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S. Lu, R. Heuer, R. Flesch, M. Ralbovsky:
"Material Model For URM With A Application On The Seismic Assessment Of A Hospital In Tyrol, Austria";
in: "Proceedings of 22nd Biennal Conf. Concrete, 17-19 Oktober 2005", Proceedings of 22nd Biennal Conf. Concrete, Melbourne, Australia, 2005, ISBN: 0909375704.

The content of this paper presents a new model for unreinforced masonry (URM), based on the plastic material model by Ganz [1]. Here, the idea of Ganz [1] was followed, to use a combination of yielding surfaces in the stress space, where each surface describes one failure mode. Compared to the material model of Ganz [1], the new model was extended to cover even the tension strength aspects of masonry constructions in both directions (in plane, orthogonal and parallel to the horizontal joints) for each failure mode. The model still consists of only 5 convex yielding surfaces which describe the following failures, respectively:

-) tension failure
-) compression failure
-) shear failure
-) sliding along the horizontal joints
-) tension failure in the horizontal joints

Additionally to the theoretical background an application is shown, where laboratory experiments are used to test and calibrate the material model and its parameters. Therefore, this model was implemented into the Finite Element Software ANSYS. The implementation involves all the failure modes and an automatic searching for the positions of the masonry structures in the global FE-model. The result of this numerical implementation is the display of the cracked and yielded areas of the wall, respectively. The accuracy depends on the size of the finite elements chosen in the model.
Furthermore, this model was applied to seismic assessment of a hospital located in Innsbruck, Tyrol, Austria. In a first step, in-situ measurements have been carried out to detect the dynamic parameters (natural frequencies and mode shapes) for updating the finite element model with these properties. Afterwards, the FE-model was analyzed by response spectra method using SRSS combination rule to simulate a code earthquake, as required in the Austrian national code for designing of buildings with seismic actions, ÖNORM B 4015 [9]. Finally, the new material model was introduced to display cracks in the structure occurring due to the earthquake excitation.

http://aleph.ub.tuwien.ac.at/F?base=tuw01&func=find-c&ccl_term=AC05935042