Modal Analysis of Masonry Structures
  This paper presents a new numerical procedure for evaluating the vibration frequencies and mode shapes of masonry buildings in the presence of cracks. The algorithm has been implemented within the NOSA-ITACA code, which models masonry as a nonlinear elastic material with zero tensile strength. Some case studies are reported, and the differences between linear and nonlinear behavior highlighted. 
Maria Girardi, Cristina Padovani, Daniele Pellegrini
cs.CE