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3-6 September 2013 Cagliari, Sardinia, Italy. Enhanced Mesoscale Partitioned Modelling for Unreinforced Masonry Structures. L. Macorini - B.A. Izzuddin. The Fourteenth International Conference on Civil, Structural and Environmental Engineering Computing.
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3-6 September 2013 Cagliari, Sardinia, Italy Enhanced Mesoscale Partitioned Modelling for Unreinforced Masonry Structures L. Macorini - B.A. Izzuddin The Fourteenth International Conference on Civil, Structural and Environmental Engineering Computing 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 1/28
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 2/28
Mesoscale Partitioned Modelling An advanced 3D mesoscale model is combined with partitioning approach • Solid elements and 2D nonlinear interfaces • Structural scale • Partitioning approach with super-elements for masonry • Parallel computing Enhanced Mesoscale Partitioned Modelling for Unreinforced Masonry Structures 3/28
2D nonlinear interface element s C s • st s • Gf,I s s • uz • sc 3D mesoscale model for nonlinear analysis under extreme loading • Multi-surface nonassociated • plasticity • Geometric nonlinearity s t • Gc t • s<0 s • uz Compression test t • stanf • Gf,II s Shear test • ux(y) Enhanced Mesoscale Partitioned Modelling for Unreinforced Masonry Structures 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 5/28
In-plane behaviour Vermeltfoort AT, Raijmakers TMJ (1993) Wpl1 Wpl1 pv=0.3 MPa Wpl1 Wpl1 Wpl2 3D mesoscale model for nonlinear analysis under extreme loading J4D J5D Enhanced Mesoscale Partitioned Modelling for Unreinforced Masonry Structures 6/28
In-plane behaviour Vermeltfoort AT, Raijmakers TMJ (1993) Wpl1 3D mesoscale model for nonlinear analysis under extreme loading Wpl2 Nonlinear Analysis of Masonry Structures using Mesoscale Partitioned Modelling 7/28
Out-of-plane behaviour Chee Liang, N.G. (1996) 3D mesoscale model for nonlinear analysis under extreme loading Wpl1 Wpl1 Wpl1 Nonlinear Analysis of Masonry Structures using Mesoscale Partitioned Modelling 8/28
Mesoscale analysis of large URM components Gattesco et al. (2008) 3D mesoscale model for nonlinear analysis under extreme loading Enhanced Mesoscale Partitioned Modelling for Unreinforced Masonry Structures 9/28
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 10/28
Domain partitioning approach Enhanced Mesoscale Partitioned Modelling for Unreinforced Masonry Structures 11/28
Domain partitioning approach MPI Communication between parent structure and partitions Enhanced Mesoscale Partitioned Modelling for Unreinforced Masonry Structures 12/28
Domain partitioning approach Detailed analysis of large structures 162840 nodes – 62 partitions sm [MPa] Wpl1m[MPa] Enhanced Mesoscale Partitioned Modelling for Unreinforced Masonry Structures 13/28
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 14/28
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 15/28
Enhanced domain partitioning approach Enhancements to improve efficiency • Modelling with hierarchic partitioning (Jokhio 2012) Enhanced Mesoscale Partitioned Modelling for Unreinforced Masonry Structures 16/28
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 17/28
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 18/28
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 19/28
Enhanced domain partitioning approach Numerical examples • Numerical performance (Speed-up) Standard (flat) Partitioning Approach P-L1 Enhanced Partitioning Approach (hierarchic partitioning) P-L2 Elastic analysis of a large URM wall (48 48 20-noded solid elements) Enhanced Mesoscale Partitioned Modelling for Unreinforced Masonry Structures 20/28
Enhanced domain partitioning approach Numerical examples • Numerical performance – Speed-up 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 21/28
Enhanced domain partitioning approach Numerical examples • Numerical performance – Speed-up 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 22/28
Enhanced domain partitioning approach Numerical examples • Numerical performance – Speed-up Si= Tm/TSi Tm = 13152 s flat partitioning with mixed-dimensional coupling hierarchic partitioning hierarchic 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 21/28
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 23/28
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 24/28
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 24/28
Enhanced domain partitioning approach Numerical examples • Analysis of heterogeneous structures under extreme loading Enhanced Mesoscale Partitioned Modelling for Unreinforced Masonry Structures 25/28
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 26/28
Enhanced domain partitioning approach Numerical examples • Analysis of heterogeneous structures under extreme loading Enhanced Mesoscale Partitioned Modelling for Unreinforced Masonry Structures 27/28
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 28/28
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