1,931 research outputs found
An elastic-plastic interface model for fracture of quasi brittle materials
No full textTECHICAL REPORT - Università degli Studi di Bresci
Cyclic Analyses of Reinforced Concrete Masonry Panels Using a Force-Based Frame Element
No full textThis paper presents the calibration of a frame element that can be used to model the flexural as well as the shear behavior of reinforced masonry panels subjected to monotonic and cyclic loads. The element can be used in the equivalent frame method to analyze masonry wall systems, and is based on a force-based Timoshenko beam element formulation that combines a fiber-section model with a phenomenological nonlinear shear law. The element was originally applied to the analysis of reinforced concrete frames, and has been recently extended to unreinforced masonry structures. Well-established constitutive laws are used for masonry and steel reinforcement. The constitutive law for shear requires special attention in order to correctly predict the shear force-deformation response of masonry walls, accounting for the presence of shear reinforcement. A procedure to calibrate the parameters of the shear law is presented. The effectiveness, accuracy, and simplicity of the force-based Timoshenko frame element and the calibration method are validated by results of experimental tests. Even though the element is general and can model any reinforced masonry panel, the applications of this paper focus on panels made of hollow concrete blocks
MODELLING IN-PLANE AND OUT-OF-PLANE RESPONSE OF INFILLED FRAMES THROUGH A FIBER MACRO-MODEL
No full textA new fiber macro-model for the simulation of combined in-plane and out-of plane response of infilled frames subjected to seismic actions is presented in the paper. The model consists of 4 pinned struts (two diagonals, one horizontal and one vertical) modeled with the nonlinear beam/column fiber-section elements available in OpenSees. The model is particularly suitable to predict the out-of-plane response as fiber-section elements can account for the coupling between axial load and bending moment occurring because of the arching mechanism developed by the infills beyond the first cracking. Moreover the model can account for the effect of the reciprocal damaging accumulated both in-plane and out-of-plane during shakings. The procedure for the identification of the struts is presented in the paper and is validated with experimental test data from different authors. The proposed model may be used as a computationally-light and effective tool for the assessment of the response of 3D structures subjected to ground motions acting in arbitrary directions
A REINFORCED CONCRETE MODEL FOR ANALYZING FLEXURAL AND SHEAR BEHAVIOR OF R/C BEAM-COLUMNS
No full text
A REINFORCED CONCRETE MODEL FOR ANALYZING FLEXURAL AND SHEAR BEHAVIOR OF R/C BEAM-COLUMNS
No full textPrediction of the out-of-plane response of infilled frames under seismic loads by a new fiber-section macro-model
No full textDuring an earthquake the in-plane response of infills interacts with the out-of-plane response, primarily governed by the arching mechanism developed because of the boundary frame. The assessment of the out-of-plane capacity of infills and its reciprocal dependence with in-plane damage constitutes an open question. The paper suggests an extension of the capability of the traditional inplane macro-models to capture the simultaneous in-plane and out-of-plane response of infills. A practical modelling procedure is proposed and validated using experimental data. The possibility to simulate the arching action is achieved by using distributed plasticity fiber-section elements, able to directly account for the coupling between axial load and bending moment
- …
