Verification of the photogrammetric approach on the torsion test method for timber beams

ABSTRACT The photogrammetric approach was proposed in this study to evaluate torsional behaviour of glulam timber beams during the torsion test. The main objectives were to investigate the applicability of the photogrammetric approach and to monitor more details of angles of twist of glulam timber beams. Experiments were conducted and the twists on long and short sides of the cross section were measured using the photogrammetric approach and inclinometer sensors, which were used to validate the accuracy. 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 results also 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.