Current Search: Das, Partha S. (x)


Title

Redesign of JohnsonSeaLink acrylic submersible for manned operation to 3000 ft (914.4 m) ocean depth.

Creator

Das, Partha S.

Date Issued

200004

PURL

http://purl.flvc.org/fcla/dt/3359266

Subject Headings

JohnsonSeaLink II (Submarine), Submersibles, SubmersiblesDesign and construction

Format

Document (PDF)


Title

Detailed stress analysis of a spherical acrylic submersible by 3D finite element modeling.

Creator

Das, Partha S., Harbor Branch Oceanographic Institute

Date Issued

1999

PURL

http://purl.flvc.org/fau/fd/FA00007504

Subject Headings

Pressure vessels, Finite element method, Pressure vesselsCracking

Format

Document (PDF)


Title

A 3D laser line scanner for outcrop scale studies of seafloor features.

Creator

Kocak, D. M., Caimi, F. M., Das, Partha S., Karson, J. A., Harbor Branch Oceanographic Institute

Date Issued

1999

PURL

http://purl.flvc.org/FCLA/DT/3351977

Subject Headings

Scanning systems, CartographyLaser use in, Geological maps, Submersibles, Ocean bottomMaps

Format

Document (PDF)


Title

Evolution and application of a parallel algorithm for explicit transient finite element analysis on SIMD/MIMD computers.

Creator

Das, Partha S., Florida Atlantic University, Case, Robert O., Tsai, ChiTay, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering

Abstract/Description

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...
Show moreThe 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.
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Date Issued

1997

PURL

http://purl.flvc.org/fcla/dt/12500

Subject Headings

Finite element method, Algorithms, Parallel computers

Format

Document (PDF)