Modelling RC masonry infilled frames under earthquake loading:...

Modelling RC masonry infilled frames under

earthquake loading: from accurate micro-models

to simplified macro-models.

Student name:

Hossameldeen Mohamed Ahmed

Supervisor:

Prof. Xavier Romão

2016

PhD 2016 | 2

2016 CONSTRUCT PhD Workshop

b) Infill shear and major frame damages,

Chania 2008 a) Infill shear and minor frame damages,

Nepal 2015

c) A collapsed soft storey apartment

building in the Marina District, San

Francisco 1989 (Loma Prieta Earthquake)

d) Damage to an apartment building with

a soft first storey in Bordj-Kiffan city,

Algeria 2003

Motivation and objectives

• Based on the observations of several recent earthquakes, the vulnerability of the

masonry-infilled RC frames is clear.

PhD 2016 | 3


• Based on the observations of several recent earthquakes, the vulnerability of the

masonry-infilled RC frames is clear.

• In order to assess the structural contribution of the infill panel to the structural

behaviour, a realistic model for the infill panel is urgently needed.

Tasks

• Define the best model to simulate the behaviour of masonry-infilled RC structures.

o A comprehensive review of existing macro-models (single strut model)

o Numerical calibration of the proposed models’ parameters (based on

stiffness or strength characteristics)

o Experimental calibration of the proposed models’ parameters

o Micro-modelling approach as a proxy for the experimental data

Motivation and objectives

PhD 2016 | 4


A comprehensive review of the existing macro-models (strut model)

• Polyakov’s experimental observation on the late 1950s

Infill panel works as a bracing for the RC frame

• Several attempts have been carried out to define the configuration and

structural parameters of this equivalent element.

Various examples of strut models

PhD 2016 | 5


A comprehensive review of the existing macro-models (strut model)

• Polyakov’s experimental observation on the late 1950s

• Several attempts have been carried out to define the configuration and

structural parameters of this equivalent element.

• Using a single strut element provides a simplified and efficient way to

represent the effect of the infill panel on the structural behaviour of the building

o Based on the literature, the calibration of the single strut model could

be done through main approach:

Stiffness approach.

Area of strut (several formulas are found)

Constitutive model for the equivalent material.(based on the masonry compressive strength fm)

Strength approach

Force-displacement backbone curve.

Calibration of the single strut model

d

whwh

Lw

L

PhD 2016 | 6


Stiffness approach.

0

10

20

30

40

50

60

Yie

ld f

orc

eth

eore

tical

/Yie

ld f

orc

eexperim

enta

l

Spec

imen

III/2

Spec

imen

S

Spe

cimen

F t1

Spec

imen

M2

Spec

imen

DFS

Spec

imen

F 1

Spec

imen

6

Spec

imen

7

Spec

imen

5

Spec

imen

11

Spec

imen

12

Spec

imen

4

Spec

imen

SBF

Spec

imen

IS

Spec

imen

unit 1

Holmes 1961

Mainstone 1971

Te-chang et al, 1984

Decanini et al.1987

Moghaddam et al. 1988

Hendry 1990

Paulay ,et al. 1992

Durrani and Luo, 1994

0

10

20

30

40

50

60

Max.

forc

e theore

tical

/Max.

forc

e experim

enta

l

Spec

imen

III/2

Spec

imen

S

Spe

cimen

F t1

Spec

imen

M2

Spec

imen

DFS

Spec

imen

F 1

Spec

imen

6

Spec

imen

7

Spec

imen

5

Spec

imen

11

Spec

imen

12

Spec

imen

4

Spec

imen

SBF

Spec

imen

IS

Spec

imen

unit 1

Holmes 1961

Mainstone 1971


Decanini et al.1987


Hendry 1990

Paulay ,et al. 1992


0

2

4

6

8

10

12

14

16

18

Km

(experim

enta

l)/K

m (

experim

enta

l)

Spec

imen

III/2

Spec

imen

S

Spe

cimen

F t1

Spec

imen

M2

Spec

imen

DFS

Spec

imen

F 1

Spec

imen

6

Spec

imen

7

Spec

imen

5

Spec

imen

11

Spec

imen

12

Spec

imen

4

Spec

imen

SBF

Spec

imen

IS

Spec

imen

unit 1

Holmes 1961

Mainstone 1971


Decanini et al.1987


Hendry 1990

Paulay ,et al. 1992


0

1

2

3

4

5

6

7

K1th

eore

tical

/K1experim

enta

l

Spec

imen

III/2

Spec

imen

S

Spe

cimen

F t1

Spec

imen

M2

Spec

imen

DFS

Spec

imen

F 1

Spec

imen

6

Spec

imen

7

Spec

imen

5

Spec

imen

11

Spec

imen

12

Spec

imen

4

Spec

imen

SBF

Spec

imen

IS

Spec

imen

unit 1

Holmes 1961

Mainstone 1971


Decanini et al.1987


Hendry 1990

Paulay ,et al. 1992


• 8 different formulas were used to evaluate the width of the strut

for 15 fully infilled specimens from 10 experimental campaigns

PhD 2016 | 7


Strength approach.

• 3 different formulas were used to evaluate the force-displacement curve

of the strut for 15 fully infilled specimens from 10 experimental campaigns

0

1

2

3

4

5

6

7

8

Max.

forc

e theore

tical

/Max.

forc

e experim

enta

l

Spec

imen

III/2

Spec

imen

S

Spe

cimen

F t1

Spec

imen

M2

Spec

imen

DFS

Spec

imen

F 1

Spec

imen

6

Spec

imen

7

Spec

imen

5

Spec

imen

11

Spec

imen

12

Spec

imen

4

Spec

imen

SBF

Spec

imen

IS

Spec

imen

unit 1

Dolšek, et al. (2008)

Panagiotakos, et al. (1996)

Bertoldi, et al. (1993)

0

10

20

30

40

50

Km

(experim

enta

l)/K

m (

experim

enta

l)

Spec

imen

III/2

Spec

imen

S

Spe

cimen

F t1

Spec

imen

M2

Spec

imen

DFS

Spec

imen

F 1

Spec

imen

6

Spec

imen

7

Spec

imen

5

Spec

imen

11

Spec

imen

12

Spec

imen

4

Spec

imen

SBF

Spec

imen

IS

Spec

imen

unit 1




0

1

2

3

4

5

6

7

8

Yie

ld f

orc

eth

eore

tical

/Yie

ld f

orc

eexperim

enta

l

Spec

imen

III/2

Spec

imen

S

Spe

cimen

F t1

Spec

imen

M2

Spec

imen

DFS

Spec

imen

F 1

Spec

imen

6

Spec

imen

7

Spec

imen

5

Spec

imen

11

Spec

imen

12

Spec

imen

4

Spec

imen

SBF

Spec

imen

IS

Spec

imen

unit 1




0

5

10

15

20

25

K1th

eore

tical

/K1experim

enta

l

Spec

imen

III/2

Spec

imen

S

Spe

cimen

F t1

Spec

imen

M2

Spec

imen

DFS

Spec

imen

F 1

Spec

imen

6

Spec

imen

7

Spec

imen

5

Spec

imen

11

Spec

imen

12

Spec

imen

4

Spec

imen

SBF

Spec

imen

IS

Spec

imen

unit 1




PhD 2016 | 8


Experimentally-based calibration

• Force-displacement curve is defined

• Several formulas are used to estimate the area of the strut.

• Based on the max. force and the numerical area of the strut obtained, a fictitious strength is

calculated. This strength defines the material of the strut instead of the real masonry material.

Fully infilled specimens

- specimen M2

- specimen S

Partially infilled specimens

- specimen DO2

- specimen DX1

- specimen WO2

- specimen WX1

-6 -4 -2 0 2 4 6-150-75

075

150Holmes 1961

-6 -4 -2 0 2 4 6-150-75

075

150Mainstone 1971

-6 -4 -2 0 2 4 6-150-75

075

150

Base S

hear

(kN

) Te-chang et al, 1984

-6 -4 -2 0 2 4 6-150-75

075

150Decanini et al.1987

-6 -4 -2 0 2 4 6-150-75

075

150Mohghaddam et al. 1988

-6 -4 -2 0 2 4 6-150-75

075

150Hendry 1990

-6 -4 -2 0 2 4 6-150-75

075

150

Drift (%)

Paulay,et al. 1992

-6 -4 -2 0 2 4 6-150-75

075

150Durrani and Luo, 1994

Drift (%)

Numerical model Experimental Data

-4 -3 -2 -1 0 1 2 3 4-120-60

060

120Holmes 1961

-4 -3 -2 -1 0 1 2 3 4-120-60

060

120Mainstone 1971

-4 -3 -2 -1 0 1 2 3 4-120-60

060

120

Base S

hear

(kN


-4 -3 -2 -1 0 1 2 3 4-120-60

060


-4 -3 -2 -1 0 1 2 3 4-120-60

060


-4 -3 -2 -1 0 1 2 3 4-120-60

060

120Hendry 1990

-4 -3 -2 -1 0 1 2 3 4-120-60

060

120

Drift (%)

Paulay,et al. 1992

-4 -3 -2 -1 0 1 2 3 4-120-60

060


Drift (%)


-4 -3 -2 -1 0 1 2 3 4-120-60

060

120Holmes 1961

-4 -3 -2 -1 0 1 2 3 4-120-60

060

120Mainstone 1971

-4 -3 -2 -1 0 1 2 3 4-120-60

060

120

Base S

hear

(kN


-4 -3 -2 -1 0 1 2 3 4-120-60

060


-4 -3 -2 -1 0 1 2 3 4-120-60

060


-4 -3 -2 -1 0 1 2 3 4-120-60

060

120Hendry 1990

-4 -3 -2 -1 0 1 2 3 4-120-60

060

120

Drift (%)

Paulay,et al. 1992

-4 -3 -2 -1 0 1 2 3 4-120-60

060


Drift (%)


-4 -3 -2 -1 0 1 2 3 4-120-60

060

120Holmes 1961

-4 -3 -2 -1 0 1 2 3 4-120-60

060

120Mainstone 1971

-4 -3 -2 -1 0 1 2 3 4-120-60

060

120

Base S

hear

(kN


-4 -3 -2 -1 0 1 2 3 4-120-60

060


-4 -3 -2 -1 0 1 2 3 4-120-60

060


-4 -3 -2 -1 0 1 2 3 4-120-60

060

120Hendry 1990

-4 -3 -2 -1 0 1 2 3 4-120-60

060

120

Drift (%)

Paulay,et al. 1992

-4 -3 -2 -1 0 1 2 3 4-120-60

060


Drift (%)


-4 -3 -2 -1 0 1 2 3 4-120-60

060

120Holmes 1961

-4 -3 -2 -1 0 1 2 3 4-120-60

060

120Mainstone 1971

-4 -3 -2 -1 0 1 2 3 4-120-60

060

120

Base S

hear

(kN


-4 -3 -2 -1 0 1 2 3 4-120-60

060


-4 -3 -2 -1 0 1 2 3 4-120-60

060


-4 -3 -2 -1 0 1 2 3 4-120-60

060

120Hendry 1990

-4 -3 -2 -1 0 1 2 3 4-120-60

060

120

Drift (%)

Paulay,et al. 1992

-4 -3 -2 -1 0 1 2 3 4-120-60

060


Drift (%)


-4 -3 -2 -1 0 1 2 3 4-120-60

060

120Holmes 1961

-4 -3 -2 -1 0 1 2 3 4-120-60

060

120Mainstone 1971

-4 -3 -2 -1 0 1 2 3 4-120-60

060

120

Base S

hear

(kN


-4 -3 -2 -1 0 1 2 3 4-120-60

060


-4 -3 -2 -1 0 1 2 3 4-120-60

060


-4 -3 -2 -1 0 1 2 3 4-120-60

060

120Hendry 1990

-4 -3 -2 -1 0 1 2 3 4-120-60

060

120

Drift (%)

Paulay,et al. 1992

-4 -3 -2 -1 0 1 2 3 4-120-60

060


Drift (%)


PhD 2016 | 9


Micro-modelling approach as a proxy for the experimental data

• The micro-modelling approach is as an effective tool to simulate the behaviour

masonry-infilled RC structures when experimental data is not available.

• Based on predefined and checked detailed micro-models, the structural parameters of

the strut were calibrated again.

Fully infilled specimens

- specimen M2

- specimen S

Partially infilled specimens

- specimen DO2

- specimen DX1

- specimen WO2

- specimen WX1

-6 -4 -2 0 2 4 6-150-75

075

150Holmes 1961

-6 -4 -2 0 2 4 6-150-75

075

150Mainstone 1971

-6 -4 -2 0 2 4 6-150-75

075

150

Base S

hear

(kN


-6 -4 -2 0 2 4 6-150-75

075


-6 -4 -2 0 2 4 6-150-75

075


-6 -4 -2 0 2 4 6-150-75

075

150Hendry 1990

-6 -4 -2 0 2 4 6-150-75

075

150

Drift (%)

Paulay,et al. 1992

-6 -4 -2 0 2 4 6-150-75

075


Drift (%)


-4 -3 -2 -1 0 1 2 3 4-120-60

060

120Holmes 1961

-4 -3 -2 -1 0 1 2 3 4-120-60

060

120Mainstone 1971

-4 -3 -2 -1 0 1 2 3 4-120-60

060

120

Base S

hear

(kN


-4 -3 -2 -1 0 1 2 3 4-120-60

060


-4 -3 -2 -1 0 1 2 3 4-120-60

060


-4 -3 -2 -1 0 1 2 3 4-120-60

060

120Hendry 1990

-4 -3 -2 -1 0 1 2 3 4-120-60

060

120

Drift (%)

Paulay,et al. 1992

-4 -3 -2 -1 0 1 2 3 4-120-60

060


Drift (%)


-4 -3 -2 -1 0 1 2 3 4-120-60

060

120Holmes 1961

-4 -3 -2 -1 0 1 2 3 4-120-60

060

120Mainstone 1971

-4 -3 -2 -1 0 1 2 3 4-120-60

060

120

Base S

hear

(kN


-4 -3 -2 -1 0 1 2 3 4-120-60

060


-4 -3 -2 -1 0 1 2 3 4-120-60

060


-4 -3 -2 -1 0 1 2 3 4-120-60

060

120Hendry 1990

-4 -3 -2 -1 0 1 2 3 4-120-60

060

120

Drift (%)

Paulay,et al. 1992

-4 -3 -2 -1 0 1 2 3 4-120-60

060


Drift (%)


-4 -3 -2 -1 0 1 2 3 4-120-60

060

120Holmes 1961

-4 -3 -2 -1 0 1 2 3 4-120-60

060

120Mainstone 1971

-4 -3 -2 -1 0 1 2 3 4-120-60

060

120

Base S

hear

(kN


-4 -3 -2 -1 0 1 2 3 4-120-60

060


-4 -3 -2 -1 0 1 2 3 4-120-60

060


-4 -3 -2 -1 0 1 2 3 4-120-60

060

120Hendry 1990

-4 -3 -2 -1 0 1 2 3 4-120-60

060

120

Drift (%)

Paulay,et al. 1992

-4 -3 -2 -1 0 1 2 3 4-120-60

060


Drift (%)


-4 -3 -2 -1 0 1 2 3 4-120-60

060

120Holmes 1961

-4 -3 -2 -1 0 1 2 3 4-120-60

060

120Mainstone 1971

-4 -3 -2 -1 0 1 2 3 4-120-60

060

120

Base S

hear

(kN


-4 -3 -2 -1 0 1 2 3 4-120-60

060


-4 -3 -2 -1 0 1 2 3 4-120-60

060


-4 -3 -2 -1 0 1 2 3 4-120-60

060

120Hendry 1990

-4 -3 -2 -1 0 1 2 3 4-120-60

060

120

Drift (%)

Paulay,et al. 1992

-4 -3 -2 -1 0 1 2 3 4-120-60

060


Drift (%)


-4 -3 -2 -1 0 1 2 3 4-120-60

060

120Holmes 1961

-4 -3 -2 -1 0 1 2 3 4-120-60

060

120Mainstone 1971

-4 -3 -2 -1 0 1 2 3 4-120-60

060

120

Base S

hear

(kN


-4 -3 -2 -1 0 1 2 3 4-120-60

060


-4 -3 -2 -1 0 1 2 3 4-120-60

060


-4 -3 -2 -1 0 1 2 3 4-120-60

060

120Hendry 1990

-4 -3 -2 -1 0 1 2 3 4-120-60

060

120

Drift (%)

Paulay,et al. 1992

-4 -3 -2 -1 0 1 2 3 4-120-60

060


Drift (%)


Conclusions

• The structural behaviour of the infill panel in masonry-infilled RC

structures can be presented by a single strut model.

• Calibration of the strut model parameters based on the strength

approach is more realistic when compared with the stiffness approach

• The experimentally-based calibration of the strut model parameters

minimizes the error in structural response when compared to strength or

stiffness approaches (which may lead to very large errors).

• The use of a micro-modelling approach as a proxy to the experimental

data to calibrate the strut parameters is able to represent the real

behaviour of the infill panel with a reasonable errors (the error of the

estimated initial stiffness and maximum force is less than 20%).

Modelling RC masonry infilled frames under earthquake loading:...

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