Experimental and numerical investigation of in-plane cyclic response of a point-fixed glass façade system for seismic performance assessment

This study investigates the seismic performance of point-fixed glass façade systems (PFGFS) through a full-scale experimental campaign conducted at the University of Coimbra. Two façade systems were tested, accounting for two fixing configurations: fully drilled countersunk bolts and partially through (embedded) bolts. Each system consisted of nine glass panels arranged in a 3 × 3 configuration, with individual panel dimensions of 1490 mm × 1490 mm. The façade systems were subjected to quasi-static cyclic loading to assess their in-plane drift response and post-fracture behaviour. Results indicate that failure initiated in the middle row, yet the façade system remained functional, sustaining additional loading cycles without complete failure. Maximum lateral drift ratios were 2.12 % for partially through bolts and 2.28 % for fully drilled bolts. Deformations were accommodated through rigid body motion, bolt rotation, and sealant relaxation, with washer yielding acting as a sacrificial mechanism to absorb deformation. The lamination foil played a crucial role in retaining shattered glass, ensuring post-failure integrity, and preventing the release of hazardous debris. A finite element model (FEM), validated against experimental results, successfully captured the façade's force-displacement response, confirming progressive failure behaviour. These findings highlight the ductility of point-fixed glass façade systems and demonstrate their capacity to sustain lateral displacement while maintaining structural stability. The results provide valuable insights into the deformation capacity of glass façades, enhancing the understanding of their safety and resilience in seismic regions.