The Finite Element Machine (FEM) was a late 1970s-early 1980s NASA project to build and evaluate the performance of a parallel computer for

structural analysis Structural analysis is a branch of Solid Mechanics which uses simplified models for solids like bars, beams and shells for engineering decision making. Its main objective is to determine the effect of loads on the physical structures and thei ...

. The FEM was completed and successfully tested at the NASA Langley Research Center in

Hampton, Virginia Hampton () is an independent city (United States), independent city in the Commonwealth (U.S. state), Commonwealth of Virginia in the United States. As of the 2020 United States Census, 2020 census, the population was 137,148. It is the List ...

. The motivation for FEM arose from the merger of two concepts: the finite element method of

and the introduction of relatively low-cost microprocessors. In the finite element method, the behavior (stresses, strains and displacements resulting from load conditions) of large-scale structures is

approximate An approximation is anything that is intentionally similar but not exactly equal to something else. Etymology and usage The word ''approximation'' is derived from Latin ''approximatus'', from ''proximus'' meaning ''very near'' and the prefix ' ...

d by a FE model consisting of structural elements (members) connected at structural node points. Calculations on traditional computers are performed at each node point and results communicated to adjacent node points until the behavior of the entire structure is computed. On the Finite Element Machine, microprocessors located at each node point perform these nodal computations in parallel. If there are more node points (N) than microprocessors (P), then each microprocessor performs N/P computations. The Finite Element Machine contained 32 processor boards each with a Texas Instruments TMS9900 processor, 32 Input/Output (IO) boards and a TMS99/4 controller. The FEM was conceived, designed and fabricated at NASA Langley Research Center. The TI 9900 processor chip was selected by the NASA team as it was the first 16-bit processor available on the market which until then was limited to less powerful

8-bit In computer architecture, 8-bit Integer (computer science), integers or other Data (computing), data units are those that are 8 bits wide (1 octet (computing), octet). Also, 8-bit central processing unit (CPU) and arithmetic logic unit (ALU) arc ...

processors. The FEM concept was first successfully tested to solve beam bending equations on a Langley FEM

prototype A prototype is an early sample, model, or release of a product built to test a concept or process. It is a term used in a variety of contexts, including semantics, design, electronics, and Software prototyping, software programming. A prototyp ...

( 4 IMSAI 8080s). This led to full-scale FEM fabrication & testing by the FEM hardware-software-applications team led by Dr.

Olaf Storaasli Olaf O. StoraasliSynective LabsVP, was a researcher at Oak Ridge National Laboratory (Computer Science and Mathematics Division'Future Technologies Group and USEC following his NASA Langley Research Center, NASA career. He led the hardware, soft ...

formerly of NASA Langley Research Center and Oak Ridge National Laboratory (currently at USEC). The first significant Finite Element Machine results are documented in: The Finite Element Machine: An experiment in parallel processing (NASA TM 84514). Based on the Finite Element Machine's success in demonstrating Parallel Computing viability, (alongside ILLIAC IV and Goodyear MPP), commercial parallel computers soon were sold. NASA Langley subsequently purchased a Flex/32 Multicomputer (and later Intel iPSC and

Intel Paragon The Intel Paragon is a discontinued series of massively parallel supercomputers that was produced by Intel in the 1990s. The Paragon XP/S is a productized version of the experimental ''Touchstone Delta'' system that was built at Caltech, launched ...

) to continue parallel finite element algorithm R&D. In 1989, the parallel equation solver code, first prototyped on FEM, and tested on FLEX was ported to NASA's first Cray YMP via Force (Fortran for Concurrent Execution) to reduce the structural analysis computation time for the space shuttle Challenger Solid Rocket Booster resdesign with 54,870 equations from 14 hours to 6 seconds. This research accomplishment was awarded the first Cray GigaFLOP Performance Award at Supercomputing '89. This code evolved into NASA's General-Purpose Solver (GPS) for Matrix Equations used in numerous finite element codes to speed solution time. GPS sped up AlphaStar Corporation's Genoa code 10X, allowing 10X larger applications for which the team received NASA's 1999 Software of the Year Award and a 2000 R&D100 Award.

References

{{Cite report , author = Harry F. Jordan , year = 1986 , title = The Force on the Flex: global parallelism and portability , url = http://apps.dtic.mil/dtic/tr/fulltext/u2/a211391.pdf , archive-url = https://web.archive.org/web/20160605040158/http://www.dtic.mil/dtic/tr/fulltext/u2/a211391.pdf , url-status = live , archive-date = June 5, 2016 , publisher = NASA , accessdate = May 9, 2016 ;Further reading
System software for the finite element machine

PASLIB programmer's guide for the finite element machine, revision 2.1-A

Operating systems support for the finite element machineThree Parallel Computation Methods for Structural Vibration Analysis

Solution of Structural Analysis Problems on a Parallel Computer

Structural Dynamic Analysis on a Parallel Computer: The Finite Element Machine

References

See also