13.

Post

proc

essi

ng

Post

proc

essi

ngO

verv

iew

�Th

ere

are

man

y w

ays

to re

view

resu

lts in

the

gene

ral

post

proc

esso

r (PO

ST1)

, som

e of

whi

ch h

ave

alre

ady

been

co

vere

d.

�In

this

cha

pter

, we

will

exp

lore

two

addi

tiona

l met

hods

�qu

ery

pick

ing

and

path

ope

ratio

ns �

and

also

intr

oduc

e yo

u to

the

conc

epts

of r

esul

ts tr

ansf

orm

atio

n, e

rror

est

imat

ion,

an

d lo

ad c

ase

com

bina

tion.

�To

pics

cov

ered

:A

. Q

uery

Pic

king

D.

Erro

r Est

imat

ion

B.

Res

ults

Coo

rdin

ate

Syst

emE.

Loa

d C

ase

Com

bina

tions

C.

Path

Ope

ratio

nsF.

Wor

ksho

p

Post

proc

essi

ngA

. Q

uery

Pic

king

�Q

uery

pic

king

allo

ws

you

to �

prob

e� th

e m

odel

for s

tres

ses,

di

spla

cem

ents

, or o

ther

resu

lts q

uant

ities

at a

ny p

icke

d lo

catio

n.

�Yo

u ca

n al

so q

uick

ly lo

cate

the

max

imum

and

min

imum

va

lues

of t

he it

em b

eing

que

ried.

�A

vaila

ble

only

thro

ugh

the

GU

I (no

com

man

ds):

�G

ener

alPo

stpr

oc>

Que

ry R

esul

ts >

Nod

al o

rEle

men

t orS

ubgr

id

Solu

...�

Cho

ose

a re

sults

qua

ntity

and

pre

ss O

K

Pow

erG

raph

ics

OFF

Pow

erG

raph

ics

ON

Post

proc

essi

ng...

Que

ry P

icki

ng

�Th

en p

ick

any

poin

t in

the

mod

el to

see

the

resu

lts v

alue

at t

hat

poin

t.�

Min

and

Max

will

sho

w th

e va

lue

at th

e m

inim

um a

nd

max

imum

poi

nts.

�U

se R

eset

to c

lear

all

valu

es a

nd s

tart

ove

r.�

Not

ice

that

the

entit

y nu

mbe

r, its

loca

tion,

and

the

resu

lts

valu

e ar

e al

so s

how

n in

the

Pick

er.

Post

proc

essi

ng...

Que

ry P

icki

ng

�D

emo:

�C

ontin

ue fr

om th

e la

st m

ulti-

load

-ste

p so

lutio

n of

rib.

db�

Plot

SEQ

V fo

r loa

d st

ep 1

�Q

uery

�N

odal

Solu

� SE

QV

at s

ever

al lo

catio

ns, i

nclu

ding

MIN

& M

AX.

(S

witc

h to

full

grap

hics

if n

eede

d.)

�Sw

itch

toPo

wer

Gra

phic

san

d qu

ery

�Sub

grid

Sol

u.�

Post

proc

essi

ngB

. R

esul

ts C

oord

inat

e Sy

stem

�A

ll di

rect

ion-

depe

nden

t qua

ntiti

es th

at y

ou v

iew

in P

OST

1,

such

as

com

pone

nt s

tres

ses,

dis

plac

emen

ts, a

nd re

actio

n fo

rces

, ar

e re

port

ed in

the

resu

lts c

oord

inat

e sy

stem

(RSY

S).

�R

SYS

defa

ults

to 0

(glo

bal C

arte

sian

). T

hat i

s, P

OST

1 tr

ansf

orm

s al

l res

ults

to g

loba

l Car

tesi

an b

y de

faul

t, in

clud

ing

resu

lts a

t �ro

tate

d� n

odes

.

�B

ut th

ere

are

man

y si

tuat

ions

�su

ch a

s pr

essu

re v

esse

ls

and

sphe

rical

str

uctu

res

�w

here

you

nee

d to

che

ck th

e re

sults

in a

cyl

indr

ical

, sph

eric

al, o

r oth

er lo

cal c

oord

inat

e sy

stem

.

Post

proc

essi

ng...

Res

ults

Coo

rdin

ate

Syst

em

�To

cha

nge

the

resu

lts C

S to

a

diffe

rent

sys

tem

, use

:�

Gen

eral

Post

proc

> O

ptio

ns fo

rOut

p��

or th

e R

SYS

com

man

d

All

subs

eque

nt c

onto

ur p

lots

, lis

tings

, que

ry p

icks

, etc

. will

re

port

the

valu

es in

that

sys

tem

.

Def

ault

orie

ntat

ion

RSY

S,0

Loca

l cyl

indr

ical

sy

stem

RSY

S,11

Glo

bal c

ylin

dric

al

syst

em R

SYS,

1

Post

proc

essi

ng...

Res

ults

Coo

rdin

ate

Syst

em

�R

SYS,

SOLU

�Se

ts th

e re

sults

CS

to �

as-c

alcu

late

d.�

�A

ll su

bseq

uent

con

tour

plo

ts, l

istin

gs, q

uery

pic

ks, e

tc. w

ill

repo

rt th

e va

lues

in th

e no

dal a

nd e

lem

ent c

oord

inat

e sy

stem

s.�

DO

F re

sults

and

reac

tion

forc

es w

ill b

e in

the

noda

l CS.

�St

ress

es, s

trai

ns, e

tc. w

ill b

e in

the

elem

ent C

S. (

The

orie

ntat

ion

of th

e el

emen

t CS

depe

nds

on th

e el

emen

t typ

e an

d th

e ES

YS a

ttrib

ute

of th

e el

emen

t. M

ost s

olid

ele

men

ts,

for e

xam

ple,

def

ault

to g

loba

l Car

tesi

an.)

�N

ot s

uppo

rted

by

Pow

erG

raph

ics.

Post

proc

essi

ngC

. Pa

th O

pera

tions

�A

noth

er w

ay to

revi

ew re

sults

is v

ia p

ath

oper

atio

ns, w

hich

al

low

you

to:

�m

ap re

sults

dat

a on

to a

n ar

bitr

ary

�pat

h� th

roug

h th

e m

odel

�pe

rfor

m m

athe

mat

ical

ope

ratio

ns a

long

the

path

, inc

ludi

ng

inte

grat

ion

and

diffe

rent

iatio

n�

disp

lay

a �p

ath

plot

� �

see

how

a re

sult

item

var

ies

alon

g th

e pa

th

�A

vaila

ble

only

for m

odel

s co

ntai

ning

2-D

or 3

-D s

olid

el

emen

ts o

r she

ll el

emen

ts.

Post

proc

essi

ng...

Path

Ope

ratio

ns

�Th

ree

step

s to

pro

duce

a p

ath

plot

:�

Def

ine

a pa

th�

Map

dat

a on

to th

e pa

th�

Plot

the

data

1. D

efin

e a

Path

�R

equi

res

the

follo

win

g in

form

atio

n:�

Poin

ts d

efin

ing

the

path

(2 to

100

0).

You

can

use

exis

ting

node

s or

loca

tions

on

the

wor

king

pla

ne.

�Pa

th c

urva

ture

, det

erm

ined

by

the

activ

e co

ordi

nate

sys

tem

(C

SYS)

.�

A n

ame

for t

he p

ath.

Post

proc

essi

ng...

Path

Ope

ratio

ns

1. D

efin

e a

Path

(con

t�d)

�Fi

rst a

ctiv

ate

the

desi

red

coor

dina

te s

yste

m (C

SYS)

.�

Gen

eral

Post

proc

> Pa

th O

pera

tions

> D

efin

e Pa

th >

By

Nod

esor

On

Wor

king

Pla

ne�

Pick

the

node

s or

WP

loca

tions

that

form

the

desi

red

path

, an

d pr

ess

OK

�C

hoos

e a

path

nam

e. T

henS

ets

and

nDiv

field

s ar

e be

st le

ft to

def

ault

in m

ost c

ases

.

Post

proc

essi

ng...

Path

Ope

ratio

ns

2. M

ap D

ata

onto

Pat

h�

Gen

eral

Post

proc

> Pa

th O

pera

tions

> M

ap o

nto

Path

� (

or P

DEF

com

man

d)�

Cho

ose

desi

red

quan

tity,

suc

h as

SX.

�En

ter a

labe

l for

the

quan

tity,

to b

e us

ed o

n pl

ots

and

listin

gs.

�Yo

u ca

n no

w d

ispl

ay th

e pa

th if

nee

ded.

�G

ener

alPo

stpr

oc>

Path

Ope

ratio

ns >

Plo

t Pat

hs�

(or i

ssue

/PBC

,PAT

H,1

follo

wed

by

NPL

OT

or E

PLO

T)

Post

proc

essi

ng...

Path

Ope

ratio

ns

3. P

lot t

he D

ata

�Yo

u ca

n pl

ot p

ath

item

s ei

ther

on

a gr

aph:

�PL

PATH

or G

ener

alPo

stpr

oc>

Path

Ope

ratio

ns >

On

Gra

ph...

�or

alo

ng p

ath

geom

etry

:�

PLPA

GM

or G

ener

alPo

stpr

oc>

Path

Ope

ratio

ns >

On

Geo

met

ry...

Post

proc

essi

ng...

Path

Ope

ratio

ns

�A

NSY

S al

low

s yo

u to

def

ine

mul

tiple

pat

hs, e

ach

with

a

uniq

ue n

ame

that

you

ass

ign.

O

nly

one

path

can

be

activ

e at

a ti

me.

�B

esid

es p

lots

and

list

ings

, the

re a

re m

any

othe

r pat

h ca

pabi

litie

s, in

clud

ing:

�St

ress

linea

rizat

ion

�us

ed in

the

pres

sure

ves

sel

indu

stry

to d

ecom

pose

str

ess

alon

g a

path

into

its

mem

bran

e an

d be

ndin

g co

mpo

nent

s.�

Cal

culu

s fu

nctio

ns �

used

in fr

actu

re m

echa

nics

to

calc

ulat

e J-

inte

gral

s an

d st

ress

con

cent

ratio

n fa

ctor

s.

Als

o us

eful

in th

erm

al a

naly

ses

to c

alcu

late

the

heat

lost

or

gai

ned

acro

ss a

pat

h.�

Dot

pro

duct

s an

d cr

oss

prod

ucts

�us

ed w

idel

y in

el

ectr

omag

netic

s an

alys

es to

ope

rate

on

vect

or

quan

titie

s.

Post

proc

essi

ng...

Path

Ope

ratio

ns

�D

emo:

�C

ontin

ue w

ith ri

b po

stpr

oces

sing

��

Plot

nod

es, t

hen

switc

h to

CSY

S,1

if de

sire

d�

Def

ine

a pa

th u

sing

nod

es�

Map

SX

or S

EQV

or o

ther

dat

a on

to p

ath

�Pl

ot th

e pa

th it

self

�Pl

ot th

e pa

th it

em o

n gr

aph

and

on g

eom

etry

�D

efin

e a

seco

nd p

ath

else

whe

re in

the

mod

el a

nd s

how

how

to to

ggle

be

twee

n th

e tw

o.

Post

proc

essi

ngD

. Er

ror E

stim

atio

n

�Th

e fin

ite e

lem

ent s

olut

ion

calc

ulat

es s

tres

ses

on a

per

-el

emen

tbas

is, i

.e, s

tres

ses

are

indi

vidu

ally

cal

cula

ted

in e

ach

elem

ent.

�W

hen

you

plot

nod

alst

ress

con

tour

s in

PO

ST1,

how

ever

, you

w

ill s

ee s

moo

th c

onto

urs

beca

use

the

stre

sses

are

ave

rage

dat

the

node

s.

If yo

u pl

ot th

e el

emen

t sol

utio

n, y

ou w

ill s

eeun

aver

aged

data

, w

hich

sho

ws

the

disc

ontin

uity

bet

wee

n el

emen

ts.

Elem

1El

em 2

σ avg

= 11

00

σ=

1200

σ=

1000 σ a

vg=

1200

σ=

1300

σ=

1100

�Th

e di

ffere

nce

betw

een

aver

aged

and

unav

erag

edst

ress

es g

ives

an

indi

catio

n of

how

�go

od�

or h

ow �

bad�

th

e m

esh

is.

This

is th

e ba

sis

for e

rror

es

timat

ion.

Post

proc

essi

ng...

Erro

r Est

imat

ion

�Er

ror e

stim

atio

n is

ava

ilabl

e on

ly in

PO

ST1

and

is v

alid

onl

y fo

r: �lin

ear s

tatic

str

uctu

ral a

nd li

near

ste

ady-

stat

e th

erm

al a

naly

ses

�so

lid e

lem

ents

(2-D

and

3-D

) and

she

ll el

emen

ts�

full

grap

hics

(not

Pow

erG

raph

ics)

If th

ese

cond

ition

s ar

e no

t met

, AN

SYS

auto

mat

ical

ly tu

rns

off e

rror

est

imat

ion

calc

ulat

ions

.

�To

man

ually

act

ivat

e or

dea

ctiv

ate

erro

r est

imat

ion,

use

�ER

NO

RM

,ON

/OFF

�or

Gen

eral

Post

proc

> O

ptio

ns fo

rOut

p...

Post

proc

essi

ng...

Erro

r Est

imat

ion

�PO

ST1

calc

ulat

es th

e fo

llow

ing

erro

r mea

sure

s.�

Stre

ss a

naly

sis:

�pe

rcen

tage

err

or in

ene

rgy

norm

(SEP

C)

�el

emen

t str

ess

devi

atio

ns (S

DSG

)�

elem

ent e

nerg

y er

ror (

SER

R)

�m

axim

um a

nd m

inim

um s

tres

s bo

unds

(SM

XB, S

MN

B)

�Th

erm

al a

naly

sis:

�pe

rcen

tage

err

or in

ene

rgy

norm

(TEP

C)

�el

emen

t the

rmal

gra

dien

t dev

iatio

ns (T

DSG

)�

elem

ent e

nerg

y er

ror (

TER

R)

Post

proc

essi

ng...

Erro

r Est

imat

ion

Perc

enta

ge e

rror

in e

nerg

y no

rm (S

EPC

)

�SE

PC is

a ro

ugh

estim

ate

of th

e st

ress

err

or (o

r di

spla

cem

ent,

tem

pera

ture

, or t

herm

al fl

ux) o

ver t

he e

ntire

set

of

sel

ecte

d el

emen

ts.

�C

an b

e us

ed to

com

pare

sim

ilar m

odel

s of

sim

ilar s

truc

ture

s su

bjec

ted

to s

imila

r loa

ding

s.

�SE

PC is

sho

wn

in th

e le

gend

col

umn

of d

efor

med

sha

pe

disp

lays

. Yo

u ca

n lis

t it m

anua

lly u

sing

PR

ERR

or G

ener

alPo

stpr

oc>

List

Res

ults

> P

erce

nt E

rror.

Post

proc

essi

ng...

Erro

r Est

imat

ion

�A

s a

gene

ral r

ule

of th

umb,

lo

ok fo

r SEP

C to

be

10%

or

less

. If

it is

hig

her,

then

:�

Che

ck fo

r poi

nt lo

ads

or

othe

r str

ess

sing

ular

ities

an

d un

sele

ct e

lem

ents

in

the

vici

nity

.�

If it

is s

till h

ighe

r, pl

ot th

e el

emen

t ene

rgy

erro

r. T

he

elem

ents

with

hig

h va

lues

of

ene

rgy

erro

r are

ca

ndid

ates

for m

esh

refin

emen

t.

Post

proc

essi

ng...

Erro

r Est

imat

ion

Elem

ent s

tres

s de

viat

ions

(SD

SG)

�SD

SG is

a m

easu

re o

f the

am

ount

by

whi

ch a

n el

emen

t�s s

tres

s di

sagr

ees

with

the

stre

ss a

vera

ges

at it

s no

des.

�Yo

u ca

n pl

ot S

DSG

con

tour

s us

ing

PLES

OL,

SDSG

or G

ener

alPo

stpr

oc>

Plot

Res

ults

> E

lem

entS

olu.

..

�A

hig

h va

lue

of S

DSG

is n

ot

nece

ssar

ily b

ad, e

spec

ially

if it

is a

sm

all p

erce

ntag

e of

the

nom

inal

st

ress

es in

the

stru

ctur

e.

For e

xam

ple,

this

pla

te-w

ith-a

-hol

e m

odel

sho

ws

only

a 1

.5%

str

ess

devi

atio

n in

the

regi

on o

f int

eres

t.

SDSG

at l

ocat

ion

of in

tere

st

= ~4

50 p

si, w

hich

is ~

1.5%

of

~30,

000

psi n

omin

al s

tres

s

Post

proc

essi

ng...

Erro

r Est

imat

ion

Elem

ent e

nerg

y er

ror (

SER

R)

�SE

RR

is th

e en

ergy

ass

ocia

ted

with

the

stre

ss m

ism

atch

es a

t th

e no

des

of th

e el

emen

t. T

his

is th

e ba

sic

erro

r mea

sure

fr

om w

hich

the

othe

r err

or q

uant

ities

are

der

ived

. SE

RR

has

un

its o

f ene

rgy.

�To

plo

t SER

R c

onto

urs,

issu

e PL

ESO

L,SE

RR

or G

ener

alPo

stpr

oc>

Plot

Res

ults

> E

lem

entS

olu.

..

�G

ener

ally

, the

ele

men

ts w

ith th

e hi

ghes

t SER

R a

re

cand

idat

es fo

r mes

h re

finem

ent.

How

ever

, sin

ce S

ERR

will

al

way

s be

hig

hest

at s

tres

s si

ngul

ariti

es, b

e su

re to

uns

elec

t th

ose

elem

ents

firs

t.

Post

proc

essi

ng...

Erro

r Est

imat

ion

Stre

ss b

ound

s (S

MXB

and

SM

NB

)

�Th

e st

ress

bou

nds

can

help

you

det

erm

ine

the

pote

ntia

l ef

fect

of m

esh

disc

retiz

atio

ner

ror o

n th

e m

axim

um s

tres

s.

�Th

ey a

re d

ispl

ayed

on

stre

ss c

onto

ur p

lots

in th

e le

gend

co

lum

n as

SM

XB (u

pper

bou

nd) a

nd S

MN

B (l

ower

bou

nd).

�Th

e bo

unds

are

not

estim

ates

of t

he a

ctua

l max

imum

and

m

inim

um, b

ut th

ey d

o de

fine

a �c

onfid

ence

ban

d.�

With

out

othe

r sup

port

ing

verif

icat

ion,

you

hav

e no

bas

is fo

r bel

ievi

ng

that

the

true

max

imum

str

ess

is b

elow

SM

XB.

�C

autio

n:If

you

don�

t uns

elec

t ele

men

ts n

ear s

tres

s si

ngul

ariti

es, t

he s

tres

s bo

unds

are

mea

ning

less

, as

show

n be

low

.

Post

proc

essi

ng...

Erro

r Est

imat

ion

Post

proc

essi

ngE.

Loa

d C

ase

Com

bina

tions

�W

hene

ver y

ou s

olve

mul

tiple

load

ste

ps, t

he re

sults

of e

ach

load

ste

p ar

e st

ored

as

sepa

rate

set

s on

the

resu

lts fi

le

(iden

tifie

d by

load

ste

p nu

mbe

r).

�A

load

cas

e co

mbi

natio

nis

an

oper

atio

n be

twee

n tw

o se

ts o

f re

sults

, whi

ch a

re c

alle

d lo

ad c

ases

.�

The

oper

atio

n oc

curs

bet

wee

n on

e lo

ad c

ase

in th

e da

taba

se

and

the

seco

nd lo

ad c

ase

on th

e re

sults

file

.�

The

resu

lt of

the

oper

atio

n �

the

com

bine

d lo

ad c

ase

�is

st

ored

bac

k in

the

data

base

.

Load

cas

e in

dat

abas

e(c

ompu

ter m

emor

y)Lo

ad c

ase

on re

sults

file

Com

bine

d lo

ad c

ase

in d

atab

ase

over

writ

es p

revi

ous

cont

ents

Post

proc

essi

ng...

Load

Cas

e C

ombi

natio

ns

Typi

cal p

roce

dure

:

1.C

reat

e th

e lo

ad c

ases

2.R

ead

one

load

cas

e in

to th

e da

taba

se

3.Pe

rfor

m th

e de

sire

d op

erat

ion

Post

proc

essi

ng...

Load

Cas

e C

ombi

natio

ns

Cre

ate

Load

Cas

es

�A

load

cas

e si

mpl

y ac

ts a

s a

poin

ter t

o a

set o

f re

sults

. It

requ

ires

two

piec

es o

f inf

orm

atio

n:�

a un

ique

ID n

umbe

r�

the

resu

lts s

et it

repr

esen

ts (l

oad

step

and

subs

tep

num

ber)

�U

se th

e LC

DEF

com

man

d or

Gen

eral

Post

proc

> Lo

ad C

ase

> C

reat

e Lo

ad C

ase

Post

proc

essi

ng...

Load

Cas

e C

ombi

natio

ns

Rea

d O

ne L

oad

Cas

e in

to th

e D

atab

ase

�Si

mpl

y id

entif

y th

e re

sults

set

by

its lo

ad c

ase

num

ber u

sing

LC

ASE

or G

ener

alPo

stpr

oc>

Load

C

ase

> R

ead

Load

Cas

e.

�O

r use

one

of t

he s

tand

ard

�Rea

d R

esul

ts�

choi

ces

in th

e po

stpr

oces

sor (

SET

com

man

d).

Post

proc

essi

ng...

Load

Cas

e C

ombi

natio

ns

Perf

orm

the

Des

ired

Ope

ratio

n

�M

any

oper

atio

ns a

re a

vaila

ble

as s

how

n in

the

men

u he

re.

�U

se th

e LC

OPE

Rco

mm

and

or G

ener

alPo

stpr

oc>

Load

Cas

e >

Add,

Sub

tract

, etc

.

�R

emem

ber t

hat t

he re

sults

of t

he o

pera

tion

are

stor

ed in

the

data

base

. Th

e co

mbi

ned

load

cas

e is

id

entif

ied

on p

lots

and

list

ings

as

num

ber 9

999.

Post

proc

essi

ng...

Load

Cas

e C

ombi

natio

ns�

Ther

e ar

e tw

o us

eful

opt

ions

to s

ave

the

com

bine

d lo

ad c

ase:

�W

rite

a lo

ad c

ase

file

�A

ppen

d th

e lo

ad c

ase

to th

e re

sults

file

�W

ritin

g a

load

cas

e fil

e(L

CW

RIT

Eor

Gen

eral

Post

proc

Writ

e R

esul

ts) c

reat

es a

fil

e th

at is

sim

ilar t

o, b

ut m

uch

smal

ler t

han

the

resu

lts fi

le.

�Th

e A

ppen

dop

tion

(RAP

PND

or G

ener

alPo

stpr

oc>

Load

Cas

e >

Writ

e Lo

ad

Cas

e) a

llow

s yo

u to

add

the

com

bine

d lo

ad c

ase

to th

e re

sults

file

and

id

entif

y it

with

a g

iven

load

ste

p nu

mbe

r and

tim

e va

lue.

Post

proc

essi

ngF.

Wor

ksho

p

�Th

is w

orks

hop

cons

ists

of t

hree

exe

rcis

es:

W12

A.

Con

nect

ing

Rod

W12

B.

Sphe

rical

She

llW

12C

.A

xisy

mm

etric

Fin

with

Mul

tiple

Loa

d St

eps

Ref

er to

you

r Wor

ksho

p Su

pple

men

tfor

inst

ruct

ions

.