Novel three dimensional stress measuring sensor

Abstract

The invention relates to a novel three dimensional stress measuring sensor, which comprises a machine body and hardware circuits, wherein the machine body is composed of a metal hollow elastic body and resistance strain gages, and is buried in bituminous concrete, the resistance strain gages are in three groups, the three groups are used for measuring the component of the applied stress in X, Y, and Z directions respectively, each group has four resistance strain gages, and when stress is applied on the metal hollow elastic body, two resistance strain gages are pulled and two are pressed in each group, and strain symbols are opposite; the hardware circuits comprise differential type Wheatstone full bridge circuits, zero setting circuits, an amplifying circuit, an acquisition module, a digital filtering module, a communicating module, and a power supply circuit; the three groups of the strain gages make up the three differential type Wheatstone full bridge circuits respectively, and each differential type Wheatstone full bridge circuit is in external connection with a zero setting circuit; outputs of the three groups of the each differential type wheatstone full bridge circuits are communicated with a PC machine through the amplifying circuit, the acquisition module, the digital filtering module, the communication module.

Description

technical field [0001] The invention relates to a sensor and detection technology, in particular to a sensor for detecting internal stress of road surface in road engineering. Background technique [0002] In the past, most of the research on asphalt pavement stayed at the level of material testing, but there were not many studies on its structural performance, especially on the internal mechanics theory of asphalt concrete pavement structure, and the existing research only stayed at the level of theoretical analysis. There are very few studies on pavement structure tests relying on sensors. Most of the pressure sensors in the existing research realize the single-dimensional sensing function. However, in order to accurately analyze the stress inside the asphalt pavement, the sensor must have multi-dimensional sensing capabilities, at least It is to accurately measure the stress in the three directions of x, y and z. [0003] The existing equipment for internal stress detect...

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Problems solved by technology

[0002] In the past, most of the research on asphalt pavement stayed at the level of material testing, but there were not many studies on its structural performance, especially on the internal mechanics theory of asphalt concrete pavement structure, and the existing research only stayed at the level of theoretical analysis. There are very few studies on pavement structure tests relying on sensors. Most of the pressure sensors in the existing research realize the single-dimensional sensing function. However, in order to accurately analyze the stress inside the asphalt pavement, the sensor must have multi-dimensional sensing capabilities, at least It is to accurately measure the stress in the three directions of x, y and z

[0003] The existing equipment for internal stress detection of asphalt pavement in the road industry includes fiber grating stress sensors, ultrasonic sensors, cement-based piezoelectric sensors and resistance strain gauge sensors, but fiber grating stress sensors and ultrasonic sensors are used in actual civil engineering structure detection at home and abroad. The research has just started, and there are still some problems that need to be solved in many aspects, such as high cost, poor compatibility, easy to be disturbed by the external environment, etc., and the one-time investment of testing equipment is relatively large, which greatly restricts its promotion speed

Cement-based piezoelectric sensors can only measure dynamic stress, and the laws and mechanisms of many factors affecting the performance of cement-based composites are not particularly clear, and further research is needed

Existing resistance strain gauge sensors, such as 'I'-shaped asphalt concrete strain sensors, are too large in size, and can better realize their measurement functions when used to measure actual roads with large volumes, and the sensor can only measure asphalt Stress in the horizontal direction inside the concrete

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