scholarly journals 3D FEA of Infilled RC Framed Structures Protected by Seismic Joints and FRP Jackets

2021 ◽  
Vol 11 (14) ◽  
pp. 6403
Author(s):  
Theodoros Rousakis ◽  
Vachan Vanian ◽  
Theodora Fanaradelli ◽  
Evgenia Anagnostou
Keyword(s):  
Seismic Protection ◽  
Rc Frame ◽  
Base Shear ◽  
Initial Stiffness ◽  
Framed Structures ◽  
Rc Structure ◽  
3D Fea ◽  
Ductile Behavior ◽  
Rc Framed Structures ◽  
Real Scale

This study focused on characteristic cases of recently tested real-scale RC framed wall infilled structures with innovative seismic protection through polyurethane joints (PUFJ) or polyurethane-impregnated fiber grids (FRPU). The frames revealed a highly ductile response while preventing infill collapse. Herein, suitable 3D pseudo-dynamic FE models were developed in order to reproduce the experimental results. The advanced Explicit Dynamics framework may help reveal the unique features of the considered interventions. Externally applied double-sided FRPU jackets on OrthoBlock infills may maintain an adequate bond with the surrounding RC frame as well as with the brick infill substrate at up to a 3.6% drift. In a weak four-column RC structure, the OrthoBlock infills with PUFJ seismic joints may increase the initial stiffness remarkably, increase the base shear by three times (compared with the bare structure) and maintain a high horizontal drift of 3.7%. After this phase, the structure may receive FRPU retrofitting, reveal the redistribution of stress over broad infill regions, including predamaged parts, and still develop a higher initial stiffness and base shear (compared with the bare RC). The realization of a desirable ductile behavior of infilled frames through PUFJ of only 20 mm thickness, as well as through FRPU jacketing, may remarkably broaden the alternatives in seismic protection against the collapse of structures.

scholarly journals Effect of Different Bracing Systems in Reinforced Concrete Frames under Cyclic Loading

2020 ◽  
Vol 9 (7) ◽  
pp. 704-708
Keyword(s):  
Reinforced Concrete ◽  
Cyclic Loading ◽  
Structural Parameters ◽  
Rc Frame ◽  
Concrete Frames ◽  
Element Analysis ◽  
Framed Structures ◽  
Rc Frames ◽  
Seismic Force ◽  
Rc Framed Structures

Reinforced concrete (RC) framed structures are widely used as load transferring system in residential and commercial buildings. Even though the RC frames are designed for gravitational and seismic forces, but they are week under severe seismic events. The main disadvantage of the framed structures is inefficient bracing systems designed in it. This investigation is conducted mainly to study the effective bracing system in the RC framed structure to transfer the seismic force. This research aims to study the seismic performance of RC frames influenced by the various types of cross bracings under cyclic loading. The finite element analysis software package ABAQUS is used to investigate the braced RC frames analytically. The research scheme consists of three RC frames; the bare frame, the bare frame with single X-bracing (X frame), double X bracing (D-X frame) along the height. The structural parameters include, load-displacement hysteresis envelope, stiffness degradation and energy absorption were studied to analyze the performance of bracings. The results showed that the X frame and D-X frame noticeably increased the lateral strength, stiffness and energy dissipation properties compared to the bare RC frame. The results also indicated that the addition of X bracing along the height significantly enhanced the structural parameters of the RC frame.

scholarly journals Response Reduction Factor for Different Heights of RC Structure

2019 ◽  
Vol 9 (2) ◽  
pp. 3273-3276
Keyword(s):  
Seismic Analysis ◽  
Pushover Analysis ◽  
Reduction Factor ◽  
Framed Structures ◽  
Response Reduction Factor ◽  
Rc Structure ◽  
Non Linear ◽  
Linear Behaviour ◽  
Rc Framed Structures ◽  
Strength And Ductility

Seismic analysis is considered as an important parameter for any structural design. The strength and ductility of frame members in seismic design depends on the response reduction factor. In this paper four symmetrically framed structures are considered of different heights under the critical zone condition. The primary emphases of this work is regarding calculation of response reduction factor values attained from designing RC framed structures. The results are computed by applying non-linear static pushover analysis. SAP-2000 software is used for analyzing the non-linear behaviour of the structure.

scholarly journals Comparison of Novel Seismic Protection Devices to Attenuate the Earthquake Induced Energy

Actuators ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 73
Author(s):  
Osman Hansu ◽  
Esra Mete Güneyisi
Keyword(s):  
Lateral Displacement ◽  
Time History ◽  
Seismic Protection ◽  
Base Shear ◽  
Seismic Demands ◽  
Nonlinear Time History Analyses ◽  
History Of ◽  
Protection Devices ◽  
Nonlinear Time History ◽  
Better Than

This study addresses an alternative use of viscous dampers (VDs) associated with buckling restrained braces (BRBs) as innovative seismic protection devices. For this purpose, 4-, 8- and 12-story steel bare frames were designed with 6.5 m equal span length and 4 m story height. Thereafter, they were seismically improved by mounting the VDs and BRBs in three patterns, namely outer bays, inner bays, and all bays over the frame heights. The structures were modeled using SAP 2000 software and evaluated by the nonlinear time history analyses subjected to the six natural ground motions. The seismic responses of the structures were investigated for the lateral displacement, interstory drift, absolute acceleration, maximum base shear, and time history of roof displacement. The results clearly indicated that the VDs and BRBs reduced seismic demands significantly compared to the bare frame. Moreover, the all-bay pattern performed better than the others.

scholarly journals Numerical Modeling of Masonry-infilled RC Frame

2019 ◽  
Vol 13 (1) ◽  
pp. 135-148 ◽  
Author(s):  
Christiana A. Filippou ◽  
Nicholas C. Kyriakides ◽  
Christis Z. Chrysostomou
Keyword(s):  
Cyclic Loading ◽  
Numerical Model ◽  
Constitutive Models ◽  
Control Analysis ◽  
Rc Frame ◽  
Initial Stiffness ◽  
Element Analysis ◽  
Rc Frames ◽  
Rc Frame Structures ◽  
Infilled Rc Frames

Background: The behavior of masonry-infilled Reinforced Concrete (RC) frame structures during an earthquake, has attracted the attention of structural engineers since the 1950s. Experimental and numerical studies have been carried out to investigate the behavior of masonry-infilled RC frame under in-plane loading. Objective: This paper presents a numerical model of the behavior existing masonry-infilled RC frame that was studied experimentally at the University of Patra. The objective of the present study is to identify suitable numerical constitutive models for each component of the structural system in order to create a numerical tool to model the masonry infilled RC frames in-plane behavior by accounting the frame-infill separation. Methods: A 2D masonry-infilled RC frame was developed in DIANA Finite Element Analysis (FEA) software and an eigenvalue and nonlinear structural cyclic analyses were performed. It is a 2:3 scale three-story structure with non-seismic design and detailing, subjected to in-plane cyclic loading through displacement control analysis. Results: There is a good agreement between the numerical model and experimental results through a nonlinear cyclic analysis. It was found that the numerical model has the capability to predict the initial stiffness, the ultimate stiffness, the maximum shear-force capacity, cracking- patterns and the possible failure mode of masonry-infilled RC frame. Conclusion: Therefore, this model is a reliable model of the behavior of masonry-infilled RC frame under cyclic loading including the frame-infill separation (gap opening).

scholarly journals Seismic Performance of Multistorey RC Frame Building With The Soft Storey and Masonry Infill

2021 ◽  
pp. 650-656
Author(s):  
Kugan K ◽  
Mr. Nandha Kumar P ◽  
Premalath J
Keyword(s):  
Time History ◽  
Seismic Loading ◽  
Rc Frame ◽  
Base Shear ◽  
Maximum Displacement ◽  
Soft Storey ◽  
Masonry Infills ◽  
Frame Building ◽  
History Analysis ◽  
Rc Frame Building

In this study, four geometrically similar frames having different configurations of masonry infills, has been investigated. In this article attempts are made to explain the factors that impact the soft storey failure in a building are compared with different type of infill. That is Four models like RC bare frame, RC frame with brick mansonry infill, RC frame with brick infill in all the storeys exept the firstsoft storey, RC frame with inverted V bracing in the soft storey. Time history analysis has been carried out for a G+8 multistoried building to study the soft storey effect at different floor levels using E tabs software. The behavior of RC framed building with soft storey under seismic loading has been observed in terms of maximum displacement ,maximum storey drift, base shear and storey stiffness as considered structure.

Pseudodynamic Test of a Deficient RC Frame Strengthened with Buckling Restrained Braces

2019 ◽  
Vol 35 (3) ◽  
pp. 1163-1187 ◽  
Author(s):  
Ramazan Ozcelik ◽  
Elif Firuze Erdil
Keyword(s):  
Time History ◽  
Shear Capacity ◽  
Test Method ◽  
Nonlinear Time History Analysis ◽  
Rc Frame ◽  
Test Results ◽  
Base Shear ◽  
Braced Frame ◽  
Pseudodynamic Test ◽  
Buckling Restrained Braces

Three story–three bay reinforced concrete (RC) frames with and without chevron braces were tested using the continuous pseudodynamic test method. New steel–concrete composite lateral load–carrying members called Buckling Restrained Braces (BRBs) were used as chevron brace members while retrofitting the RC frame. The BRBs were fitted to the interior span of the RC frame by using anchorage rods. The chevron braced frame was observed to be effective in controlling interstory drift. The test results indicated that retrofitting with BRBs was beneficial in resisting deformation without significant damage under simulated ground motions. Furthermore, significant yielding that occurred on the core plate of the BRBs enabled the braced frame to dissipate energy induced by dynamic loading. The test results were compared with the results of the nonlinear time-history analysis. The analysis results were capable of estimating the base shear capacity and displacement demands with reasonable accuracy.

Cyclic Performance of Two-Story Ductile RC Frames With Infill Walls

2005 ◽  
Author(s):  
Yung-Hsin Yeh ◽  
Wen-I Liao
Keyword(s):  
Model Building ◽  
General Purpose ◽  
Rc Frame ◽  
Building Structures ◽  
Base Shear ◽  
Concrete Frames ◽  
Infill Wall ◽  
Infill Walls ◽  
Rc Frames ◽  
Short Beam

This paper presents the results of the experimental and analytical investigations conducted on four 0.8 scale 2-story one bay ductile reinforced concrete frames with infill nonstructural walls subjected to cyclically increasing loads. The material properties and the member sizes of beams and columns in the four RC frame specimens are identical, but with different types of infill nonstructural wall. These four frames are the pure frame, frame with short column, frame with short beam and frame with wing walls. The four RC frame specimens were designed and constructed according to the general prototype building structures in Taiwan. Test results indicate that the ductility behavior of the frames with infill wall is similar to those of the pure frame. The ultimate base shear strength of the frames with infill walls is higher than those of the pure frame. Analytical results show that the proposed simplified multi-linear beam-column element implemented in a general purpose structural analysis program can accurately simulate the cyclic responses of the RC frame specimen incorporating the elastic flexural stiffness computations suggested by the model building codes.

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