Search results for "RC frame"
showing 7 items of 7 documents
Seismic Performance of Earthquake-Resilient RC Frames Made with HSTC Beams and Friction Damper Devices
2021
Seismic behavior of RC frames with hybrid steel-trussed concrete beams is affected by panel zone damage due to a large amount of longitudinal reinforcement. Here the seismic efficiency of innovative frames characterized by friction damper devices (FDDs) at beam-to-column connections is compared against traditional frame. Three configurations are investigated: FDDs alone; FDDs with column-to-foundation connections having preloaded threaded bars and disk springs; FDDs with self-centering friction devices. Non-linear analyses show that FDDs alone prevent plastic hinge formation at beam ends and beam–column joint damage. FDDs with self-centering friction devices effectively limit both peak and …
Masonry infills and RC frames interaction: Literature overview and state of the art of macromodeling approach
2015
The issue of the influence of masonry infills within RC frames structures has been widely investigated in the last decades by several researchers. The large interest addressed to this topic depends on the actual observation that when in presence of seismic events, the response of framed structures is strongly conditioned by the interaction with the infill walls, which however are considered as non-structural elements and not included in the models. The influence of masonry infills role in structural response is so much relevant to affect not only the overall strength and the stiffness but it may also radically change the possible collapse mechanisms of the overall structural complex under t…
Analysis of local shear effects in brick masonry infilled RC frames
2013
Masonry infills panels placed among framed structures meshes have a relevant influence in presence seismic actions in terms of strength stiffness and global displacement capacity. In the case of RC structures, the modifications of internal forces due to infill-frame interaction may be not compatible with surrounding frame members strength especially considering additional shear forces arising at the ends of beams and columns in contact with the panel under lateral actions. Such effects may be in many cases the cause of unexpected brittle collapse mechanisms which compromise the safety of the entire structure. In this paper by means of a double (micromodeling and macromodeling) procedure reg…
Influence of column shear failure on pushover based assessment of masonry infilled reinforced concrete framed structures: A case study
2017
Structural frames, constructed either of steel or reinforced concrete (RC), are often infilled with masonry panels. However, during the analysis of the structural frames, it has become common practice to disregard the existence of infills because of the complexity in modeling. This omission should not be allowed because the two contributions (of infills and of frames) complement each other in providing a so different structural system. The use of different modeling assumptions significantly affects the capacity as well as the inelastic demand and safety assessment. In specific, the adoption of equivalent diagonal pin-jointed struts leaves open the problem of the evaluation of the additional…
Prediction Equations for Out-of-Plane Capacity of Unreinforced Masonry Infill Walls Based on a Macroelement Model Parametric Analysis
2021
In the seismic performance assessment of reinforced concrete (RC) frames, a reliable estimation of the capacity of unreinforced masonry (URM) infill walls is of utmost importance to ensure structural safety conditions. With particular attention to the out- of-plane (OoP) capacity of URM infill walls after in-plane (IP) damage, the issue of defining reliable analytical prediction models for the assessment of the capacity is an ongoing study. In this paper, empirical equations are proposed for the evaluation of the infilled frame’s OoP capacity, with or without IP damage, based on an extensive numerical parametric analysis, focusing on the influence of the key parameters that govern the mecha…
Genetic Optimization for the design of seismic retrofitting of plane RC frames with Buckling Restrained Braces (BRBs)
2021
The increasing development of computational power in modern digital devices has spread the use of structural optimization in design applications of different fields of engineering problems. This approach exposes engineers to challenging design procedures aimed to optimize all variables to satisfy the imposed requirements, finding the “optimal” solution. Despite this wide use, the application of optimization algorithms for the design of seismic retrofitting strategies becomes tougher, due to the difficulties in finding a mathematical expression which includes and combines all the key variables (i.e., cost, safety, sustainability, design) and the nonlinearity of the analysis. In this paper, t…
A new FEM approach for FRP-strengthened RC frames
2017
Owing special mechanical properties has made Fiber Reinforced Polymer (FRP) as one of the best strengthening materials for Reinforced Concrete (RC) structures. The effect of externally applied FRP sheets on RC elements has been the topic of many experimental investigations. On the other hand, simulating the behavior of RC structures strengthened by means of externally bonded FRP sheets is yet to be scrutinized. In this work, a new Finite Element (FE) procedure for inelastic analysis of RC structures has been enriched to account the presence of externally bonded FRP sheets on RC sections. The proposed FE procedure works in the framework of lumped plasticity. It is able to identify the exact …