Investigación de las condiciones geométricas y físicas que favorecen la formación de diafragmas flexibles mediante modelamiento matemático lineal y no lineal usando SAP2000.

Abstract

This work aims to analyze the geometric and physical characteristics that contribute to the formation of flexible diaphragms, using models with different conditions. With SAP2000 program. The diaphragms are studied with a nonlinear structural model for horizontal load, tranfer thru which the nonlinear diaphragms are classified by their approximation to an infinitely flexible diaphragm in which the load is distributed according to tributary masses, or by their approximation to a rigid diaphragm where the shear distribution is a function of frame stiffnesses. Diaphragms where found to fall in an intermediate condition, in which the shear distribution depends on the stiffness of the diaphragm members and frames. As the diaphragm deforms and cracks inshear in its own plane, the horizontal load distribution within the diaphragm is initially a stiffness function and then slightly approaches to a distribution that is a function of the tributary masses to frames. With respect to modeling, an axial strut was used to model the diaphragm nonlinear properties, and the structure is solved by nonlinear static Pushover analysis using SAP2000. Seismic results from analyses show variations in the shear distribution to elements, depending on stiffness degradation of diaphragms.