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Evolution and application of a parallel algorithm for explicit transient finite element analysis on SIMD/MIMD computers
 Date Issued:
 1997
 Summary:
 The development of a parallel data structure and an associated elemental decomposition algorithm for explicit finite element analysis for massively parallel SIMD computer, the DECmpp 12000 (MasPar MP1) machine, is presented, and then extended to implementation on the MIMD computer, CrayT3D. The new parallel data structure and elemental decomposition algorithm are discussed in detail and is used to parallelize a sequential Fortran code that deals with the application of isoparametric elements for the nonlinear dynamic analysis of shells of revolution. The parallel algorithm required the development of a new procedure, called an 'exchange', which consists of an exchange of nodal forces at each time step to replace the standard gatherassembly operations in sequential code. In addition, the data was reconfigured so that all nodal variables associated with an element are stored in a processor along with other element data. The architectural and Fortran programming language features of the MasPar MP1 and CrayT3D computers which are pertinent to finite element computations are also summarized, and sample code segments are provided to illustrate programming in a data parallel environment. The governing equations, the finite element discretization and a comparison between their implementation on Von Neumann and SIMDMIMD parallel computers are discussed to demonstrate their applicability and the important differences in the new algorithm. Various large scale transient problems are solved using the parallel data structure and elemental decomposition algorithm and measured performances are presented and analyzed in detail. Results show that CrayT3D is a very promising parallel computer for finite element computation. The 32 processors of this machine shows an overall speedup of 2728, i.e. an efficiency of 85% or more and 128 processors shows a speedup of 7077, i.e. an efficiency of 55% or more. The CrayT3D results demonstrated that this machine is capable of outperforming the CrayYMP by a factor of about 10 for finite element problems with 4K elements, therefore, the method of developing the parallel data structure and its associated elemental decomposition algorithm is recommended for implementation on other finite element code in this machine. However, the results from MasPar MP1 show that this new algorithm for explicit finite element computations do not produce very efficient parallel code on this computer and therefore, the new data structure is not recommended for further use on this MasPar machine.
Title:  Evolution and application of a parallel algorithm for explicit transient finite element analysis on SIMD/MIMD computers. 
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Name(s): 
Das, Partha S. Florida Atlantic University, Degree grantor Case, Robert O., Thesis advisor Tsai, ChiTay, Thesis advisor College of Engineering and Computer Science Department of Ocean and Mechanical Engineering 

Type of Resource:  text  
Genre:  Electronic Thesis Or Dissertation  
Issuance:  monographic  
Date Issued:  1997  
Publisher:  Florida Atlantic University  
Place of Publication:  Boca Raton, Fla.  
Physical Form:  application/pdf  
Extent:  259 p.  
Language(s):  English  
Summary:  The development of a parallel data structure and an associated elemental decomposition algorithm for explicit finite element analysis for massively parallel SIMD computer, the DECmpp 12000 (MasPar MP1) machine, is presented, and then extended to implementation on the MIMD computer, CrayT3D. The new parallel data structure and elemental decomposition algorithm are discussed in detail and is used to parallelize a sequential Fortran code that deals with the application of isoparametric elements for the nonlinear dynamic analysis of shells of revolution. The parallel algorithm required the development of a new procedure, called an 'exchange', which consists of an exchange of nodal forces at each time step to replace the standard gatherassembly operations in sequential code. In addition, the data was reconfigured so that all nodal variables associated with an element are stored in a processor along with other element data. The architectural and Fortran programming language features of the MasPar MP1 and CrayT3D computers which are pertinent to finite element computations are also summarized, and sample code segments are provided to illustrate programming in a data parallel environment. The governing equations, the finite element discretization and a comparison between their implementation on Von Neumann and SIMDMIMD parallel computers are discussed to demonstrate their applicability and the important differences in the new algorithm. Various large scale transient problems are solved using the parallel data structure and elemental decomposition algorithm and measured performances are presented and analyzed in detail. Results show that CrayT3D is a very promising parallel computer for finite element computation. The 32 processors of this machine shows an overall speedup of 2728, i.e. an efficiency of 85% or more and 128 processors shows a speedup of 7077, i.e. an efficiency of 55% or more. The CrayT3D results demonstrated that this machine is capable of outperforming the CrayYMP by a factor of about 10 for finite element problems with 4K elements, therefore, the method of developing the parallel data structure and its associated elemental decomposition algorithm is recommended for implementation on other finite element code in this machine. However, the results from MasPar MP1 show that this new algorithm for explicit finite element computations do not produce very efficient parallel code on this computer and therefore, the new data structure is not recommended for further use on this MasPar machine.  
Identifier:  9780591305913 (isbn), 12500 (digitool), FADT12500 (IID), fau:9392 (fedora)  
Collection:  FAU Electronic Theses and Dissertations Collection  
Note(s): 
College of Engineering and Computer Science Thesis (Ph.D.)Florida Atlantic University, 1997. 

Subject(s): 
Finite element method Algorithms Parallel computers 

Held by:  Florida Atlantic University Libraries  
Persistent Link to This Record:  http://purl.flvc.org/fcla/dt/12500  
Sublocation:  Digital Library  
Use and Reproduction:  Copyright © is held by the author, with permission granted to Florida Atlantic University to digitize, archive and distribute this item for nonprofit research and educational purposes. Any reuse of this item in excess of fair use or other copyright exemptions requires permission of the copyright holder.  
Use and Reproduction:  http://rightsstatements.org/vocab/InC/1.0/  
Host Institution:  FAU  
Is Part of Series:  Florida Atlantic University Digital Library Collections. 