1. Y. S. Yang and S. H. Hsieh National Taiwan University, Taipei, Taiwan December 8, 2000 FE2000: An Object-Oriented Framework For Parallel Nonlinear Dynamic Finite Element Analysis

2. Develop a parallel FEA test bed –High performance –Parallel computing (substructure method) –Good extensibility & maintainability Introduction (1/2)

3. Introduction (2/2) FE2000 –Object oriented –Linear / Geometric nonlinear analysis –Static / Implicit dynamic analysis –Sequential / Parallel computing

4. Key classes (1/3) feAssemblage –Uses dynamic arrays for FE objects vector ANSI C++ Supported Useful for adaptive mesh refinement

5. Key classes (2/3) Hierarchy of feElement

6. Key classes (3/3) 2D-frame structure example

7. Substructure analysis Multi-level substructure hierarchy Iterative mesh partitioning approach –Improved Hsieh-Yang-Tsai (IHYT) approach for better computational load balance (Yang, 2000)

8. Matrix libraries (1/2) For solving [K]{d}={f} –Extended SPARSPAK (George and Liu, 1981) Direct, sequential Linear system solution/matrix condensation –SPOOLES (Ashcraft et al., 1999) Direct/Iterative, sequential/parallel –PETSc (Balay et al., 1997) Iterative, sequential/parallel

9. Matrix libraries (2/2) Interface between FE2000 and matrix libraries

10. Validation tests Static nonlinear analysis Dynamic analysis

11. Numerical experiments (1/2) Nonlinear dynamic analyses –Analysis methods Newmark method (avg. accel.) Total t = 0.2 sec., Δ t = 0.01 (20 time steps) Geometric nonlinearity Sequential / Parallel multi-level substructure method –Computing environment 4 PCs (Pentium II 350) + 100 Mbps network Linux Redhat FE2000 + Extended SPARSPAK

12. Numerical experiments (2/2) H5-12 11,568 BCs 25,344 DOFs O1-12 35,904 BCs 181,152 DOFs M12BD-2 4,032 B20s 64,809 DOFs B20P6416 2,048 BCs 34,767 DOFs S=2.89S=2.48S=3.60S=3.15

13. Conclusions & future works FE2000 –An efficient object-oriented parallel nonlinear dynamic FE package. Future works –More element types (plate, shell, etc.) –More material models –Adaptive mesh refinement –Pre/post processing