numerical modelling of masonry infill walls participation in the seismic behaviour of rc buildings
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Numerical Modeling of masonry infill walls participation inthe seismic behavior of RC buildings
André Furtado | Hugo Rodrigues | António Arêdehugo.f.rodrigues@ipleiria.pt
Numerical Modeling of masonry infill walls participation inthe seismic behavior of RC buildings
André Furtado | Hugo Rodrigues | António Arêdehugo.f.rodrigues@ipleiria.pt
Numerical Modeling of masonry infill walls participation in the seismic behavior of RC buildings
Hugo Rodrigues | Workshop on Multi-Hazard Analysis of Structures using OpenSees – OpenSeesDays Portugal | Porto, July 03-04, 2014
Influence of masonry panels in buildings response
• Infill masonry panels are usually considered in the design of new structureshas non-structural elements, and its influence in the structural response isdisregarded
• Infill masonry panels may change drastically:• the global lateral stiffness and strength of the building structures• the natural frequencies and vibration modes• the energy dissipation capacity• a brittle behavior and failure mechanism
• Common infill masonry panels can modify drastically the global structuralbehavior attracting forces to parts of the structure that were not designed tosupport them, leading to unexpected behavior/response and collapsemechanisms
Numerical Modeling of masonry infill walls participation in the seismic behavior of RC buildings
Hugo Rodrigues | Workshop on Multi-Hazard Analysis of Structures using OpenSees – OpenSeesDays Portugal | Porto, July 03-04, 2014
Influence of masonry panels in buildings response
(Crisafulli, 2010)
Numerical Modeling of masonry infill walls participation in the seismic behavior of RC buildings
Hugo Rodrigues | Workshop on Multi-Hazard Analysis of Structures using OpenSees – OpenSeesDays Portugal | Porto, July 03-04, 2014
Types of failure of infills masonry walls
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Shear-friction failure Diagonal tension failure Crushing of the corners
Detachment frame-infillMonolitic behaviour
The seismic response of an infilled frame building structure is very complex, andusually 3 different damage or failure patterns/mechanisms can be distinguish:
Numerical Modeling of masonry infill walls participation in the seismic behavior of RC buildings
Hugo Rodrigues | Workshop on Multi-Hazard Analysis of Structures using OpenSees – OpenSeesDays Portugal | Porto, July 03-04, 2014
Observed damages in recent earthquakes - Field evidence
Possible causes: Balcony excessive deformation (cantilevers);dimensions of the masonry leafs; improper support conditions;poor connection conditions of the external leaf; no ties oranchoring systems either between inner and external leafs and/orbetween infill walls and the structural frame
Numerical Modeling of masonry infill walls participation in the seismic behavior of RC buildings
Hugo Rodrigues | Workshop on Multi-Hazard Analysis of Structures using OpenSees – OpenSeesDays Portugal | Porto, July 03-04, 2014
Observed damages in recent earthquakes - Field evidence
Damage to masonry enclosure walls – in-plane response (interfaceseparation between infills and resistant structure, diagonalcracking, corner crushing)
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Numerical Modeling of masonry infill walls participation in the seismic behavior of RC buildings
Hugo Rodrigues | Workshop on Multi-Hazard Analysis of Structures using OpenSees – OpenSeesDays Portugal | Porto, July 03-04, 2014
Observed damages in recent earthquakes - Field evidence
Damage to masonry enclosure walls – in-plane response (diagonal cracking)
Numerical Modeling of masonry infill walls participation in the seismic behavior of RC buildings
Hugo Rodrigues | Workshop on Multi-Hazard Analysis of Structures using OpenSees – OpenSeesDays Portugal | Porto, July 03-04, 2014
Observed damages in recent earthquakes - Field evidence
Out-of-plane failure of masonry enclosure walls
Numerical Modeling of masonry infill walls participation in the seismic behavior of RC buildings
Hugo Rodrigues | Workshop on Multi-Hazard Analysis of Structures using OpenSees – OpenSeesDays Portugal | Porto, July 03-04, 2014
Observed damages in recent earthquakes - Field evidence
Damage to infill masonry walls:
- in-plane response (interface separation between infills andresistant structure, diagonal cracking, corner crushing)
- out-of-plane collapse
Numerical Modeling of masonry infill walls participation in the seismic behavior of RC buildings
Hugo Rodrigues | Workshop on Multi-Hazard Analysis of Structures using OpenSees – OpenSeesDays Portugal | Porto, July 03-04, 2014
Observed damages in recent earthquakes - Field evidence
Short column mechanism
Possible cause: wall openings in masonry enclosures
Numerical Modeling of masonry infill walls participation in the seismic behavior of RC buildings
Hugo Rodrigues | Workshop on Multi-Hazard Analysis of Structures using OpenSees – OpenSeesDays Portugal | Porto, July 03-04, 2014
Modeling of infill masonry walls
Macro-models:
• More simplified than the micro-models
• Allow for a representation of the global
behavior of the infill masonry panels and
of their influence in the buildings
response
• Equivalent strut model is the most used
Infilled frames are complex structural systems and exhibit a highly nonlinear behavior.This fact complicates the analysis and explains why infill panels has been considered as"non-structural elements", despite their strong influence on the global response ofbuildings.
Micro-models:
• Detailed modeling
• Allow interpretation of the behavior at
local level
• Allow to obtain the cracking pattern, the
ultimate load, and the collapse
mechanisms
• High computational effort
• Need for a large number of parameter
• Useful for the calibration of global
models
Numerical Modeling of masonry infill walls participation in the seismic behavior of RC buildings
Hugo Rodrigues | Workshop on Multi-Hazard Analysis of Structures using OpenSees – OpenSeesDays Portugal | Porto, July 03-04, 2014
Modeling of infill masonry walls
The equivalent strut model was suggested by Poliakov andimplemented by Holmes and Stafford Smith in the 1960s.
Later, many researchers improved this basic model. Today, the strutmodel is accepted as a simple and rational way to represent the effectof the masonry infill panel in the global response of buildings.
The main advantage of themulti-strut models, in spiteof the increase ofcomplexity, is the ability torepresent the actions in theframe more accurately.
Numerical Modeling of masonry infill walls participation in the seismic behavior of RC buildings
Hugo Rodrigues | Workshop on Multi-Hazard Analysis of Structures using OpenSees – OpenSeesDays Portugal | Porto, July 03-04, 2014
Modeling of infill masonry walls
The typical strut models are not able of represent the response of theinfilled frame when horizontal shear sliding occurs in the masonrypanel. For this case, Leuchars & Scrivener proposed the modelillustrated.
A recent NZSEE Bulletin article, “Analytical modeling of infilled framestructures” [Crisafulli et al., 2000], provides a review of macro andmicro models, and reports on some comparative studies betweenequivalent strut models and FEM (‘solid’ element) models.
Numerical Modeling of masonry infill walls participation in the seismic behavior of RC buildings
Hugo Rodrigues | Workshop on Multi-Hazard Analysis of Structures using OpenSees – OpenSeesDays Portugal | Porto, July 03-04, 2014
Previous Research• Simplified global macro-model
• Represents the infill panel behaviour and its influence in the building response to seismic loadings
• An upgrading of the bi-diagonal strut model
• Considers the strength and stiffness degradation interaction in both directions of loading
• 4 strut elements with rigid linear behaviour that support a central element where the non-linear behaviour is concentrated
• Non-linear behaviour characterized by a monotonic curve with 5 branches for eachloading direction, and corresponding hysteretic rules
elemento
Não-Linear
Bielas
F
K0
K1
+
K2
+
K3
+
K4
+
u
F2
+
F1
+
F3
+
u1+
u2+ u3
+ u4+
1
2
3
4
5
Rodrigues, H.; Varum, H.; Costa, A. (2010) - Simplified macro-model for infill masonry panels -Journal of Earthquake Engineering, World Scientific Publishing, doi 10.1080/13632460903086044, Vol. 14, Issue 3, March 2010, pp. 390-416.
Numerical Modeling of masonry infill walls participation in the seismic behavior of RC buildings
Hugo Rodrigues | Workshop on Multi-Hazard Analysis of Structures using OpenSees – OpenSeesDays Portugal | Porto, July 03-04, 2014
Proposed approach
elasticBeamColumnStrut behavior in planeResidual stiffness in the OP direction
non-linearBeamColumnOnly with axial Non-linear behaviorPinching4
Numerical Modeling of masonry infill walls participation in the seismic behavior of RC buildings
Hugo Rodrigues | Workshop on Multi-Hazard Analysis of Structures using OpenSees – OpenSeesDays Portugal | Porto, July 03-04, 2014
Proposed approach
The uniaxial material Pinching 04 wasadopted to represent the hystereticrule
i) Cracking (cracking force Fc, crackingdisplacement dc)
ii) Yielding (yielding force Fy, yieldingdisplacement dy)
iii) Maximum strength correspondingto the beginning of crushing (Fcr andcorresponding displacement dcr)
iv) Residual strength (Residualstrength Fu and residual displacementdu)
The envelope can be obtained based on recommendations from past researchers (Zarnicand Gornic,1997 and Dolsek and Fajfar,2008) and observations from experimental tests(Mazounry,1995 and Shing et al, 2009) and from recommendation codes (FEMA)
Numerical Modeling of masonry infill walls participation in the seismic behavior of RC buildings
Hugo Rodrigues | Workshop on Multi-Hazard Analysis of Structures using OpenSees – OpenSeesDays Portugal | Porto, July 03-04, 2014
Numerical model calibration – One-storey one-bay infilled RC frame
• Reduced scale - 2/3
• Simplified masonry model
• Tests on sample materials of concrete and masonry used to calibrate the numerical model
0.15 0.420.150.42
0.35
0.20
0.165
1.625
4.20[ m ]
Numerical Modeling of masonry infill walls participation in the seismic behavior of RC buildings
Hugo Rodrigues | Workshop on Multi-Hazard Analysis of Structures using OpenSees – OpenSeesDays Portugal | Porto, July 03-04, 2014
Numerical model calibration – One-storey one-bay infilled RC frame
• Reduced scale - 2/3
• Simplified masonry model
• Tests on sample materials of concrete and masonry used to calibrate the numerical model
Without infill
0.15 0.420.150.42
0.35
0.20
0.165
1.625
4.20[ m ]
Numerical Modeling of masonry infill walls participation in the seismic behavior of RC buildings
Hugo Rodrigues | Workshop on Multi-Hazard Analysis of Structures using OpenSees – OpenSeesDays Portugal | Porto, July 03-04, 2014
Numerical model calibration – One-storey one-bay infilled RC frame
• Reduced scale - 2/3
• Simplified masonry model
• Tests on sample materials of concrete and masonry used to calibrate the numerical model
0.15 0.420.150.42
0.35
0.20
0.165
1.625
4.20[ m ]
Numerical Modeling of masonry infill walls participation in the seismic behavior of RC buildings
Hugo Rodrigues | Workshop on Multi-Hazard Analysis of Structures using OpenSees – OpenSeesDays Portugal | Porto, July 03-04, 2014
Numerical model calibration – One-storey one-bay infilled RC frame
• Good agreement betweennumerical and experimentalresults
• Model able to well representthe masonry strength andstiffness degradation,energy dissipation
Numerical Modeling of masonry infill walls participation in the seismic behavior of RC buildings
Hugo Rodrigues | Workshop on Multi-Hazard Analysis of Structures using OpenSees – OpenSeesDays Portugal | Porto, July 03-04, 2014
Numerical model calibration – One-storey one-bay infilled RC frame
Manzouri (1995) and Shing et al (2009) found that the maximum strength (Fmax) occurs at
approximately 0.25% drift
The maximum strength can be calculated through the equation proposed by Zarnic and
Gornic (1997) and later modified by Dolsek and Fajfar (2008).
)11(818.02
1
1
max
CC
ftLF tpin
Lin h'
t
'1 925.1h
LC in
ftp is the masonry cracking stress obtained based
on experimental test
Post-peak strength degradation or residual strength is based on Dolsek and Fajfar (2008)
that estimate that the displacement at residual strength is five times of the displacement
of maximum strength
Numerical Modeling of masonry infill walls participation in the seismic behavior of RC buildings
Hugo Rodrigues | Workshop on Multi-Hazard Analysis of Structures using OpenSees – OpenSeesDays Portugal | Porto, July 03-04, 2014
Numerical model calibration – One-storey one-bay infilled RC frame
Two different approaches were tested:
• Calibrated with experimental results
• Recommended parameters
Numerical Modeling of masonry infill walls participation in the seismic behavior of RC buildings
Hugo Rodrigues | Workshop on Multi-Hazard Analysis of Structures using OpenSees – OpenSeesDays Portugal | Porto, July 03-04, 2014
Numerical model calibration – One-storey one-bay infilled RC frame
• Good agreement betweennumerical and experimentalresults
• Model able to well representthe masonry strength andstiffness degradation,energy dissipation
Numerical Modeling of masonry infill walls participation in the seismic behavior of RC buildings
Hugo Rodrigues | Workshop on Multi-Hazard Analysis of Structures using OpenSees – OpenSeesDays Portugal | Porto, July 03-04, 2014
Numerical model calibration – One-storey one-bay infilled RC frame
Numerical Modeling of masonry infill walls participation in the seismic behavior of RC buildings
Hugo Rodrigues | Workshop on Multi-Hazard Analysis of Structures using OpenSees – OpenSeesDays Portugal | Porto, July 03-04, 2014
• 3D Models• Regular buildings
Under going work
PT4 PT8
4 Storeys3 bays x 5 bays
8 Storeys3 bays x 5 bays
Numerical Modeling of masonry infill walls participation in the seismic behavior of RC buildings
Hugo Rodrigues | Workshop on Multi-Hazard Analysis of Structures using OpenSees – OpenSeesDays Portugal | Porto, July 03-04, 2014
Under going work
PT4 PT8
4 Storeys3 bays x 5 bays
8 Storeys3 bays x 5 bays
• Dynamic time-history Analysis
• The building was submitted toseismic motions in order to berepresentative of a moderate-high European seismic hazardscenario
Numerical Modeling of masonry infill walls participation in the seismic behavior of RC buildings
Hugo Rodrigues | Workshop on Multi-Hazard Analysis of Structures using OpenSees – OpenSeesDays Portugal | Porto, July 03-04, 2014
Under going workPT4
PT8
Bare frama Full infilled soft-storey
Numerical Modeling of masonry infill walls participation in the seismic behavior of RC buildings
Hugo Rodrigues | Workshop on Multi-Hazard Analysis of Structures using OpenSees – OpenSeesDays Portugal | Porto, July 03-04, 2014
Under going workPT4
Numerical Modeling of masonry infill walls participation in the seismic behavior of RC buildings
Hugo Rodrigues | Workshop on Multi-Hazard Analysis of Structures using OpenSees – OpenSeesDays Portugal | Porto, July 03-04, 2014
Under going workPT8
Numerical Modeling of masonry infill walls participation in the seismic behavior of RC buildings
Hugo Rodrigues | Workshop on Multi-Hazard Analysis of Structures using OpenSees – OpenSeesDays Portugal | Porto, July 03-04, 2014
Final comment and future work• Masonry infill walls have a complex behavior due to the properties of their
materials and to the interaction mechanisms with the surrounding frame
• The response prediction of masonry infilled frame structures can be achievedby computational modeling. The application of simplified nonlinear numericalmodels, associated with the increasing computational power, allow for theinclusion of infill masonry models in the structural assessment of existingbuilding structures and in the design of new buildings
• The proposed infill masonry model was calibrated with the results of oneexperimental test. The numerical results shows that generally the modelproposed was able to represent the response of the structures in terms ofdisplacements evolution, and cumulative dissipated energy
• The proposed macro-model can be a useful tool in the development andcalibration of simplified rules for the analysis of infilled frame structuresunder horizontal loadings, accounting for important mechanical features ashysteretic behavior, strength and stiffness degradation, pinching and damageevolution, function of the deformation demands
• The main challenge is the possibility of considering the out-of-plane collapseof the infill masonry panel …. Under going work …
Numerical Modeling of masonry infill walls participation in the seismic behavior of RC buildings
Hugo Rodrigues | Workshop on Multi-Hazard Analysis of Structures using OpenSees – OpenSeesDays Portugal | Porto, July 03-04, 2014
Final comment and future work
Numerical Modeling of masonry infill walls participation in the seismic behavior of RC buildings
Hugo Rodrigues | Workshop on Multi-Hazard Analysis of Structures using OpenSees – OpenSeesDays Portugal | Porto, July 03-04, 2014
Obrigado!!!Thank you!!!
This research was developed under financial support provided by “FCT -Fundação para a Ciência e Tecnologia”, Portugal, namely through the research project PTDC/ECM/122347/2010 - RetroInf – Developing Innovative Solutions for Seismic Retrofitting of Masonry Infill Walls.
Numerical Modeling of masonry infill walls participation inthe seismic behavior of RC buildings
André Furtado | Hugo Rodrigues | António Arêdehugo.f.rodrigues@ipleiria.pt
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