• Version
• 146 Downloads
• 7.18 MB File Size
• 1 File Count
• March 5, 2017 Create Date
• March 5, 2017 Last Updated

Numerical Analysis of Laminated, Orthotropic Composite Structures

During the first part of this investigatim two finite-element 
were developedl.2 for the purpose of malysis of laminar. orthotropic struc- 
tures in the forn of bodies of revolution. mdels al IN for orthotropic 
axes to be a±itrarily oriented with respect to the cylindrical coordinates. 
Because of this, the models allow for three COQcnents of displacements in- 
eluding the tH0 cnponents in the æridian plane md the circumferential com- 
ponent. As a result, the be used to malyze unbalanced laminar 
configurations ud stresses can be predicted. The two Ndels 
have been developed differ in the basic finite-element shape which 
was used. The shape is defined by the cross-section Of the eleænts in the 
xridim plute. 
In the first Ndell, a nine degree-of-freedom, straight sided, tri- 
mgular elexnt was used. In this elexnt, the three cmponents of dis- 
placernt are defined at eaå comer of the trimgle md a linear displace- 
variation is assurd inside the eleznt. In the second Nde12, a 
hiØ1er order, isoparaNtric elenent was used with quadratic displacxnt 
variations for two of the *Tidian displacernts md a linear variation 
for the circtnferential coponent. These elemnts are triangular with 
curved sides md mid-side nodes in additim to the comer nodes. 
of these elements possesses fifteen degrees-of-freedom. 
A nt*er of m=rical exaQles were analyzed with both of Chese 
mdels to check-out the *thods md the associated coquter progrns. One 
of these exuples was malyzed by both nodels md was intended to coQare 
the relative accuracy Of *thod. It was fowtd that, for en equivalent 
of total degrees-of-freedom. the results given by both *thods were 
very close2. AlthouØ1 the total Of degrees-of-freedom in both Mdels 
was the sau, fewer of the isoparuetric eleynts had to be used. The con- 
elusion fron this study was that eaå of these mdels was equally accurate 
md either me could be used for any given problem.