Experimental comparative testing of steel structures by strain gauges, Digital Image Correlation and magnetic field methods

摘要

Monitoring of civil engineering structures is an important issue due to a rapid development of the modern building techniques and growing fatigue wear during utilization of bridges, market halls etc. The complexity and diversity of civil engineering structures impose requirements on the measuring system, which are difficult to be satisfied by a single sensor. As a solution, a complex monitoring system, composed of optical sensors as well as strain gauges and magnetic field sensors is being developed. In the paper the comparative study of different measurement techniques allowing for local deformation measurements will be presented. By application of a pair of video cameras the Digital Image Correlation technique allows for full-field in-plane and out-of-plane displacements measurements. By measuring the changes in magnetic field of analysed steel structure it is possible to obtain the diagnostic information about the type of strain and stress intensity. In the paper the results of optical and magnetic field measurements are compared to the strain gauge measurements obtained on the laboratory truss test stand.