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Non-contact Stress Measurement in Steel Member of PSC Box Bridge Using Raman Spectroscopy

라만 형광 분광법을 이용한 PSC 박스교 인장케이블 응력측정방법 연구

Kim, Jongwoo;Kim, Namgyu
김종우;김남규

  • Received : 2019.01.23
  • Accepted : 2019.02.12
  • Published : 2019.03.01

Abstract

In this paper, a laser-based non-contact load cell is newly developed for measuring forces in prestressed concrete tendons. First, alumina particles have been sprayed onto an empty load cell which has no strain gauges on it, and the layer has been used as a passive stress sensor. Then, the spectral shifts in fluorescence spectroscopy have been measured using a laser-based spectroscopic system under various force levels, and it has been found that the relation of applied force and spectral shift is linear in a lab-scale test. To validate the field applicability of the customized load cell, a full-scale prestressed concrete specimen has been constructed in a yard. During the field test, it was, however, found that the coating surface has irregular stress distribution. Therefore, the location of a probe has to be fixed onto the customized load cell for using the coating layer as a passive stress sensor. So, a prototype customized load cell has been manufactured, which consists of a probe mount on its casing. Then, by performing lab-scale uniaxial compression tests with the prototype load cell, a linear relation between compression stress and spectrum shift at a specific point where laser light had been illuminated has been detected. Thus, it has a high possibility to use the prototype load cell as a force sensor of prestressed concrete tendons.

Keywords

Noncontact Sensing;Load Cell;Laser;Piezospectroscopy

Acknowledgement

Supported by : 국토교통과학기술진흥원