Engineering topics

Mitchell, R. S.

Publications and source records attributed to Mitchell, R. S..

2 records

NASA NTRS1985

Improved accuracy in solid isoparametric elements using selectively reduced integration

Currently COSMIC NASTRAN uses the same Gaussian integration order for every term in the stiffness matrix of the solid isoparametric elements. This results in overly stiff elements under some conditions. A modification to the CIHEXI, CIHEX2 and CIHEX3 elements is described which provides the user with the capability of controlling the order of integration for selected terms in the stiffness matrix. Examples of improved accuracy using selectively reduced integration be provided are provided.

Case, W. R.↗

NASA NTRS1977

Software for transferring NASTRAN datablocks between dissimilar computers

Efforts to freely exchange all types of NASTRAN datablocks between the internalized forms in any of three makes of NASTRAN-class computers and that of any other such make are described. The medium used is magnetic tape formatted in BCD (Binary Coded Decimal) character and numerical fields. The method used involves a FORTRAN-coded post-processor and a pre-processor, mostly portable but with a small assembly-coded component peculiar to each make of machine. Snags in a method reported in an earlier NASTRAN colloquium have been overcome and functional requirements upgraded as well.

Rosencranz, R.↗