Development Of Testing Instrument Of Bolt Anchorage

Anchor reinforcement technology is widely used in various construction projects.Whether the anchorage anchor system meets the engineering design requirements and has played an expected anchoring role,it is a big issue related to the safety of life and property.Therefore,the detection of bolt anchorage quality plays an important role in the bolt anchorage project.Testing instrument of bolt anchorage is a non-destructive testing instrument.Traditional testing instruments are mostly bulky and have high power consumption.Two people are required to complete the test.In this paper,a design scheme of a new type of testing instrument of bolt anchorage is proposed.The scheme divides the instrument into two parts,one of which is a data acquisition system for detection;the other part is the upper computer which adopts mobile phone or laptop;the data acquisition system is connected with the upper computer through a bluetooth method to realize the detection of bolt anchorage quality.The instrument has the advantages of small size,convenient carrying,low power consumption,low cost,and can be completed by one person.For the design of the instrument,a voltage-type acceleration sensor was first selected as the vibration sensor of the testing instrument of bolt anchorage,which is a charge-acceleration sensor.In this regard,a low-noise charge amplifier was designed using CMOS operational amplifier OPA350 of TI.In order to adapt to the complex detection environment,a programmable gain amplifier is added,and the gain adjustment range is designed to be 33dB?66dB.Taking into account the range of the analog-to-digital converter,the THS4521 is further used to design the driver amplifier to ensure that the signal output voltage reaches the analog-to-digital converter range of-4.4V to +4.4V.The data acquisition module of the instrument is completed with the ADS1606 analog-to-digital converter,and the controller STM32F407 based on the ARM core is selected as the acquisition and control.The ADS1606 clock is generated by the timer TIM4 of the STM32F407.The data output of the ADS1606 is connected to the FSMC of the STM32F407.In order to reduce the CPU time for data read during data acquisition,the data is read using the combination of interrupt and DMA.The data acquisition system is connected with the upper computer through a bluetooth method,the bluetooth module adopts CC2564,this module supports the SPP specification and can be connected with different types of upper computers.At the same time,a set of data transmission protocols was designed to ensure the reliable transmission of data.In order to detect the performance of the testing instrument of bolt anchorage,a series of performance tests were performed on the instrument,including frequency characteristics,noise characteristics,and stability of the instrument.The test results showed that the system noise of the instrument is less than 50 uV and the 3dB bandwidth is approximately 90Hz?90kHz,reaching the design level.The experimental model was further tested in the laboratory and the test results were in good agreement with the actual situation.