Cable net curtain wall health monitoring system based on cable force measurement

Abstract

The utility model relates to the field of constructional engineering, and particularly discloses a cable net curtain wall health monitoring system based on cable force measurement. According to the utility model, the stay wire type displacement sensor is arranged on all steel cables or a key part steel cable area of the cable net curtain wall structure, two ends of the sensor stay wire and two ends of the steel cable body are respectively arranged at the same point position, and the sensor stay wire passes through the stay wire chute on the glass gripper; when glass on a curtain wall is stressed to drive the glass gripper to transversely move, the glass gripper drives the steel cable body and the sensor stay wire to synchronously deform, and the stay wire type sensor can measure the elongation of the sensor stay wire due to the fact that the sensor stay wire can longitudinally slide and extend in the glass gripper. The elongation of the sensor stay wire is the deformation elongation of the steel cable body, the deformation increased cable force of the steel cable body is calculated according to the material elasticity theory of the steel cable body material, and the total cable force of the steel cable body is the sum of the prestress and the deformation increased cable force at the moment, so that the change condition of the cable force increment is measured.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of building engineering, specifically relates to a cable net curtain wall health monitoring system based on cable force measurement. BACKGROUND

[0002] With the development of modern building industry, people's requirements for the use function, aesthetic effect, use comfort degree and the like of building structure are higher and higher, and a curtain wall structure - prestressed cable cable net curtain wall structure which is beautiful, has good lighting permeability, is green and low carbon emerges as the times require and is more and more widely praised and concerned. The curtain wall structure uses high-strength steel wire which is twisted into high-strength prestressed cable through complex and special process treatment as glass bearing component, and the prestressed cable is applied to the cable net curtain wall structure system as a kind of prestressed cable of cable component because of the characteristics of high strength (1320Mpa~1770Mpa, 4~6 times of the strength of ordinary steel), small volume and beautiful appearance (the steel wire can adopt stainless steel material, and can also use high-vanadium plated carbon steel, in short, the steel wire has strong bare metal feeling), so the cable net curtain wall has distinct flexible structure characteristics, that is, large span, small component (small volume, bending stiffness of cross section is almost 0), strong bearing capacity, and also has the characteristics of large deformation and large structural stiffness affected by cable force.

[0003] Because the cross-sectional stiffness of single cable component is small, the overall stiffness of the structure needs the interaction (also mutual influence) of other cable components and reaches a certain cable force level, so the overall stiffness of the structure is greatly affected by the cable force level of single cable component, which is very obvious in the construction phase and the use phase of the curtain wall structure, that is, the cable force level of the cable component directly determines the working capacity of the cable net curtain wall structure system. For example, if the cable force of the cable component is applied incorrectly in the construction phase or appears local cable force natural relaxation in the use phase, the stiffness of the curtain wall system is redistributed, which will lead to defects such as local cable force being too large or too small, local deformation being too large, and further lead to local glass breakage or more serious loss of the ability of the curtain wall system to continue to be used, in addition, it will also have certain influence on the surrounding main structure.

[0004] In summary, the cable force level of the cable component in the cable net curtain wall structure system is the prerequisite to ensure the normal and effective work of the structure system, so whether in the construction phase or in the use phase, whether the cable force level of each cable can be conveniently and accurately obtained is the key to ensure the engineering quality and safety.

[0005] The monitoring scheme of the existing cable net curtain wall mainly focuses on the method of monitoring the cable force, and comparing with the design cable force. If the difference between the two exceeds the threshold value set in advance, that is, the deviation of the cable force of the curtain wall exceeds the allowed range, it is considered that the cable curtain wall structure is in an "unsafe state". However, it is not easy to conveniently and quickly obtain the cable force of the cable curtain wall in use.

[0006] The current development of the more mature prestressed cable measurement method has oil gauge reading method, frequency method, weighing sensor method, magnetic flux sensor method and embedded optical fiber grating method, oil gauge reading method is through the use of tensioning equipment - jack and oil gauge to read the tensioning end of the prestressed cable tension, building equipment after completion, the tension measurement becomes extremely difficult and costly, in addition, because the method can only measure the tensioning equipment cable end, and can not measure the cable body any part of the cable tension, so the method is only limited to the measurement of the end of the construction process cable tension; Frequency method is a cable force detection method developed by using the physical relationship between the cable force and the cable force in the prestressed cable, but the measurement object of this method is limited to simply supported cable without other interference, if the cable body is connected with other building components, such as other cables, steel beams, struts, etc., the natural frequency of the detected cable itself is distorted due to the "interference" of other components, at this time the method becomes infeasible; Weighing sensor method refers to embedding weighing sensor at the end of prestressed cable, which can transfer the tension of prestressed cable through its structure, so as to measure the tension of prestressed cable. Like oil gauge reading method, this method needs to embed the equipment in the fixed part of the cable, and participate in the cable stress, so it is only limited to the cable tension measurement at the embedded part, which is costly; Magnetic flux method is to use the magnetostriction effect of the detected object - prestressed cable, that is, the stress change of steel cable will lead to the change of magnetic permeability of steel cable, so as to cause the change of external magnetic field physical quantity. By measuring the changed magnetic field physical quantity, the corresponding steel cable stress (tension) is obtained by using the monotonic relationship between steel cable stress and magnetic field physical quantity. This method is only limited to carbon steel cable (stainless steel cable has no magnetic permeability, so it is not applicable), and complex calibration is needed before magnetic flux measurement. The accuracy of measurement depends largely on the calibration data before implementation, which is costly. In addition, the magnetic flux sensor is placed outside the prestressed cable, its outer diameter is generally 50-100mm larger than the diameter of the measured cable body, and the height is generally 200-300mm, which is equivalent to a "iron column" on the steel cable. This "iron column" is not easy to "hide" in the relatively permeable cable curtain wall, which goes against the original intention of the architects to design the cable curtain wall. They use the steel cable curtain wall with 5-10 times higher bearing capacity than ordinary steel parts to reduce the size of the curtain wall structure member, so as to obtain a wide view with almost no obstruction. The embedded optical fiber grating sensor method is to implant one or several optical fiber grating sensors in the cable body in advance, and it is considered that the deformation of optical fiber grating is synchronous with the deformation of prestressed cable (or there is a certain constant mapping relationship), so the cable tension of prestressed cable can be "inferred" through the deformation of optical fiber grating.This method is a new technology developed in recent years, and the scale and range of use are not extensive, especially in cable wall structure, there are few cases. In addition, this method actually implants sensors in the cable body (only the volume of fiber grating sensor is small, and the influence on the stress performance and appearance of the cable body is almost negligible), but it puts forward higher requirements for the twisting, anchor pouring, cable transportation, installation and other links of the cable body.

[0007] Among the above five methods of measuring cable force, the last three are to "integrate" sensors in the measured cable force (hereinafter referred to as "integrated sensor method"), and the cable force in the cable wall is measured by sensors. This "integrated sensor method" has a common disadvantage, that is, the process of maintaining and replacing sensors is extremely complicated, and the cost is quite amazing, which greatly reduces the benefits brought by the health monitoring of cable wall. Taking the magnetic flux sensor method as an example, the following describes the brief process of replacing the sensor: According to the principle and characteristics of the magnetic flux sensor method, the magnetic flux sensor is placed on the measured cable body before the cable body and anchor pouring. Once the anchor pouring is completed, the sensor cannot be completely removed. If you want to remove the sensor, you need to remove the cable end anchor. For the cable net wall in use, to remove the sensor on the measured cable, you need to use the opposite process to the installation process to remove it one by one. The process of removal is roughly as follows: remove the glass → release the cable force → remove the replacement cable body → remove the cable anchor → remove the sensor → pour the cable body and anchor → install the replacement cable body → tension the replacement cable body → install the glass → others. It should be noted that the "removal of cable anchor" and "pouring of cable body and anchor" in the above replacement process need to be carried out in the original factory, and cannot be implemented on site. Therefore, the maintenance and replacement of the sensor of this method are extremely complicated, and the economic benefits are greatly reduced.

[0008] In summary, all the problems in the health monitoring of cable wall are that the cable force of the prestressed steel cable cannot be efficiently and accurately obtained, and the safety evaluation of the cable force of the prestressed steel cable cannot be realized. In the above traditional cable force measurement methods, either real-time automatic measurement is not possible, such as the oil gauge reading method which is limited to manual operation during construction; or the measurement data is not accurate, such as the measurement conditions of the frequency method cannot be met, the accuracy of the data obtained is not enough, and it cannot be used as a basis for evaluation; the last three sensor methods can meet the requirements of cable wall health monitoring in terms of data acquisition method and reliability, but due to the integration of sensors and measured cables, the placement of sensors and the appearance of buildings are greatly affected, and the commercial cost is relatively high. More fatally, the "integrated sensor method" brings great difficulties to the maintenance, repair and replacement of the monitoring system. Therefore, a monitoring system that can efficiently and accurately measure the cable force of the prestressed steel cable needs to be redesigned. Practical new type

[0009] In order to overcome the prior art, the utility model discloses a cable net curtain wall health monitoring system based on cable force measurement to solve the problem that the prior measurement mode cannot accurately and efficiently measure prestressed cable cable force at low cost.

[0010] In order to achieve the above object, the utility model provides the following technical scheme:

[0011] A cable net curtain wall health monitoring system based on cable force measurement, comprising:

[0012] The curtain wall lower frame-cable anchoring point is provided with a steel cable tensioning end anchor at the curtain wall lower frame-cable anchoring point.

[0013] The curtain wall upper frame-cable anchoring point is provided with a steel cable fixed end anchor at the curtain wall upper frame-cable anchoring point, and a steel cable body is fixedly connected between the steel cable fixed end anchor and the steel cable tensioning end anchor.

[0014] The pull-wire type displacement sensor storage box is connected to the steel cable tensioning end anchor.

[0015] The sensor pull-wire head fixed end is provided on the steel cable fixed end anchor.

[0016] Preferably, the sensor pull-wire is parallel to the steel cable body.

[0017] Preferably, the sensor pull-wire is attached to the inner wall of the pull-wire slot and slides along the slot axis of the pull-wire slot.

[0018] Preferably, the displacement measurement accuracy of the pull-wire type displacement sensor is greater than 7 microns.

[0019] Preferably, the pull-wire type displacement sensor is connected to an upper computer, and the upper computer is built-in with an algorithm.

[0020] Compared with the prior art, the utility model has the beneficial effects that:

[0021] The utility model discloses a cable -net curtain wall health monitoring system based on cable force measurement, including: BRIEF DESCRIPTION OF DRAWINGS

[0029]

[0030] It is the system overall structure schematic drawing of the utility model;

[0031] It is the glass grab and sensor cable cooperation structure section view of the utility model;

[0032] In the drawing: 1, the cable -net curtain wall health monitoring system based on cable force measurement, including:

[0033] DETAILED DESCRIPTION

[0034] The technical scheme in the embodiments of the utility model will be described clearly and completely below in conjunction with the drawings in the embodiments of the utility model, and obviously, the described embodiments are only part of the embodiments of the utility model, not all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by the person skilled in the art without creative labor belong to the range of the utility model protection. Figure 2 Embodiment:

[0035] Please refer to

[0036] - As shown in the figure, a cable -net curtain wall health monitoring system based on cable force measurement, including:

[0037] Curtain wall lower frame-cable anchorage point 5, provided in the lower frame of the cable net curtain wall, the lower frame of the cable net curtain wall is fixedly connected with the steel cable tensioning end anchor 6 at the curtain wall lower frame-cable anchorage point 5;

[0029] Curtain wall upper frame-cable anchorage point 10, provided in the upper frame of the cable net curtain wall, the upper frame of the cable net curtain wall is fixedly connected with the steel cable fixed end anchor 9 at the curtain wall upper frame-cable anchorage point 10, the steel cable fixed end anchor 9 and the steel cable tensioning end anchor 6 are fixedly connected with the steel cable body 8, and the steel cable body 8 is fixedly connected with the glass grab 7 for fixing the glass;

[0030] Cable displacement sensor storage box 1 connected to the steel cable tensioning end anchor 6, the cable displacement sensor storage box 1 is connected with the extendable sensor cable 3 at the outlet end, the cable displacement sensor storage box 1 is provided with a cable displacement sensor inside for collecting the stretching length of the sensor cable 3;

[0031] Sensor cable head fixed end 4 provided on the steel cable fixed end anchor 9, the sensor cable 3 penetrates the cable sliding groove 2 on the glass grab 7 and is fixedly connected to the sensor cable head fixed end 4.

[0032] As can be seen from the above, the cable displacement sensor storage box 1 and the cable displacement sensor are arranged on all steel cables or key position steel cable regions of the cable net curtain wall structure, and the two ends of the sensor cable 3 of the cable displacement sensor are arranged at the same point as the two ends of the steel cable body 8, that is, the two ends of the sensor cable 3 can be arranged on the steel cable fixed end anchor 9 and the steel cable tensioning end anchor 6, and the sensor cable 3 passes through the cable sliding groove 2 on the glass grab, when the glass on the curtain wall drives the glass grab 7 to move transversely, the glass grab 7 drives the steel cable body 8 and the sensor cable 3 to deform synchronously, since the sensor cable 3 can slide longitudinally inside the glass grab 7, the cable displacement sensor can measure the elongation of the sensor cable 3 at this time, the elongation of the sensor cable 3 is the deformation elongation of the steel cable body 8, and the deformation increase of the cable force of the steel cable body 8 is calculated according to the material elasticity theory of the steel cable body 8 material, at this time the total cable force of the steel cable body 8 is the prestress plus the deformation increase of the cable force, so as to measure the change of the cable force increment, and further diagnose or evaluate the safety performance of the curtain wall structure, realize the risk identification and safety early warning of the cable net curtain wall structure in the whole life cycle, that is, the health monitoring of the cable net curtain wall, which is convenient for guiding the use, maintenance and repair of the cable net curtain wall structure.

[0033] In order to make the elongation of the sensor cable 3 equal to the elongation of the steel cable body 8, the sensor cable 3 is parallel to the steel cable body 8, at this time the deformation of the sensor cable 3 and the steel cable body 8 is similar, and the elongation of the sensor cable 3 can be equivalent to the elongation of the steel cable body 8.

[0034] Referring to Figure 2 The sensor pull wire 3 is attached to the inner wall of the pull wire slot 2 and slides along the slot axis direction of the pull wire slot 2, that is, the sensor pull wire 3 can only slide axially in the pull wire slot 2 and cannot shake in the pull wire slot 2.

[0035] The displacement measurement accuracy of the pull wire type displacement sensor is greater than 7 microns, and the pull wire type displacement sensor can adopt a high-precision pull wire type displacement sensor disclosed in Chinese Patent No. CN202410715619.4.

[0036] The pull wire type displacement sensor is connected with an upper computer, and the upper computer is built-in with an algorithm, which is used to calculate the elongation of the steel cable body according to the sensor pull wire extension length, and then calculate the cable force of the steel cable body according to the elongation of the steel cable body.

[0037] Taking a cable curtain with a span of 20m as an example, the cross-sectional area of the steel cable is about 134mm 2 The stainless steel cable is used as the steel cable body 8, the elastic modulus of the stainless steel cable is about 130000MPa, the breaking force is about 190kN, and it is assumed that the total elastic elongation of 10 microns is obtained by the pull wire type sensor. According to the material mechanics and the above measurement principle, it is calculated that the change of the cable force of the steel cable body 8 is about 8.7N, and the breaking force of the cable in the whole range is 190kN, and the measurement error is about 0.05‰. Of course, this measurement error is related to the span of the cable net curtain. The larger the span, the greater the overall elongation of the cable under the same tension, and the easier it is to be measured by the pull wire type sensor. Conversely, the measurement accuracy will be reduced. But this level of measurement accuracy has greatly exceeded the measurement accuracy of the "integrated sensor method". The measurement error of a general cable force sensor is between 1% and 5%, or even higher. Therefore, the measurement accuracy of the present application has far exceeded the engineering needs, and it is a high-resolution and high-sensitivity technical solution. The reason is that this overall deformation measurement method accumulates local small deformation for overall measurement, that is, only one measurement error is taken. In addition, with the development of electronic technology, the accuracy and stability of the displacement sensor have been greatly improved. Therefore, the resolution and accuracy of this measurement technology are naturally high, and far exceed the measurement of the force of a single steel cable.

[0038] It should be noted that the overall measurement method is more beneficial to the evaluation of the cable curtain wall structure than the data obtained by the local cable force measurement of the "integrated sensor method", for two reasons. Firstly, the core problem of the safety performance of the cable curtain wall is the rotation ability of the glass, and the strength of the cable member is often placed behind the glass fragmentation problem, because the designer often leaves a larger margin for the cable member when designing the cable bearing capacity. In addition, the strength of the cable member generally does not change greatly with the increase of the service life, so the safety of the cable member itself is high. The glass is different, which is a brittle material, and once its rotation ability does not meet its own needs, it will be fragmented, and the rotation ability of the glass is determined by the overall stiffness of the supporting cable. In short, the safety performance of the glass depends more on the overall stiffness of the cable member, and the local cable force measurement cannot completely cover the overall stiffness of the whole cable, or the expression is not accurate. Secondly, since the external load is transmitted to the edge frame member through the prestressed steel cable, the overall cable force is needed for the safety evaluation of the edge frame of the cable curtain wall, rather than the local cable force of a cable. In short, the "integrated sensor method" is beneficial to the monitoring of the safety of the cable member itself, and the "separated sensor method" used in the utility model is more beneficial to the evaluation of the overall safety performance of the cable curtain wall, and the effect is quite remarkable. Unlike other traditional monitoring schemes that require the monitoring system and the curtain wall system to be installed synchronously, the monitoring system and the curtain wall system are independent of each other, the monitoring system can be installed after the curtain wall system, and the installation process of the monitoring system hardly affects the use of the curtain wall system. This provides conditions for adding a monitoring system to some existing curtain wall systems. The size of the wire storage box 1 of the wire displacement sensor is not more than 100*100*100mm, which is much smaller than the general shape size of the cable anchor, and is placed in the same area as the cable anchor 9 and the cable tensioning anchor 6. It is generally hidden by the decorative surface. The wire diameter of the sensor wire 3 is generally not more than 2mm, and the cable is located behind the glass joint, which does not affect the use effect. The utility model measures the cable force of the whole cable, that is, the overall stiffness of the cable, so it is more accurate to evaluate various aspects.

[0039] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the utility model. In the present specification, the illustrative description of the above terms is not necessarily for the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, different embodiments or examples described in the present specification and the features of different embodiments or examples can be combined and combined by those skilled in the art without contradiction.

[0040] The utility model discloses the embodiment of the drawings, only relate to the structure of the embodiment of the disclosure, other structures can refer to the usual design, under the condition of not conflict, the same embodiment and different embodiments of the utility model can be combined with each other.

Claims

1. A cable net curtain wall health monitoring system based on cable force measurement, characterized in that, The curtain wall lower frame-cable anchoring point (5) is arranged on the lower frame of the cable net curtain wall, and the lower frame of the cable net curtain wall is fixedly connected with the steel cable tensioning end anchor (6) at the curtain wall lower frame-cable anchoring point (5). The curtain wall upper frame-cable anchoring point (10) is arranged on the upper frame of the cable net curtain wall, and the upper frame of the cable net curtain wall is fixedly connected with the steel cable fixed end anchor (9) at the curtain wall upper frame-cable anchoring point (10), the steel cable fixed end anchor (9) and the steel cable tensioning end anchor (6) are fixedly connected with the steel cable body (8), and the steel cable body (8) is fixedly connected with the glass grabbing clamp (7) for fixing the glass. The pull-wire displacement sensor storage box (1) is connected to the steel cable tensioning end anchor (6), the pull-wire displacement sensor storage box (1) is connected with the extendable sensor pull wire (3) at the outlet end, the pull-wire displacement sensor storage box (1) is internally provided with a pull-wire displacement sensor for collecting the stretching length of the sensor pull wire (3). The sensor pull wire head fixed end (4) is arranged on the steel cable fixed end anchor (9), and the sensor pull wire (3) penetrates through the pull wire sliding groove (2) on the glass grabbing clamp (7) and is fixedly connected to the sensor pull wire head fixed end (4). The sensor pull wire (3) is parallel to the steel cable body (8). 2.The cable net curtain wall health monitoring system based on cable force measurement of claim 1, wherein: The sensor pull wire (3) is attached to the inner wall of the pull wire sliding groove (2) and slides along the sliding groove axis direction of the pull wire sliding groove (2). 3.The cable net curtain wall health monitoring system based on cable force measurement of claim 1, wherein: The displacement measurement accuracy of the pull-wire displacement sensor is greater than 7 microns.

4. The cable net curtain wall health monitoring system based on cable force measurement of claim 1, wherein: The pull-wire displacement sensor is connected with an upper computer.

5. The cable net curtain wall health monitoring system based on cable force measurement of claim 4, wherein: ​

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