Application of sequentially linear analysis to the seismic assessment of slender masonry towers

摘要

Brittle failure behavior is an intrinsic characteristic of slender masonry towers that behave asrncantilever beams. The application of the classical nonlinear finite element analysis (NLFEA) methods for thernseismic assessment of such structures often involves difficulties in the definition of post-peak behavior, whichrncan be characterized by a sudden decay. In order to investigate the post-peak behavior of such structures thernSequentially LinearAnalysis (SLA) method has been used as possible alternative tool to the usual nonlinear staticrnanalysis methods. Both NLFEA and SLA have been applied to a historical Italian masonry tower. A 2D planernstress and a 3D solid finite element model of the tower have been set up. The nonlinear behavior of the masonryrnmaterial, both in tension and compression, has been taken into account. The different modeling approaches andrnthe different analysis methods allowed for the comparison of the results. NLFEA showed a very brittle collapse,rnwith convergence problems after the attainment of the peak load. The application of SLA confirmed the resultsrnof NLFEA in terms of base shear-top displacement curves and in terms of damage patterns at the peak load. Inrnaddition SLA allowed for the investigation of the post-peak behavior and confirmed the very brittle nature ofrncollapse of the tower, since equilibrium has no longer been found after the peak. In conclusion, the applicationrnof SLA to the case study demonstrated the potential of the SLA method as alternative and very robust tool forrnseismic assessment of masonry towers.