CN103424082B - A kind of contactless reinforcing bar deformation measuring device and measuring method - Google Patents

Abstract

The invention discloses a kind of contactless reinforcing bar deformation measuring device and measuring method, the stretched condition of two imageing sensor captured in real-time reinforcing bars based on charge-coupled image sensor and by pulling force size synchronous driving to computer, the measured value of each device of computer real time record, the calculating in real time of the software of designed, designed processes, and obtains the tensile elongation of reinforcing bar and the reinforcing bar length situation of change with pulling force.Present configuration is simple, it is possible to achieve non-cpntact measurement reinforcing bar deformation, and certainty of measurement is high, and scope is wide, easy-to-operate, saves manpower, has the prospect that is widely applied very much.

Description

A non-contact steel bar deformation measuring device and measuring method

technical field

The invention relates to the detection and measurement technology of steel bars, in particular to a non-contact steel bar deformation measurement device and measurement method based on double charge coupled devices.

Background technique

With the development of my country's economic construction and the improvement of people's living standards, the inspection of existing buildings has gradually been put on the agenda. Whether there are defects in survey, design, construction, use, etc. of existing buildings, or they are affected by the weather Structural aging caused by chemical corrosion and chemical erosion will bring engineering hidden dangers and reduce the safety and durability of the structure. In order to determine whether the safety and durability of the structure meet the requirements, it is necessary to inspect and appraise the engineering structure, make a scientific evaluation of its reliability, and then carry out maintenance and reinforcement to improve the safety of the engineering structure and prolong its service life. For the reinforced materials used in most buildings now, one of the important testing items is the testing of the mechanical properties of steel bars. Sampling test method is often used to test the actual strength of steel bars. Cut steel bar samples from the site and send them to the laboratory for tensile tests to measure the ultimate tensile strength, yield strength and elongation of the steel bars. The traditional measurement method (document "Hu Shuyang, Zhao Qida, He Shiya, Liao Bangquan. Metal tube packaged fiber grating used in the measurement of building steel strain [J]. Optoelectronics. Laser, 2004,15(6):688-690") is Use the displacement sensor connected to the fixture of the testing machine to measure the overall deformation of the steel bar. This method is easy to damage the sensor because the sensor is in direct contact with the stretched steel bar, and the operation is dangerous. Moreover, it is greatly affected by human factors and has low accuracy. , the degree of automation is low, and in addition, the fixture and the steel bar are prone to slippage during the stretching process, and the measured overall stretching length also has deviations.

Contents of the invention

Aiming at the above-mentioned prior art, the technical problem to be solved by the present invention is: the existing measuring method is easy to destroy the sensor because the sensor is directly in contact with the stretched steel bar, the operation is dangerous, and it is greatly affected by human factors, and the accuracy is not high. The degree of automation is low. In addition, the fixture and the steel bar tend to slip during the stretching process, and the measured overall stretching length also has deviations.

In order to solve the above technical problems, the object of the present invention is to provide a measuring device with safe and convenient operation, simple and effective, high precision, large measuring range and wide application range. The present invention adopts the following technical solutions:

A non-contact steel bar deformation measuring device, characterized in that it includes a first light screen, a second light screen, a first charge-coupled device, a second charge-coupled device, a first acquisition card, a second acquisition card, and a pressure The tension device, light source and computer of the sensor, the first charge-coupled device is facing the first light screen, and the second charge-coupled device is facing the second light screen; the first charge-coupled device and the second charge-coupled device are respectively located At both ends of the steel bar, the first acquisition card is connected to the first charge-coupled device, the second acquisition card is connected to the second charge-coupled device, the steel bar to be measured is stretched by the tension device, and the tension is collected by the pressure sensor It is transmitted to the computer, and the tensile deformation is transmitted to the computer after being collected by the first acquisition card and the second acquisition card.

The measurement system adopts a transmission measurement method, and the light source adopts a parallel light source, which is placed in front of the first light screen, the second light screen, the first charge-coupled device and the second charge-coupled device, and the light bypasses the first light screen and the second light screen, into the first CCD and the second CCD.

Utilize the measuring method of above-mentioned non-contact steel bar deformation measuring device, it is characterized in that, it comprises the following steps:

①The pressure sensor is connected to the tension device, and the computer is connected to the pressure sensor, the first acquisition card and the second acquisition card;

②The first light screen is fixed on the left end of the steel bar. The first light screen moves with the stretching of the steel bar. The first charge-coupled device does not touch the steel bar. The position of the first light screen is dynamically collected by digital photography. The acquisition card acquires the displacement information obtained by the first charge-coupled device;

③The second light screen is fixed on the right end of the steel bar. The second light screen moves with the stretching of the steel bar. The second charge-coupled device does not touch the steel bar. The position of the second screen is dynamically collected by digital photography. The second acquisition The card collects the displacement information obtained by the second charge-coupled device;

④ Subtract the two displacements to obtain the relative displacement deviation, that is, the stretching amount of the steel bar.

Compared with the prior art, the beneficial effects of the present invention are as follows:

1. Non-contact, no need to install measuring scales or sensors on the measured object, only need to operate on the computer, automatic, high efficiency, less manual intervention;

2. What needs to be measured is the deformation of the steel bar per unit length, and during the stretching process, the overall displacement of the steel bar of the measured unit length will occur. The present invention uses two charge-coupled devices to correspond to the initial point of the unit length before and after the stretching of the steel bar respectively. And the end point, two different positions are measured at the same time, the measurement result is more accurate than a single charge-coupled device, and the measurement range is wider;

3. The measurement and experiment results can be integrated by software control and calculation;

4. Digitalization, which can save and print the measurement results on site to prevent fraud, and it can also establish a database for query;

5. Using a non-contact steel bar deformation measurement system controlled by a computer, users only need to perform simple operations on the computer to obtain more accurate measurement results than manual contact measurement.

Description of drawings

Fig. 1 is the overall structural representation of device of the present invention;

Fig. 2 is a graph showing the relationship between the tension change and the steel bar deformation obtained by the device of the present invention through automatic testing.

detailed description

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

A non-contact steel bar deformation measuring device and measuring method, comprising the following steps:

①Connect the pressure sensor to the tension device, and the computer is connected to the pressure sensor, the first acquisition card and the second acquisition card at the same time;

②The first light screen is fixed on the left end of the steel bar. The first light screen is displaced with the stretching of the steel bar. The first charge-coupled device does not touch the steel bar. The position of the first light screen is dynamically collected by photography. The card collects the displacement information obtained by the first charge-coupled device;

③The second light screen is fixed on the right end of the steel bar, and the second light screen is displaced with the stretching of the steel bar. The second charge-coupled device does not touch the steel bar, and the position of the second screen is dynamically collected by photography. The second acquisition card collecting displacement information obtained by the second charge-coupled device;

④ Subtract the two displacements to obtain the relative displacement deviation, which is the stretching amount of the steel bar.

As shown in Figure 1, after the system is connected, start the computer and software, adjust the first charge-coupled device, the second charge-coupled device and other parts to ensure the normal operation of the system. The pulling force device transmits the pulling force data to the computer on which the data acquisition software has been installed and records, while the first charge-coupled device and the second charge-coupled device dynamically record and shoot the positions of the first light screen and the second light screen, the first acquisition card and The second collection card respectively collects the image information acquired by them in real time and transmits the data to the computer through the communication interface for recording. In order to ensure the correspondence between the collected steel bar deformation data and tensile data, the computer must collect data from different devices at the same time, record them simultaneously, and draw real-time curves.

Operation on the designed computer software can obtain the deformation of the steel bar, the relationship between the deformation of the steel bar and the tensile force. The computer software can record the tensile length of the steel bar in real time. The data of the coupler and the pressure sensor can draw the relationship curve between the tensile force and the deformation of the steel bar in real time, save the image and data, and establish a database, which can realize the query and print function.

The data acquisition software is developed with Visual C++ programming language. The specific code can be written according to the communication protocol of each instrument. It can realize the interactive user operation interface, the measurement curve screen drawing, the measurement curve output to the printer for printing, and the management and query of measurement data. The software can be further developed as required. Fig. 2 is a diagram of the relationship between the tension change and the steel bar deformation obtained by the device through automatic testing.

Claims (1)

1. A method for measuring steel bar deformation with a non-contact steel bar deformation measuring device. The non-contact steel bar deformation measuring device includes a first light screen, a second light screen, a first charge-coupled device, a second charge-coupled device, and a first acquisition card , a second acquisition card, a tension device connected with a pressure sensor, a light source, and a computer, the first charge-coupled device is facing the first light screen, and the second charge-coupled device is facing the second light screen; the measurement system adopts a transmissive measurement way, the light source is a parallel light source, which is placed in front of the first light screen, the second light screen, the first charge-coupled device and the second charge-coupled device, and the light bypasses the first light screen and the second light screen, Enter first charge coupled device and second charge coupled device; The card is connected to the second charge-coupled device, the steel bar to be measured is stretched by the tension device, the tension is collected by the pressure sensor and then transmitted to the computer, and the tensile deformation is transmitted to the computer after being collected by the first acquisition card and the second acquisition card , the computer collects the data from the tension device, the first acquisition card and the second acquisition card simultaneously, and records and draws a real-time curve, it is characterized in that, comprising the following steps: ①The pressure sensor is connected to the tension device, and the computer is connected to the pressure sensor, the first acquisition card and the second acquisition card; ②The first light screen is fixed on the left end of the steel bar. The first light screen moves with the stretching of the steel bar. The first charge-coupled device does not touch the steel bar. The position of the first light screen is dynamically collected by digital photography. The acquisition card acquires the displacement information obtained by the first charge-coupled device; ③The second light screen is fixed on the right end of the steel bar. The second light screen moves with the stretching of the steel bar. The second charge-coupled device does not touch the steel bar. The position of the second screen is dynamically collected by digital photography. The second acquisition The card collects the displacement information obtained by the second charge-coupled device; ④ Subtract the two displacements to obtain the relative displacement deviation, that is, the stretching amount of the steel bar; ⑤Using the pressure sensor data and the stretching amount of the steel bar, the relationship curve between the tensile force and the deformation of the steel bar is drawn in real time.