Fiber-optic crack-tip opening displacement sensor for concrete

Document Type

Article

Publication Date

1-1-1997

Abstract

The development of a fiber-optic sensor for embedment in cementitious composites and measurement of displacements associated with the opening of microcracks are described. The sensor can be employed as a transducer for measurement of crack-tip opening displacements during fracture tests. A polarization-maintaining optical fiber is used as the sensing element, and the transduction mechanism is similar to those of other sensors based on polarimetric-type based fibers. However, the deformation resolving power of the sensor is increased by way of increasing the effective length of the optical fiber. This is done by winding the optical fiber into a coil. A direct relationship between the number of loops in the coil and sensitivity of measurements is obtained. A calibration procedure is developed by which the optical signal is converted to displacements. The sensor was employed in a series of fracture tests. Experiments involved embedment of the optical fiber in concrete beams. Specimens were center-edge-notched, and the fiber coil sensors were embedded at the tip of the notch. This arrangement allowed for direct measurement of displacements associated with the opening of microcracks at the crack tip. Experimental results are presented, and crack-tip opening displacement (CTOD) results are compared with crack-opening displacements measured by conventional transducers at the crack mouth (COD). © 1997 Elsevier Science Limited.

Identifier

0031074254 (Scopus)

Publication Title

Cement and Concrete Composites

External Full Text Location

https://doi.org/10.1016/s0958-9465(96)00041-8

ISSN

09589465

First Page

59

Last Page

68

Issue

1 SPEC. ISS.

Volume

19

Fund Ref

National Science Foundation

This document is currently not available here.

Share

COinS