a tensioning module 4. The PTFE membrane installation pre-tension control system provided by the embodiment is used to execute the steps in the PTFE membrane installation pre-tension control method provided in the first aspect. The principle of the PTFE membrane installation pre-tension control system provided by the embodiment is the same as that of the PTFE membrane installation pre-tension control method provided in the first aspect, and will not be discussed in detail here.

[0062] As can be seen from the above, the PTFE membrane installation pre-tension control method and system provided by the embodiment can realize accurate tensioning operation by acquiring temperature information of different regions of the PTFE membrane in real time, calculating additional thermal stress according to the temperature information, and dynamically adjusting temporary mechanical tension targets of the regions. Therefore, the influence of temperature change on the stress state of the membrane can be effectively eliminated, and the pre-tension target can be adjusted according to the dynamic temperature field, so as to ensure that the finally applied pure mechanical pre-tension can accurately and uniformly meet the design requirements under complex and changeable environmental conditions, thereby effectively improving the construction precision, safety and long-term stability of the PTFE membrane structure.

[0063] In the embodiments provided by the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are only illustrative. For example, the division of the units is only a logical function division. In actual implementation, another division mode can be used. For example, a plurality of units or components can be combined or integrated into another robot, or some features can be omitted or not executed. In addition, the coupling or direct coupling or communication connection between the displayed or discussed entities can be indirect coupling or communication connection through some communication interfaces, devices or units, which can be electrical, mechanical or other forms.

[0064] In addition, the functional modules in each of the embodiments of the present application can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0065] In this document, the relationship terms such as first and second are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0066] The above is only an embodiment of the present application and is not used to limit the protection scope of the present application. For those skilled in the art, the present application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for controlling pre-tension of a PTFE membrane material installation, characterized by, The PTFE membrane installation pre-tension control method comprises the following steps: S1, obtaining real-time temperature information of different regions of the PTFE membrane; S2, for each region, obtaining additional thermal stress of the region according to the thermal expansion coefficient of the membrane, the design reference temperature and the real-time temperature information; S3, determining the corresponding temporary mechanical tension target of each region according to the additional thermal stress and the preset target total stress; S4, for each region, performing a tensioning operation on the PTFE membrane according to the temporary mechanical tension target, and monitoring the actual total stress of the region in the tensioning operation process in real time, and adjusting the tensioning operation according to the deviation between the actual total stress and the target total stress until the total stress reaches the target total stress.

2. The method of claim 1, wherein Step S2 comprises: S21, for each region, applying a preset pre-tension to the PTFE membrane, and locking the mechanical stroke of the tensioning device, wherein the preset pre-tension is less than the target total stress; S22, for each region, collecting the tension change amount and the temperature change amount of the PTFE membrane; S23, for each region, determining the actual thermal expansion coefficient of the PTFE membrane in the region according to the tension change amount and the temperature change amount; S24, for each region, obtaining additional thermal stress of the region according to the actual thermal expansion coefficient, the design reference temperature and the real-time temperature information.

3. The method of claim 2, wherein Step S22 comprises: S221, for each region, obtaining the tension change rate of the PTFE membrane in the region within a preset time window, and obtaining the actual mechanical stroke of the tensioning device; S222, for each region, when the tension change rate is less than a preset stability threshold and the deviation between the actual mechanical stroke and a preset mechanical stroke is less than a preset stroke deviation, collecting the tension change amount and the temperature change amount of the PTFE membrane.

4. The method of claim 2, wherein Step S23 comprises: S231, for each region, in the state that the mechanical stroke of the tensioning device is locked, applying a preset displacement disturbance to the PTFE membrane, and monitoring the tension response of the PTFE membrane to the preset displacement disturbance; S232, for each region, determining the effective stiffness of the PTFE membrane in the region according to the preset displacement disturbance and the tension response, and then determining the actual thermal expansion coefficient of the PTFE membrane in the region according to the tension change amount, the temperature change amount and the effective stiffness.

5. The method of claim 1, wherein Step S3 comprises: S31, selecting any region whose temporary mechanical tension target has not been determined; S32, according to the positions of all tensioned regions and their corresponding actual tension data, the positions of all regions whose temporary mechanical tension targets have been determined and their corresponding temporary mechanical tension targets, the position of the currently selected region and the corresponding preset mechanical transmission characteristics of the PTFE membrane, obtaining the tension influence amount of the regions whose temporary mechanical tension targets have been determined on the currently selected region; S33, determining the corresponding temporary mechanical tension target of the currently selected region according to the additional thermal stress, the tension influence amount and the preset target total stress; S34, repeating steps S31-S33 until all regions have been selected. S34, analyze whether there are still regions without determined temporary mechanical tension targets, if yes, return to step S31, if no, execute step S4.

6. The method of claim 5, wherein Step S32 includes: S321, obtain environmental wind load and temperature distribution information of the PTFE membrane material; S322, correct the preset mechanical transmission characteristics corresponding to the PTFE membrane material according to the environmental wind load and the temperature distribution information to obtain corrected mechanical transmission characteristics; S323, obtain the tension influence amount of the regions with determined temporary mechanical tension targets on the currently selected region according to the positions of all completed tensioning regions and their corresponding actual tension data, the positions of all regions with determined temporary mechanical tension targets and their corresponding temporary mechanical tension targets, the position of the currently selected region and the corrected mechanical transmission characteristics.

7. The method of claim 5, wherein the method further comprises: Step S33 includes: S331, obtain structural state information of the current installation stage; S332, adjust the preset target total stress according to the structural state information to obtain a corrected target total stress; S333, determine the temporary mechanical tension target corresponding to the currently selected region according to the additional thermal stress, the tension influence amount and the corrected target total stress.

8. The method of claim 7, wherein the method further comprises: The structural state information includes the geometric shape of the installed PTFE membrane material and the connection point stress state of the in-place main body steel structure member.

9. The method of claim 1, wherein Step S4 includes: S41, for each of the regions, perform a tensioning operation on the PTFE membrane material according to the temporary mechanical tension target, and monitor the actual total stress of the region in the tensioning operation in real time; S42, analyze whether the actual total stress reaches the target total stress, if yes, end, if no, execute step S43; S43, when the deviation between the actual total stress and the target total stress is greater than a preset threshold, adjust the tension increment corresponding to the tensioning operation to a first tension increment, when the deviation between the actual total stress and the target total stress is less than or equal to the preset threshold and the actual total stress does not reach the target total stress, adjust the tension increment corresponding to the tensioning operation to a second tension increment, the first tension increment being greater than the second tension increment; S44, perform the adjusted tensioning operation on the PTFE membrane material, re-measure the actual total stress of the region in the tensioning operation, and return to step S42.

10. A PTFE membrane installation pre-tension control system, characterized by, The PTFE membrane material installation pre-tension control system includes: A temperature acquisition module for obtaining real-time temperature information of different regions of the PTFE membrane material; A thermal stress acquisition module for obtaining, for each of the regions, an additional thermal stress of the region according to the membrane thermal expansion coefficient, the design reference temperature and the real-time temperature information; A tension target confirmation module for determining the temporary mechanical tension target corresponding to each of the regions according to the additional thermal stress and the preset target total stress; A tension target confirmation module for determining the temporary mechanical tension target corresponding to each of the regions according to the additional thermal stress and the preset target total stress; A tensioning module is configured to, for each of the regions, perform a tensioning operation on the PTFE membrane material according to the temporary mechanical tension target, and monitor an actual total stress of the region in real time during the tensioning operation, and adjust the tensioning operation according to a deviation between the actual total stress and the target total stress until the total stress reaches the target total stress.

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