Transcript Diapositiva 1

The Fourteenth International Conference on Civil, Structural and Environmental Engineering Computing
3-6 September 2013
Cagliari, Sardinia, Italy
Enhanced Mesoscale Partitioned Modelling
for Unreinforced Masonry Structures
L. Macorini - B.A. Izzuddin
Computational Structural Mechanics Group
Department of Civil and Environmental Engineering
Imperial College London, UK
Outline
Advanced modelling for URM
Mesoscale Partitioned Modelling
3D Mesoscale model
Domain Partitioning approach
Enhancements to improve efficiency
Conclusions
Enhanced Mesoscale Partitioned Modelling for Unreinforced Masonry Structures
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Advanced modelling for URM
• Mesoscale descriptions for URM guarantee
accurate response prediction
Mesoscale model
Two-material approach
Mesoscale
scale
• Detailed mesoscale models are usually
computationally demanding
(Massart, 2007)
Enhanced Mesoscale Partitioned Modelling for Unreinforced Masonry Structures
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Mesoscale Partitioned Modelling
An advanced 3D mesoscale model is combined with partitioning approach
Structural scale
• Partitioning
Solid elements and 2D
nonlinear interfaces
approach with super-elements for masonry
• Parallel computing
Enhanced Mesoscale Partitioned Modelling for Unreinforced Masonry Structures
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3D mesoscale model for nonlinear analysis under extreme loading
2D nonlinear interface element
C
• Multi-surface nonassociated
plasticity
s
sst
s
s<0
s
sc t
t
s
• Geometric nonlinearity
Compression test
Shear test
GG
f,IIf,I
Enhanced Mesoscale Partitioned Modelling for Unreinforced Masonry Structures
stanf
Gc
uz
s
uux(y)
z
t
ss
4/28
3D mesoscale model for nonlinear analysis under extreme loading
In-plane behaviour
Vermeltfoort AT, Raijmakers TMJ (1993)
mortar
interface
pv=0.3 MPa
brick
interface
mortar interface
J4D
J5D
Enhanced Mesoscale Partitioned Modelling for Unreinforced Masonry Structures
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3D mesoscale model for nonlinear analysis under extreme loading
In-plane behaviour
Vermeltfoort AT, Raijmakers TMJ (1993)
Wpl1
Wpl1
Wpl1
Wpl1
pv=0.3 MPa
Wpl2
J4D
J5D
Enhanced Mesoscale Partitioned Modelling for Unreinforced Masonry Structures
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3D mesoscale model for nonlinear analysis under extreme loading
In-plane behaviour
Vermeltfoort AT, Raijmakers TMJ (1993)
Wpl1
Wpl2
Nonlinear Analysis of Masonry Structures using Mesoscale Partitioned Modelling
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3D mesoscale model for nonlinear analysis under extreme loading
Out-of-plane behaviour
Chee Liang, N.G. (1996)
Wpl1
Nonlinear Analysis of Masonry Structures using Mesoscale Partitioned Modelling
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3D mesoscale model for nonlinear analysis under extreme loading
Mesoscale analysis of large URM components
Gattesco et al. (2008)
Enhanced Mesoscale Partitioned Modelling for Unreinforced Masonry Structures
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3D mesoscale model for nonlinear analysis under extreme loading
Mesoscale analysis to represent
quasi-brittle behaviour
A)
B)
• Dynamic analyses with a large number
of time steps are used for representing
post-peak response
Enhanced Mesoscale Partitioned Modelling for Unreinforced Masonry Structures
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Domain partitioning approach
Enhanced Mesoscale Partitioned Modelling for Unreinforced Masonry Structures
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Domain partitioning approach
MPI
Communication between parent structure and partitions
Enhanced Mesoscale Partitioned Modelling for Unreinforced Masonry Structures
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Domain partitioning approach
Detailed analysis of large structures
162840 nodes – 62 partitions
sm [MPa]
Enhanced Mesoscale Partitioned Modelling for Unreinforced Masonry Structures
W pl1m [MPa]
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Domain partitioning approach
Detailed analysis of large structures
162840 nodes
62 partitions
• When
analysing large URM structures, the most critical
process becomes that of the parent structure. This may
significantly reduce efficiency leading to an excessively long
wall-clock time.
Enhanced Mesoscale Partitioned Modelling for Unreinforced Masonry Structures
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Domain partitioning approach
Detailed analysis of large structures
162840 nodes
62 partitions
• Enhancements to improve efficiency:
- Hierarchic partitioning
- Mixed-dimensional coupling
Enhanced Mesoscale Partitioned Modelling for Unreinforced Masonry Structures
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Enhanced domain partitioning approach
Enhancements to improve efficiency
• Modelling with hierarchic partitioning
Enhanced Mesoscale Partitioned Modelling for Unreinforced Masonry Structures
(Jokhio 2012)
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Enhanced domain partitioning approach
Enhancements to improve efficiency
• Modelling with partitions and master-slave coupling (Jokhio 2012)
Mixed-dimensional
coupling
6 DoF
Enhanced Mesoscale Partitioned Modelling for Unreinforced Masonry Structures
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Enhanced domain partitioning approach
Enhancements to improve efficiency
• Modelling heterogeneous structures with URM
Infilled frame
Elasto-plastic beam elements are used for modelling beams and columns of the
frame, while the detailed mesoscale description is utilised for URM panels
Enhanced Mesoscale Partitioned Modelling for Unreinforced Masonry Structures
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Enhanced domain partitioning approach
Numerical examples
• Numerical performance (Speed-up)
uz
ux
Elastic analysis of a large URM wall
(48  48 20-noded solid elements)
Prescribed top vertical displacements in 1 step
and top horizontal displacements in 10 steps
Enhanced Mesoscale Partitioned Modelling for Unreinforced Masonry Structures
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Enhanced domain partitioning approach
Numerical examples
• Numerical performance (Speed-up)
P-L1
P-L2
Standard (flat) Partitioning
Approach
Enhanced Partitioning Approach
(hierarchic partitioning)
Elastic analysis of a large URM wall (48  48 20-noded solid elements)
Enhanced Mesoscale Partitioned Modelling for Unreinforced Masonry Structures
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Enhanced domain partitioning approach
Numerical examples
• Numerical performance – Speed-up
model
N.
processors
Parent Struct.
DOFs
Part. L1
DOFs
Part. L2
DOFs
S
m
P4
P16
P64
P4 mslc
P16 mslc
P64 mslc
P44
1
5
17
65
5
17
65
20
142848
2304
6912
16128
576
1728
4032
768
36864
9792
2736
36864
9792
2736
2304
9792
4.60
6.96
3.24
3.73
12.43
116.39
14.40
P416
P44 mslc
69
20
768
96
2304
576
2736
9792
28.65
17.63
P4x16 mslc
69
96
576
2736
205.50
Si= Tm/TSi
Tm = 13152 s
flat partitioning
Elastic analysis of a large URM wall (48  48 20-noded solid elements)
Enhanced Mesoscale Partitioned Modelling for Unreinforced Masonry Structures
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Enhanced domain partitioning approach
Numerical examples
• Numerical performance – Speed-up
8
P-L1
7
Si= Tm/TSi
Tm = 13152 s
Speed-up S
6
5
4
3
2
1
Flat partitioning
0
0
10
20
30
40
50
60
70
N. of processors
Elastic analysis of a large URM wall (48  48 20-noded solid elements)
Enhanced Mesoscale Partitioned Modelling for Unreinforced Masonry Structures
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Enhanced domain partitioning approach
Numerical examples
• Numerical performance – Speed-up
model
N.
processors
Parent Struct.
DOFs
Part. L1
DOFs
Part. L2
DOFs
S
m
P4
P16
P64
P4 mslc
P16 mslc
P64 mslc
P44
1
5
17
65
5
17
65
20
142848
2304
6912
16128
576
1728
4032
768
36864
9792
2736
36864
9792
2736
2304
9792
4.60
6.96
3.24
3.73
12.43
116.39
14.40
P416
P44 mslc
69
20
768
96
2304
576
2736
9792
28.65
17.63
P4x16 mslc
69
96
576
2736
205.50
Si= Tm/TSi
Tm = 13152 s
flat partitioning with
mixed-dimensional
coupling
hierarchic
hierarchic
partitioning
partitioning with
mixed-dimensional
coupling
Elastic analysis of a large URM wall (48  48 20-noded solid elements)
Enhanced Mesoscale Partitioned Modelling for Unreinforced Masonry Structures
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Enhanced domain partitioning approach
Enhancements to improve efficiency
• Numerical performance – Speed-up
Si= Tm/TSi
Tm = 13152 s
Elastic analysis of a large URM wall (48  48 20-noded solid elements)
Enhanced Mesoscale Partitioned Modelling for Unreinforced Masonry Structures
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Enhanced domain partitioning approach
Enhancements to improve efficiency
• Solution accuracy: partitioned vs. monolithic model
Normal stresses after the application of the vertical displacement
Enhanced Mesoscale Partitioned Modelling for Unreinforced Masonry Structures
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Enhanced domain partitioning approach
Enhancements to improve efficiency
• Solution accuracy: partitioned vs. monolithic model
Normal stresses at the end of the analysis
Enhanced Mesoscale Partitioned Modelling for Unreinforced Masonry Structures
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Enhanced domain partitioning approach
Numerical examples
• Analysis of heterogeneous structures under extreme loading
Enhanced Mesoscale Partitioned Modelling for Unreinforced Masonry Structures
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Enhanced domain partitioning approach
Numerical examples
• Analysis of heterogeneous structures under extreme loading
Model validation under blast loading (Macorini and Izzuddin 2013)
Blast pressure in time
Enhanced Mesoscale Partitioned Modelling for Unreinforced Masonry Structures
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Enhanced domain partitioning approach
Numerical examples
• Analysis of heterogeneous structures under extreme loading
Enhanced Mesoscale Partitioned Modelling for Unreinforced Masonry Structures
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Conclusions
When using hierarchic partitioning and master-slave
coupling, contrary to the case of flat partitioning,
computational efficiency is preserved also in the analysis
of URM structures modelled using a large number of
partitions
In the case of master-slave coupling the gain in
computational performance is obtained losing accuracy
depending upon the specific loading conditions
This limitation will be overcome in next enhancements
by introducing soft coupling using a Lagrangian
multiplier approach
Enhanced Mesoscale Partitioned Modelling for Unreinforced Masonry Structures
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Acknowledgements
The authors gratefully acknowledge the High Performance
Computing (HPC) Services at Imperial College London for providing
and supporting the required computing facilities.
Enhanced Mesoscale Partitioned Modelling for Unreinforced Masonry Structures