TWI564557B - Automatic concrete anomaly detection system and method - Google Patents

Description

Automated concrete anomaly detection system and method

The invention relates to an automatic concrete anomaly detecting system and method, in particular to an automatic concrete anomaly detecting system and method which can be placed under the concrete structure and automatically detected by a computer built-in sound card.

According to the domestic civil engineering structure, most of the reinforced concrete is used as the construction material. The structure is mainly composed of the steel frame and the concrete which is surrounded by the concrete in the periphery of the steel bar by the grouting method. Among them, the composition of concrete is quite extensive, basically including cement (including Portland cement, sulfur-resistant cement, etc.), mixing materials such as fine sand and coarse and coarse aggregates, and other materials added as needed (such as fly ash, Strong plasticizers and accelerators, etc.).

Concrete consisting of different materials can produce different functions to provide a variety of specific uses. The confining effect of the steel frame on the concrete can increase the toughness and energy absorption and dissipation ability of the structure, and the core (reinforcement skeleton) still has a converging effect after the outer concrete is peeled off.

However, for a region in the Philippine and Eurasia plate boundary, where the geological movements are frequent, the structure of the building often causes serious or partial damage. These damaged structures are usually unable to visually distinguish the damage. When an earthquake occurs, as long as the tensile stress exceeds the tensile strength of the concrete, the concrete will be cracked. At the beginning, the crack is short and small, and then gradually enlarges and invades the inside of the beam-column section; so that the damage of the concrete building after the earthquake damage And the scope may be in whole or in part of the entire building.

Moreover, in general, the steel frame of the building and the concrete of the outer layer are affected by the environmental climate. Because of the heat expansion and contraction or the occurrence of a void layer or crack after the slight earthquake, the external air enters the concrete and even penetrates into the steel skeleton. At the beginning, the corrosion of the steel skeleton is slowly damaged. This is the beginning of the damage point of the whole building. When a larger earthquake occurs, a larger disaster will be formed. Therefore, the timely detection and discovery of the internal structural damage of concrete has become additional importance.

In recent years, the method of detecting the internal structure of concrete is damaged. In recent years, the American Society for Testing and Materials (ASTM) researched the knocking echo method and proposed the standard method of P wave velocity and thickness of concrete slab structure. Judging method replaces the more expensive and time-consuming core sampling method. The tapping echo method belongs to a non-destructive testing (NDT). Non-destructive testing will not cause damage to the building during the speculation, and the detection will not affect its normal use (online detection). It has high mobility and convenience, and is acceptable to most people. It is a way to quickly assess whether the interior of the structure is degraded and deteriorated in a short time. The method of detecting the internal flaws of concrete by the non-destructive detection of the low-frequency transient stress wave transmission principle by the tapping echo method. In the early stage of development, it was mainly used to detect internal defects of slab-like concrete structures (such as retaining walls, beams, columns, tunnel sidewalls, etc.), including reinforced concrete slab internal voids and cracks, honeycomb concrete, and asphalt concrete internal faults. And pores, etc. At present, the application of tapping echo method tends to be diversified, including the detection of internal voids, cracks and honeycombs of rod-shaped structures (beams and columns), the detection of internal defects of tunnel concrete lining structures, the quality inspection of concrete structures, and the minimum detection of cracks in concrete structures. Determination of width and crack depth.

The tapping echo method can perform the detecting work without damaging the concrete structure. However, it is necessary for the measuring personnel to operate the tapping device on site to perform the detecting action, which has the limitation of manpower requirement and the detection efficiency is limited. Not only that, if the concrete structure to be measured is located in a poor foothold such as a pier or a dam, it is not only inconvenient for the person carrying the measuring device, but the probability of accidental occurrence is also greatly increased. Moreover, the current methods for analyzing non-destructive detection signals are mostly complicated methods such as signal processing using a picker, which is not only time consuming but also complicated.

Therefore, how to provide an efficient, safe and automated concrete anomaly detection system and method has been a hard work for researchers and related manufacturers in this industry.

The purpose of the present invention is to provide an automated concrete anomaly detection system and method, which can improve the manpower requirement and the detection efficiency of the concrete detection in the prior art, and can automatically set the structure beside the concrete structure and return the data. Quick analysis.

In order to achieve the above objectives, the present invention is achieved by the following technical means, wherein the automatic concrete anomaly detection system of the present invention comprises: an automatic tapper disposed beside a concrete structure for automatically tapping the concrete And an arithmetic device electrically coupled to the automatic tapper; wherein the automatic tapper strikes the concrete structure and generates one of the data, the automatic tapper collects the data and transmits the data to the An arithmetic device that converts the data into a digital signal by using a sound card, and the computing device analyzes the digital signal by using fast Fourier transform.

In a preferred embodiment of the present invention, the automatic tapper includes at least: a motor; a tapping rod connected to the motor through a connecting member; a sound receiving unit; and a control unit electrically connected to the motor; A transmission unit is electrically connected to the control unit and the sound pickup unit.

In a preferred embodiment of the present invention, the computing device includes at least: a receiving unit; a sound card electrically connected to the receiving unit; and an arithmetic unit electrically connected to the sound card for calculating the digital signal The wave velocity, the thickness of the concrete structure, and the analysis of the internal enthalpy of the concrete structure.

In a preferred embodiment of the present invention, the autopilot transmits the data to the computing device over a wireless network.

In the preferred embodiment of the present invention, the data is an echo.

In a preferred embodiment of the present invention, the automatic tapper automatically strikes the concrete structure after an interval of time to generate the data.

In addition, the present invention further includes an automated concrete anomaly detection method, comprising at least the following steps: (a) providing a concrete structure, an automatic tapper, and an arithmetic device, and the automatic tapper is disposed beside the concrete structure, An automatic tap is electrically connected to the computing device, the computing device has a sound card; (b) the automatic tapper strikes the concrete structure, and the automatic tapper is set to automatically tap the concrete after an interval of time (c) collecting the data generated by the automatic tapping device striking the concrete structure and transmitting the data to the computing device via the wireless network; (d) converting the data into a digital signal by using the sound card; And (e) analyzing the digital signal using fast Fourier transform.

Since the present invention adopts the above technical solutions, the following technical effects can be brought about: (1) The creation uses an automatic tapper to replace the manpower and reduce the cost. (2) This creation replaces the signal extractor with a simple sound card. (3) This creation uses wireless transmission technology to transmit data to the computing device for calculation and analysis.

In order to achieve the above objectives and effects, the technical means and structure adopted by this creation are described in detail in the preferred embodiment of the present creation. The features and functions are as follows, and the full understanding is made, but it should be noted that the contents are not It constitutes a limitation of the present invention.

Please refer to FIG. 1 , which is a schematic diagram of a system architecture of an embodiment of an automated concrete anomaly detection system. The automatic concrete anomaly detection system of the present invention comprises: an automatic tapper 1 and an arithmetic device 2.

Please also refer to FIG. 2, which is a schematic diagram of the structure of the automatic tapper of an embodiment of the automatic concrete anomaly detection system. The automatic tapper 1 is placed beside a concrete structure 3 for automatically tapping the concrete structure 3. The automatic tapper 1 includes a motor 11, a tapping rod 12, a sound pickup unit 13, a control unit 14, and a transmission unit 15.

The striking rod 12 is a rod-shaped metal that is connectable to the motor 11 through a connecting member 16. It is worth mentioning that, due to the metal material striking the concrete structure, it is easy to generate excessive echo noise, which is not easy to analyze. Therefore, a tapping head of wood material is arranged on the front end of the tapping rod 12 to improve the precision of the signal. The sounding unit 13 can select a low impedance, low noise, and high sensitivity microphone. Preferably, in order to make the signal more accurate, the sounding unit 13 can be as close as possible to the tapping rod 12, and the tapping rod 12 can be tapped. The distance between the concrete structures 3 should not exceed 5 cm. The control unit 14 is electrically connected to the motor 11, and can be a circuit board. The circuit design of the control unit 14 can be started at a time to generate a continuous signal output to control the forward and reverse rotation of the motor 11 to reach Automatic tapping effect. The transmission unit 15 is electrically connected to the radio unit 13 and the control unit 14. The transmission mode of the transmission unit 15 is transmitted through a wireless network such as 3G, LTE, WIFI, GPRS, etc., or a combination thereof.

The computing device 2 includes a receiving unit 21, a sound card 22, and an arithmetic unit 23. The receiving unit 21 is connected to the transmission unit 15 via a wireless network. The sound card 22 is electrically connected to the receiving unit 21 and the computing unit 23, respectively. In an embodiment of the present invention, the computing device 2 is a computer, and the creation uses a sound card 22 included in the computer instead of the signal extractor to simplify complicated steps in signal acquisition and analysis, and achieve cost reduction. The effect.

With the above structure and composition design, the following is the use and operation of this creation:

The automatic tapper 1 is disposed adjacent to a concrete structure 3, and the control unit 14 can be set to automatically activate the automatic tapper 1 operation after a time interval. After the automatic tapper 1 is started, the motor 11 drives the tapper to strike the concrete structure 3 to generate a stress wave, and the sound collecting unit 13 collects one of the data 41 generated by the stress wave transmission to the bottom of the concrete structure 3, The data 41 can be an echo and transmitted to the computing device 2 via the wireless network via the transmission unit 15.

The computing device 2 receives the data 41 by using the receiving unit 21, converts the data 41 into a digital signal 42 through the sound card 22, and amplifies the digital signal 42 to facilitate analysis. The arithmetic unit 23 calculates and analyzes the digital signal 42, calculates the wave speed of the digital signal 42, the thickness of the concrete structure 3, and analyzes the internal flaw of the concrete structure 3.

The wave speed of the digital signal 42 is calculated as the first time point when the hammer hits the concrete structure 3, and the sound receiving unit 13 receives the signal as the second time point, and the wave speed can be expressed as in the formula (1). Show: (1) Among them, For the first time, For the second time, The distance between the hit point and the radio point.

The formula for calculating the thickness of the concrete structure can be expressed as shown in formula (2): (2) where T is the thickness of the concrete structure and f is the frequency.

The operation unit 23 converts the digital signal 42 into a series of continuous sine wave superpositions of different frequencies by fast Fourier transform (FFT) to analyze the frequency position and frequency distribution of the digital signal 42. In terms of engineering applications, the fast Fourier transform (FFT) method is used to observe the energy distribution on the spectrum. The purpose is to avoid the external frequency from resonating with the natural frequency of the structure itself, and then to know the crack formation of the structure.

Please also refer to Figures 3 to 6 at the same time. Figure 3 is the waveform of the detection time of the normal concrete structure of the automatic concrete anomaly detection system. Figure 4 is the waveform of the detection frequency of the normal concrete structure of the automatic concrete anomaly detection system. For the detection time waveform of the abnormal concrete structure of the automatic concrete anomaly detection system of the creation, Fig. 6 is the waveform of the detection frequency of the abnormal concrete structure of the automatic concrete anomaly detection system. The arithmetic device 2 analyzes the digital signal 42 to obtain a time waveform diagram of the signal, and then obtains a frequency waveform diagram through fast Fourier transform, and calculates the wave velocity and the thickness of the concrete structure 3 according to the formulas 1 and 2.

By comparing Figures 4 and 6, it can be clearly seen that most of the significant amplitudes of Figure 4 are concentrated at low frequencies, which means that there are fewer surface reflection signals, and no significant amplitude reflection signals only show a distinct main peak, and it is known that the interior of the concrete is extremely uniform, and Innocent reaction. In Fig. 6, in addition to the main peak, there is a distinct sub-peak, which can be known from the enthalpy reaction, and the depth position of the concrete structure can be calculated by the formulas 1 and 2.

Please also refer to Figure 7, which is a flow chart of the artificial concrete anomaly detection method. The creation also includes an automated concrete anomaly detection method that includes the following steps:

Step (a): providing a concrete structure, an automatic tapper, and an arithmetic device, and the automatic tapper is disposed beside the concrete structure, the automatic tapper is electrically connected to the computing device, and the computing device has a Sound Card.

Step (b): The automatic tapper strikes the concrete structure.

Step (c): collecting one of the data generated by the automatic tapper striking the concrete structure.

Step (d): converting the data into a digital signal by using the sound card.

Step (e): analyzing the digital signal by using fast Fourier transform.

In an embodiment of the present invention, the step (b) further comprises: setting the automatic tap to automatically tap the concrete structure after an interval of time.

In an embodiment of the present invention, the step (c) further comprises: transmitting the data to the computing device via a wireless network.

In an embodiment of the present invention, the step (e) further comprises: calculating the digital signal wave velocity, the thickness of the concrete structure, and analyzing the internal flaw of the concrete structure.

In summary, the automatic concrete anomaly detection system and method proposed by the present invention has the following advantages compared with the conventional technology: (1) This creation uses an automatic tapper to replace manpower and reduce costs. (2) This creation can regularly detect the concrete structure to achieve immediate monitoring and prevention. (3) This creation replaces the signal extractor with a simple sound card. (4) This creation uses wireless transmission technology to transmit data to the computing device for calculation and analysis.

The above is only a preferred embodiment of the present invention, and is not intended to limit the scope of the embodiments and the scope of the present invention, and those skilled in the art should be able to Alternatives and obvious variations are intended to be included within the scope of the invention.

1 automatic tapper 11 motor 12 tapping rod 13 sound pickup unit 14 control unit 15 transmission unit 16 connector 2 arithmetic device 21 receiving unit 22 sound card 23 arithmetic unit 3 concrete structure 41 data 42 digital signal step (a): provide a Concrete structure, an automatic tapper and an arithmetic device step (b): the automatic tapper tapping the concrete structure step (c): collecting the automatic tapper to strike the concrete structure to generate one of the data steps (d) ): using the sound card to convert the data into a digital signal step (e): analyzing the digital signal by using fast Fourier transform

FIG. 1 is a schematic diagram of a system architecture of an embodiment of an automated concrete anomaly detection system. FIG. 2 is a schematic structural view of an automatic tapper according to an embodiment of the present invention. Fig. 3 is a waveform diagram showing the detection time of a normal concrete structure according to an embodiment of the automatic concrete anomaly detecting system of the present invention. Fig. 4 is a waveform diagram showing the detection frequency of a normal concrete structure according to an embodiment of the automatic concrete anomaly detecting system of the present invention. Fig. 5 is a waveform diagram showing the detection time of an abnormal concrete structure according to an embodiment of the automatic concrete anomaly detecting system of the present invention. Fig. 6 is a waveform diagram showing the detection frequency of an abnormal concrete structure according to an embodiment of the automatic concrete anomaly detecting system. Figure 7 is a flow chart of the artificial concrete anomaly detection method.

1 automatic tapper 2 arithmetic device 21 receiving unit 22 sound card 23 arithmetic unit 3 concrete structure 41 data

Claims (10)

An automated concrete anomaly detection system comprising: an automatic tapper disposed adjacent to a concrete structure for automatically tapping the concrete structure to generate a stress wave; and an arithmetic device coupled to the automatic tapper telecommunications Connecting; wherein the automatic tapper strikes the concrete structure and generates a data generated by the stress wave being transmitted to the bottom of the concrete structure, the data generating formula is C _p =d/(t ₂ -t ₁ ), T=C _p /2f, where t ₁ is the first time point (the tap hits the concrete structure), t ₂ is the second time point (the concrete structure returns the receiving time point), d The distance between the hitting point and the collecting point, C _p is the wave speed, T is the thickness of the concrete structure, f is the frequency, the automatic tapper collects the data and transmits the data to the computing device, and the computing device utilizes a sound card The data is converted into a digital signal, and the computing device analyzes the digital signal using fast Fourier transform. The automatic concrete anomaly detection system of claim 1, wherein the automatic percussion device comprises at least: a motor; a tapping rod connected to the motor through a connecting member; a sound receiving unit; and a control unit And electrically connected to the motor; and a transmission unit electrically connected to the control unit and the sound pickup unit. The automated concrete anomaly detection system of claim 1, wherein the computing device comprises at least: a receiving unit; An audio card is electrically connected to the receiving unit; and an arithmetic unit is electrically connected to the sound card for calculating the digital signal wave velocity, the thickness of the concrete structure, and analyzing the internal flaw of the concrete structure. The automated concrete anomaly detection system of claim 1 or 2 or 3, wherein the autopilot transmits the data to the computing device via a wireless network. The automated concrete anomaly detection system of claim 1 or 2 or 3, wherein the data is an echo. The automated concrete anomaly detection system of claim 1 or 2 or 3, wherein the automatic tapper automatically strikes the concrete structure after an interval to generate the data. An automated concrete anomaly detecting method includes at least the following steps: (a) providing a concrete structure, an automatic tapper, and an arithmetic device, and the automatic tapper is disposed beside the concrete structure, the automatic tapper and the An arithmetic device telecommunications connection, the computing device having a sound card; (b) the automatic tapper tapping the concrete structure to generate a stress wave; (c) collecting the data generated by the automatic tapper striking the concrete structure, The data is generated by the stress wave being transmitted to the bottom of the concrete structure, and the data is generated by C _p =d/(t ₂ -t ₁ ), T=C _p /2f, where t ₁ is the first time point ( The tapper strikes the concrete structure), t ₂ is the second time point (the concrete structure returns the receiving time point), d is the distance between the tapping point and the collecting point, C _p is the wave speed, and T is the thickness of the concrete structure , f is the frequency; (d) converting the data into a digital signal by using the sound card; and (e) analyzing the digital signal by using fast Fourier transform. The automatic concrete anomaly detection method of claim 7, wherein the step (b) further comprises: setting the automatic tap to automatically tap the concrete structure after an interval of time. The automated concrete anomaly detection method of claim 7, wherein the step (c) further comprises: transmitting the data to the computing device via a wireless network. The automatic concrete anomaly detecting method according to claim 7 or 8 or 9, wherein the step (e) further comprises: calculating the digital signal wave velocity, the thickness of the concrete structure, and analyzing the internal flaw of the concrete structure.