A NASTRAN DMAP ALTER FOR LINEAR BUCKLING ANALYSIS UNDER DYNAMIC LOADING Author : Robert A. Aiello and Joseph E. Grady

WHAT IS THIS DOCUMENT ABOUT? : A unique modification to the NASTRAN solution sequence for transient analysis with direct time integration (COSMIC NASTRAN rigid format) has been developed and incorporated into a DMAP alter. This DMAP alter calculates the buckling stability of a dynamically loaded structure, and is used to predict the onset of structural buckling under stress-wave loading conditions. The modified solution sequence incorporates the linear buckling analysis capability (rigid format) of NASTRAN into the existing Transient solution rigid format in such a way as to provide a time dependent eigensolution which is used to assess the buckling stability of the structure as it responds to the impulsive load. As a demonstration of the validity of this modlfied solution procedure, the dynamic buckling of a prismatic bar subjected to an impulsive longitudinal compression is analyzed and compared to the known theoretical solution. In addition, a dynamic buckling analysis is performed for the analytically less tractable problem of the localized dynamic buckling of an initially flawed composite laminate under transverse impact loading. The addition of this DMAP alter to the transient solution sequence in NASTRAN facilitates the computational prediction of both the time at which the onset of dynamic buckling occurs in an impulsively loaded structure, and the dynamic buckling mod

Keywords	:	nastran dmap linear buckling dynamic loading
file credit	:	Robert A. Aiello and Joseph E. Grady
file type	:	pdf
file topic	:	Engineering
rating	:	Loading ...
viewed	:	327 times
file address	:	ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19890004151_1989004151.pdf

pdf preview: