Piezoelectric tension monitoring device

Abstract

The invention discloses a piezoelectric tension monitoring device. A clamping sheet is arranged outside one tested stranded wire or each of 3-5 tested stranded wires, wherein an anchor ring is arranged outside the clamping sheet, a ring is arranged outside the anchor ring, at least two piezoelectric sensors dividing a circumference in equal parts are arranged between the ring and the outer surface of the anchor ring, the piezoelectric sensors are connected with a computer through data wires, and convert the received pressure born by the stranded wire and the pressure born by the stranded wire due to the deformation of the anchor ring through the clamping sheet to electric signals to output to the computer, and the computer computes according to the program set in advance to calculate the tension of the stranded wire. The device disclosed by the invention has the advantages of good stability, high measurement precision, and capability of repeated use, and can be applied to monitoring the tension of the stranded wire when constructing a pre-stressed concrete structure project.

Description

technical field [0001] The invention belongs to the technical field of force measuring equipment or devices, and in particular relates to a testing instrument for an anchorage steel strand assembly. Background technique [0002] At present, prestressing technology is widely used in civil engineering. In the construction of prestressed concrete structures, most of them adopt the post-tensioning method: that is, the component concrete is poured first, and holes are reserved or casings are buried in it. After the concrete reaches the required strength, at least one or more steel strands are inserted into the reserved tunnel, supported on the end of the concrete component by a jack, and the steel strand is stretched, so that the component is simultaneously compressed by the counter force, and the tension is maintained. To control the tension, the size of the control tension is indirectly measured by the oil pressure gauge on the tensioning equipment, that is, the steel strand is...

AI Technical Summary

Problems solved by technology

Due to factors such as the slippage of the prestressed tendons, the shrinkage of the prestressed tendon, and the friction loss of the anchor mouth during the anchoring process of the YJM anchorage, there is obviously an error in the value of the control tension. If the error is too large, the prestress of the component will be less than the design value. Thus leaving engineering hidden dangers (accidents with small pre-compression stress values ​​often occur in engineering construction, resulting in small pre-camber of girders, cracking of components in severe cases, etc.)

In order to ensure the quality of the project, accurately obtain the size of the anchoring force, and reasonably estimate the anchoring force loss value of the YJM anchorage during the anchoring process due to the slippage, shrinkage of the prestressed tendon, and the friction loss of the anchor mouth. A pressure sensor is installed between the anchor plate and the anchor to accurately measure the anchoring force value, but this method can only be used for research and cannot be widely promoted in engineering, because first, the pressure sensor will occupy space, which will change the structural geometry Size design; second, the pressure sensor cannot be reused, thus increasing the project cost, because each pressure sensor ranges from several hundred yuan to several thousand yuan

Images