A procedure is presented for obtaining contour plots of any physical quantity defined on a number of points of the surface of a structure. Rigid Format 1 of HEAT approach in Cosmic NASTRAN is ALTERED to enable use of contour plotting capability for scalar quantities. The ALTERED DMAP sequence is given. Examples include temperature distribution on the face of a cooled laser mirror and the angle of incidence or a radome surface

Gallo, M.

Mittal, S.

Wang, T.

English

NASA Technical Reports Server

A N  TJNUSUAL APPLICATION OF NASTRAN CONTOUR 
PLOTTING CAPABILITY 
S. Mit ta l ,  k!. G a l l o  and T. Wang 
BELL AERgSPACE TEXTRON 
A s imple  p rocedure  t o  o b t a i n  con tour  p l o t s  of any physic11 q u a n c i t y  d e f i n e d  on 
a  number of p o i n t s  of t h e  s u r f a c e  of a  s t r u c t u r e  i s  p r d s e n t e d .  R ig id  Format 1 of 
HEAT approach ir  Cosjnic NAST2AN i s  ALTERED t o  e n a b l e  u s e  of con tour  p l o t t i n g  capa-  
b i l i t y  f o r  s c a l a r  q u a n t i t i e s .  ALTERED D F W  sequrnce  and exzmples a r e  i n c l u d e d .  
INTRODUCTION 
I n  many e n g i n e e r i n g  s i . tuat i0n.s  e i t h e r  a  u s e r  h a s  t h e  need f o r  v i s ~ ! d l  v e r i i i c a -  
t i o n  of t h e  i n p u t  d a t a  f o r  s t r u c t u r a l  a n a l y s i s ,  e . g . ,  t empera tu re  d i s t r i h u t i o n  f o r  
the rmal  s t r e s s  a n a l y s i s  i n  h e a t  exchangers  o r  might  wish  t o  o b t a i n  c o n t o u r  p l o t s  of 
a  n o n s t r u c t u r a l  e n g i n e e r i n g  q u a n t i t y  l i k e  f l u x  o r  a n g l e s  of i n c i d e n c e ,  e t c .  Most 
o f t t n ,  a  d e t a i l e d  s t r u c t u r a l  a n a l y s i s  of t h e  same p i e c e  of t h e  hardware i s  a l s o  re- 
q u i r e d ,  f o r  which a  NASTRAN f l n i t e  e l e m e r t  model i s  a l r e a d y  a v a i l a b l e .  I n  such  
s i t u a t i o n s ,  t h e  concour p l o t t i n g  c a p a b i l i t y  i n  NASTRAN c a n  be v e r y  c o n v e n i e n t l y  used 
t o  g e n e r a t e  d e s i r e d  p l a t s .  I n  KASTRAN con tour  p l o t s  can  a n l y  be o b t a i n e d  f o r  s u r -  
f a c e s  t h a t  have 2-dimensional e lements .  However, f  o r  model- w i t h  s o l i d  e lements  
o n l y ,  dummy l a y e r s  of v e r y  t h i n  p l a t e  e l e m e n t s  have been used t o  s u c c e s s f u l l y  draw 
con tour  p l o t s  even i n  t h e  i n t e r i o r  of t h e  s t r u c t u r e .  
Heat anproach,  s o l u t i o n  1 i n  COSMIC NASTRAPJ i s  p r e f e r r e d  :or t h i s  a p n l i c a t i o n  
because i t  p e r m i t s  d e f i n i n g  a  s c a l a r  q u a n t i t y  a t  a  g r i d  p o i n t  and ma' .e t h e  d a t a  
p r e p a r a t i o n  e a s i e r .  P rocedure  i s  i n e x p e n s i v e  because a lmos t  a l l  :hr s o l u t i o n  s t e p s  
i n  t h e  R i g i d  Format a r e  sk ipped  and o n l y  t h e  p l o t t i n g  c a p a b i l i t y  1s r a d e  u s e  o f .  
The a p p l i c a t i o n  of t h e  p r e s e n t e d  t echn ique  r e q u i r e s ,  f o r  l a r g e  problems,  some 
a d d i t i o n a l  computer programming e f f o r t  where g r i d  p o i n t  d e f i n i t i o n  d a t a  i s  r e a d  from 
a  NASTXAN deck ,  the  p h y s i c a l  q u a n t i t y  i s  computed on t h e  c o o r d i n a t e s  of g r i d  p o i n t s  
and t h e  r e s u l t s  a r e  w r i t t e n  o u t  on NASTRAN f o r m a t t e d  SPC c a r d s .  A l t e r n a t i v e l y ,  f o r  
s m a l l  problems,  t h i s  d a t a  can be manual ly  i n p u t  on hPSTRAN c a r d s .  
CONTOUF PLOTTING PROCEDURE 
To o b t a i n  con tour  p l o t s ,  a  r e g u l a r  NASTRAN r u n  w i t h  DMAP a l t e r s ,  p r e s e n t e d  i n  
Appendix A a s  p a r t  of a  sample e x e c u t i v e  deck ,  i s  r e q u i r e d  t o  be s u b m i t t e d .  Normal 
in l -u t  d a t a  p r o c e s s i n g  f o r  geometry d e f i n i t i o n  i n  terms of G R I D  and e lement  connec- 
t i o n  c a r d s  and p l o t  s e t  d e f i n i t i o n s  i s  done a s  b s u a l .  
https://ntrs.nasa.gov/search.jsp?R=19850017561 2020-03-22T19:18:23+00:00Z
The p h v s i c s l  q u a n t i t y  must be def ined  a s  enforce.  . .:olacement 
SPC ca rds  f o r  each g r i d  p o i n t .  The m t i r e  s o l u t i o n  sequence i s  ski?p. d  and a n  equiv-  
a lence  's made between t he  s i n g l e  p o i n t  c o n s t r a i n t  set(Us)  and t i e  s t , u c t u r a l  s e t  
(Ug) ( ~ e f e r e r c e  i). This  s t e p  r e d e f i n e s  t h e  i n p u t  a s  output  s r  - *3t the  output  
Ivector  can now be processed t o  genera te  p l o t s .  Once the user  nc s  t he  SPS ca rds  
t he  r e s t  of t he  procedure i s  automatic .  
The ca se  c o n t r o l  deck conz iscs  of t he  s e l e c t i o n  of SPC s e t  and p r in t i i l g  o u t ,  i f  
d e s i r e d ,  of tile phys i ca l  q u a n t i t y  a s  temperature.  The   lotting i t s e l f  i s  requested 
v i a  r e g u l a r  NASTRAN ca ld s .  A simple case  con t ro l  deck i s  shown i n  Appendix B. 
Buik d a t a  must i nc lude  GRID c a r d s ,  -.le~nent connect ion ca rds  t o  d e f i n e  two dimen- 
s i o n a l  s u r f s c e s  and dummy proper ty  and m a t e r i a l  ca rds .  I n  a d d i t i o n  t he  SPC c a r d s  
con t a in  t he  information r equ i r ed  t o  gexera te  t he  contour  p l o t s .  A p p e ~ d i x  C shows a  
sample Bulk Data deck. 
EXAMPLES 
The f i r s t  r.red a t  B e l l  Aerospace Textron f o r  t h i s  uncommon a p p l i c a t i c n  a rose  
dur ing  thermal  s t r e s s  a n a l y s i s  of cooled l a s e r  m i r r r c s .  The tomperatlire d i s t r i b u t i o n  
on t he  mi r ro r  su r f ace  and t he  i n t e r i o r  was used a s  one of L e  load ing  cond i t i ons  f o r  
t he  s t r e s s  ana ly s i s .  The temperature had Deen computed u s i  ., a  f i n i t e  d i f f e r e n c e  
hea t  t r a n s f e r  program. An intermedicit _ FORTRAN prog-am genera ted  LASTRAN i n p u t  d a t a  
cards.  A s  a  v e r i f i c a t i o n  of i n p u t  cilta i t  wan decided t o  ob t a in  contour  p l o t s  of 
the i n p u t  t enpe ra tu r e  d i s t r i b u t i o n .  Typica l  temperature contour  p l o t  obtained is  
shown i n  F jzure  1. This  -2presen ts  t he  temperature d i s t r i b i r i o n  on t he  mi r ro r  f ace .  
This  p roces s  helped d e t e c t  -I$ c o r r e c t  e r r o r s  i n  t he  i n p u t  a ~ . r , l  For subsequent s t r u c -  
t u r a l  ana ly s i s .  
A second example of t he  succes s fu l  a 7 p l i c s t i o n  of t h i s  tect.nique r e i a t e s  t o  t h e  
angle of i r x idence  p l a t s  f o r  a i rbo rne  r ada r  a p p l i c a t i o n s .  S t r u c t u r a l  a n a l y s i s  of a 
t y p i c a l  radome housing was r equ i r ed  and a NASTRAN f i n i t e  element model was a l r eady  
ava i l ab l e .  The c u r r e n t  technique helped o b t a i n  contour  p l o t s  o t  the  angle of i n c i -  
dence on the  radome sur f  ace.  Th i s  provided user 'ul i n f o m :  on a t  r e l a t i v e l y  l i t t l e  
cos t .  A. s h o r t  FORTRAN program was w r i t t e n  t o  compute ang: s of inc idence  a t  a  given 
po in t  ny veading t he  coo rd ina t e s  of g r i d  p o i n t s  and computing normals t o  t he  neigh- 
boring e l e~uen t s .  Typica l  contour  p l o t  i s  shown i n  F igure  2. 
CONCLUDING REMARKS 
1. A s imple and inexpensive method of ob t a in ing  contour  p l o t s  of any nons t ruc t l l r a l  
q u a n t i t y  has been presen ted .  
2. This  method i s  most e f f i c i e n t  when a s t r u c t u r a l  f i n i t e  element model of t he  
su r f  ace on which coratour p l o t s  a r e  d e s i r e d ,  i s  a l r eady  a v a i l a b l e .  
3.  The phys i ca l  q u a n t i t y  i s  def ined  on SPC cards .  Usua l ly ,  an  i n t e rmed ia t e  com- 
pu t e r  program i s  h e l p f u l  i n  genera t ing  i npu t  d a t a  f o r  l a r g e  problems. 
h .  D M  ALTERS t o  be used i n  HEAT approach, Rigic' "ormat 1 a r e  provided. 
5. A9pl icat ions  a t  B e l l  Aer~aspace Tevtron have been varied and have pro-ridcd use-  
f u1 quick-look information. 
REFERENCE 
1. --- The NASTRAN User ' s  Manual, NASA SP-221(C6), Sectior.  1.4.5, September 1933. 
APPZWIX A 
SAMPLE EXECUTIVF CONTROL DECK 
NASTRAN BANDIT=-1 
I U SECL!IG-' EXAiWLE 
APF HEAT 
SJL 1 
T IHE  3 
ALTER 3 3 ~ 8 0  
PAF:AM / , / t N O F f  / ? I = - 1  $ 
ERUIU YSvHUGViPl $ 
SDR2 C A S E C C ~ C S T M ~ ~ P T ~ D I T ~ H E ~ E X I N ~ H S I L ~ G F ' T T ~ F I I T ~ B G P ~ ~ ~ T ~ ~ H U G U ~ ~ E ~ T ~ ~ /  
rrHOUGVJ9vvHPUEVl/SSTATICS* 3 
OFP HOUGUl r , r r , I S 9  N Y CARnNO $ 
ENDALTER 
CENa 
APPENDIX B 
SAMPLE CASE CONTROI DECK 
'T ITLE = NASTKAN USEK'S COLLORUIH # 13 
SUBTITLE = CONTOUR PLOTS O F  I N C I I i E N T  ANGLES 
LABEL = RADOHE SURFACE 
!$PC = 1 
THERMAL i F'PINT i = AL.L 
OUl PUT (PLO T i 
PL.OTTER NAEiTf L TI  HOI!EL D, 0 
F'APEK S I Z E  10.5 BY 3.0 
VIEW 0 + 0 . 3 t O 1 0 + 0  
AXES ZpX9Y 
S T  1 = R I J A D ~ I T R I A ~  
F I N D  SCALE-SET I Y O R I G I N  1 
13TITL..E = FRONT V I t W  
CUNTOUF tiAGNZTUD*LIST 0 + 0 9 1 0 ~ 0 1 2 0 ~ 0 9 3 ~ ~ 0 ~ 4 0 + 0 9 S 0 ~ 0 : 5 2 ~ 5 ~ 5 5 ~ @ 1  
57.51i0.0~62~5~65.0~~7.5~70~0~72.5~75.0~7~+5~~~.@~?0+0 
PLOT CONTOURI SET 1 9  O R I G I N  l r  OUTLINE 
BEGIN BULK 
APPENDIX C 
SAXPI-E BU1.K DATA DECK 
G R I D  420 9,816 8 , 6 3 3  2,439 
CRUAD2 420 101 420 520 C? .-s .l 1 421 
CTfi ' IA2 217 201 215 317 313 
IZ'QUAD2 10 I 1001 .001 
IZ 'TRlA? 201 1001 ,001 
HAT4 1001 1 ,O  
SPC 1 420 1 
ENDPATA 
OFUGW
AL PAGE fS 
OF POCR QUALITY. 
M
U
W
A
L PAGE rS 
OF W
O
R
 QUALIP( 


An Unusual Application of NASTRAN Contour Plotting Capability

Abstract

Similar works

Full text

Available Versions

NASA Technical Reports Server