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BEAM GLOBAL MODEL FOR THE SEISMIC ANALYSIS OF RC FRAMES
Author(s) -
MIRAMONTES D.,
MERABET O.,
REYNOUARD J. M.
Publication year - 1996
Publication title -
earthquake engineering and structural dynamics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.218
H-Index - 127
eISSN - 1096-9845
pISSN - 0098-8847
DOI - 10.1002/(sici)1096-9845(199607)25:7<671::aid-eqe573>3.0.co;2-f
Subject(s) - structural engineering , curvature , softening , envelope (radar) , stiffness , hardening (computing) , amplitude , seismic loading , mechanics , engineering , mathematics , materials science , physics , geometry , telecommunications , radar , statistics , layer (electronics) , quantum mechanics , composite material
A new hysteretic beam model based on a moment–curvature uniaxial cyclic law is proposed. The model is characterized by a trilinear envelope curve and a set of cyclic rules. The strength and stiffness degradation in the hardening and the softening branches as well as the hysteretic damping are directly dependent on the level and history of loading. Their continuous evolution is described with the aid of a new parameter based on energy criteria and phenomenological considerations. The model is capable of describing the dynamic response of RC frames with a minimum of input parameters. The characteristic points of the envelope curve are defined by three critical strain conditions at cross‐section level. A revision of ultimate compressive strain of concrete is used to start the softening behaviour of the envelope curve. The principal phenomena taken into account by the hysteretic rules are: stiffness degradation and strength reduction due to cyclic loading, pinching of loops due to shear stress, softening behaviour at failure and the effect of axial force due to gravity loads. The evolution of cyclic behaviour is controlled by a new cyclic parameter defined in terms of a damage index, an accommodation factor and the number of cycles with amplitude inferior to the maximum strain (curvature) ever experienced. This parameter allows the description of monotonic and cyclic response for both small and large deformations, including the post‐peak regime. In order to validate the proposed model, the global response of isolated members as well as a complete structure subjected to cyclic and dynamic loads are compared with experiments.