Edinburgh Napier University

  The photogrammetric approach was proposed in this study to evaluate torsional behaviour of glulam timber beams during the torsion test. The main objectives of the experimental work were to investigate the applicability of the photogrammetric approach on the torsion test and to monitor more details of angles of twist of glulam timber beams subjected to torsional loading. Experimental tests were conducted on glulam timber beams subjected to torque, and the photogrammetric approaches as well as the inclinometers were employed to measure, respectively, the twists on the long and short sides of the cross section of the glulam specimens. The accuracy of the photogrammetric approach was validated by comparing the average rotations of the targets with those measured by the conventional inclinometer sensors. After validating the proposed approach, its measurements were compared with the inclinometer readings. The test results showed that the optical system allowed monitoring the rotations of the samples at different locations which would not be possible to obtain using the traditional techniques. The experimental results showed that there is a non-linearity from the measurement of the shear displacements along the long side of the cross-section. However, the average rotation shows clear agreements with the inclinometer readings.