Comparative assessment of strut models for the modelling of in-plane seismic response of infill walls

摘要

The influence of infills on the seismic response of frame structures has long been\udrecognised. Typically, stiffness and strength of the infill and connections between infill and\udframe are such that the infill affects the global seismic behaviour of the structure. Hence, the\udpresence of infills should be considered in the analysis and design of new buildings and in the\udseismic assessment of existing ones. To this aim, simple models for infill walls, such as the\udequivalent diagonal no-tension strut model, have been developed in the last decades. The objective\udof the present study is to assess the validity of different strut models. To this aim, 162\udexperimental tests available in the literature are considered. The data set includes both reinforced\udconcrete and steel frames, as well as confined masonry structures. The mechanical\udcharacteristics of masonry and the boundary conditions between frames and infills of the test\udspecimens take into account a large set of situations, reflecting the great variability in the materials\udand in the construction techniques adopted in different countries. Moreover, the type\udof tests and the related results are not uniform; in some cases monotonic experiments are performed,\udwhereas in other cases cyclic tests are carried out. As expected, the presence of different\udtypes of infill-frame systems results in a large scatter of the data. However, the\udcomparison between experimental results and predictions show that, on the average, the infill\udstrength can be adequately estimated by resorting to the strut model whereas major uncertainties\udare found for the stiffness prediction.