Integrated Experimental-Numerical Study on Prestressed Concrete Girders for Structural Health Monitoring

This study combines full-scale testing with nonlinear FE modelling to develop SHM indicators for prestressed concrete bridge girders. Twelve 8 m beams (with bonded and unbonded tendons) were tested with a transverse diaphragm and a distributed dead load to simulate girder interaction. Progressive damage was introduced by staged strand cutting at the L/4, L/3, and L/2 spans. MEMS inclinometers provided direct tilt (rotation) profiles during loading and unloading. Damage localisation is inferred from the migration of the zero-tilt crossing and the concentration of rota-tion gradients near the damaged section. MEMS/piezoelectric accelerometers were used for opera-tional modal analysis to track frequency and mode-shape trends. A 3D ATENA nonlinear model reproduced the test sequence and supported the interpretation of damage effects. Results show that tilt-based signatures are highly sensitive to damage location and severity, while frequency shifts under service loads remain modest.