MECH 387 - Lab Exercise 9 - Fatigue Analysis

8/18/2019 MECH 387 - Lab Exercise 9 - Fatigue Analysis

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Exe r cise 9

Introduction to ANSYS WorkbenchANSYS Mechanical V - Fatigue Analysis

Indi idual Exercise

ME!" #$% & S'ring ()*+

,ab Instructors Syed Murtaza Jaffar (syed.jaffar @ kustar.ac.ae ) Shaohong Lou ( 10004225 @kustar.ac.ae) !"dur #osy$d %atru& ( [email protected]) 'he$kh '$sse ( 1000 0 @kustar.ac.ae)

,ab "ours- * ng$nee r $ng +u$,d$ng- #oo& 122- Sunday 2/(0 5/00 &- Sunday 5/10 /40 & 3 uesday 2/(0 5/00 1&

Startu' Ste's,og into the student account us$ng the fo,,o $ng $nfor&at$on/

,ogin student.ass/ord student12(4

MECH 387 Spring 2016 Prepared by Syed M. Jaffar ANSYS Mec anica! "#r$benc %&'#ria!(

mailto:([email protected]:([email protected]:([email protected]:([email protected]


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Start ANSYS "y ,ocat$ng the Workbench $con. h$s startu $con can "e res$d$ng onthe deskto' or $th$n the Start &enu..roble0 1esc r i' t ion6n th$s e7erc$se- e $,, use the Fatigue 2ool $n !8S9S Mechan$ca, to erfor& the

fo,,o $ng/

:at$gue Stress !na,ys$s Setu:at$gue ,oad$ng of duct$,e &ater$a,s:at$gue ,$fe and Safety factor co& utat$ons:$,,et *ffect on :at$gue L$fe

Su00ary o3 S t e ' s

6n genera,- fo,,o $ng ste s are carr$ed out hen so,;$ng for the res onse to astructure under a ,$ed ,oads/

*4


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Fatigue ,oading o3 a 2hin 7ectangular .late /ith a !ircular "ole

6n th$s e7erc$se- e $,, atte& t to use the Wi8ard in ANSYS to so,;e for thefat$gue ,$fe of a th$n rectangu,ar ,ate $th a c$rcu,ar ho,e.

he d$&ens$ons of the ,ate are as fo,,o s/

Length = 1? 00 &&e$ght =A2? 2B0 &&

C$dth =*7trus$on? 5 &&o,e D$a&eter =D ? 100 &&

Figure * 2hin 7ectangular .late /ith a !ircular "ole

Launch !8S9S

'reate the geo&etry us$ng the 1esignModeler and after the geo&etry creat$on-c,ose the Des$gnMode,er.



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Start Static Structural Modu,e "y dou",e c,$ck$ng on $t.

L$nk the


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:$gure 1/ Mechan$ca, ! ,$cat$on C$zard

',$ck on !hoose Wi8ard and fro& the ,$st that a ears- c,$ck on the Fatigueanalysis .



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:$gure 2/ 'hoose C$zard Menu

he 7e:uired Ste's &enu to so,;e a fat$gue ro",e& o s u /



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:$gure (/ #e>u$red Ste s

Start c,$ck$ng on the ste s start$ng fro& Insert Fatigue Analysis

:ro& the 2ools co&&and fro& the So,ut$on Menu- choose Fatigue 2ool heCorksheet $ndo a ears as fo,,o s/



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:$gure 4/ :at$gue Corksheet

he :at$gue Corksheet a"o;e sho s the defau,t setu for so,;$ng the fat$guero",e& at hand.

he $ndo sho s that a 3ully re ersed and constant a0'litude ,oad$ng $s to"e a ,$ed to the &ode, under $n;est$gat$on. Fur &ode, $s a th$n f,at ,atecarry$ng a c$rcu,ar ho,e def$ned $n the Des$gnMode,er re;$ous,y.

he roject out,$ne "e,o sho s a Fatigue 2ool a ear$ng under the So,ut$on&enu/

:$gure 5/ %roject Fut,$nehe 1etails o3 ;Fatigue 2ool< $,, ,et the user chose $& ortant des$gn



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:$gure / *ng$neer$ng Data



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:$gure B/ SE8 Data for Structura, Stee,

! log-log gra'h of the Stee, !,ternat$ng Stress ;ersus 'yc,es $,, a ear onthe ,o er ,eft s$de as sho n a"o;e.

Just a"o;e the ,ogE,og ,ot- you $,, see the SE8 data rang$ng fro& 10 cyc,es toa &$,,$on cyc,es. 6n th$s SE8 data- note that the ,ast entry $s $+ ( M.a at *) + cycles .

*7$t the *ng$neer$ng Data after ;er$fy$ng that the SE8 data for Structura,Stee, e7$sts and return to !8S9S Mechan$ca,.



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Insert Structural ,oads ! ,y a tens$,e ,oad of 6) kN to the r$ght face ofthe ,ate.

Insert Su''orts he ,eft face of the ,ate $s the f$7ed su ort.

Insert Fatigue 7esults / 6nsert ,i3e - Sa3ety Factor and E:ui alent AlternatingStress $n the :at$gue oo,.

>e3ore sol ing for the resu,ts- &ake sure that the Mesh conf$gurat$on $s asfo,,o s/

Si8ing

!d;anced S$ze :unct$on Fn/ 'ur;ature #e,e;ance 'enter :$ne S&ooth$ng Med$u& 'ur;ature 8or&a, !ng,e 5 degrees

Sol e

',$ck on ,i3e and note the 0ini0u0 alue h$s g$;es the &$n$&u& cyc,es tofat$gue. 2his is the 3atigue li3e o3 the s'eci0en under 3ully re ersed loading

o3 6) kN

',$ck on *>u$;a,ent !,ternat$ng Stress. 8ote that th$s ;a,ue $s 0ore than the,o est o$nt $n the SE8 data cur;e of B .2 M%a . It sho/s that this 'art underthe s'eci3ied loading and geo0etry /on?t ha e in3inite li3e

Fill out 2able * "e,o "y not$ng do n the alues for the ;ar$a",es sho n "e,o .Make sure that you carry out the ref$ne&ent. Hse the fo,,o $ng sett$ngs for

the &esh/



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Mean Stress2heory

,oadingMagnitudekN

Max E:uiAlternating

Stress -M.a

Fatigue,i3e -!ycles

Sa3etyFactor

Max Von-Mises

Stress -M.a

:u,,y #e;ersed 50 k8

8one 50

Soder"erg 50


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@uestions

.art A

Flat .late /ith a S:uare "ole

#e eat the a"o;e rocedure for the 3lat 'late /ith a s:uare hole . Hse thesa&e d$&ens$ons as g$;en $n the ro",e&. 6n art$cu,ar- take the s>uare ho,ed$&ens$on to "e 100 && and ,ace $t $n the &$dd,e of the ,ate. Introduce3illets o3 radius *) 00 3or all corners . Fill out 2able ( "e,o /

Mean Stress2heory

,oadingMagnitudekN

Max E:uiAlternating

Stress -M.a

Fatigue,i3e -!ycles

Sa3etyFactor

Max Von-Mises

Stress -M.a

:u,,y #e;ersed 50 k8

8one 50

Soder"erg 50

uare o,e

.lot all 3our out'ut :uantities =Ma7$&u& *>u$;a,ent !,ternat$ng Stress-:at$gue L$fe- Safety :actor and Ma7$&u& ;onEM$ses Stress? on se'arate barcharts .



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.art >

.late /ith a !ircular "ole & ,oad to 0atch 3atigue li3e o3 *e)+ !ycles

:or the ,ate $th a c$rcu,ar ho,e- e are seek$ng the a ,$ed ,oad h$ch $,,resu,t $n the fat$gue ,$fe of 1e0 . h$s a,so resu,ts $n the e>u$;a,ent a,ternat$ngstress of B .2 M%a as g$;en $n the ta",e.

! ,$ed ,oad$ng of :u,,y #e;ersed 6)kN resu,ted $n an *>u$;a,ent !,ternat$ngStress of a ro7$&ate,y *(+ 55 M.a . h$s ;a,ue $s h$gher than $+ ( M.a h$ch$s the fat$gue ,$&$t for th$s &ater$a, "ased on the des$gn cyc,es of 1e0 . 6t&eans that a ,oad$ng of 50 k8 $,, resu,t $n fa$,ure of the ,ate $f the cyc,es

ers$st for 1. 5e 05 count. +ut $f e decrease the ,oad$ng &agn$tude- there$,, "e a ,e;e, "e,o h$ch there onKt "e any fa$,ure- $n genera,. ence "e,o

that ,e;e, of a ,$ed force- th$s art $,, not fa$, no &atter ho &any cyc,es area ,$ed. hat e7act,y &eans In3inite ,i3e

Methodology

* 'hange the ,oad$ng fro& 50 k8 to 45 k8 and f$,, out the a ro r$ate ro $nthe ta",e "e,o . 'hange the a ,$ed ,oad to 40 k8 and note do n theresu,t$ng >uant$t$es. ee' re'eating the sa0e 'rocedure Blo/er the a''liedload4 till you obtain the resulting E:ui alent Alternating Stress to be'recisely e:ual to $+ ( M.a

2. 9ou &ay ha;e to a ,y the ,oad $n SM!LL*# $ncre&ents hen you get c,oseto the target ;a,ue of B .2 M%a for the *>u$;a,ent !,ternat$ng Stress Hse

your o n eng$neer$ng judg&ent.



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A''lied 2ensile,oad BkN4

E:ui alentAlternating

Stress - M.a

,i3e !ycles -!ycles

Sa3etyFactor

VonCMisesE:ui alent

Stress -M.a

50 12 .44 1.( (5e05 0. B1 12 .44

45

40

B .2 1e 0 1

a",e (/ %,ate $th #ound o,e E ! ,$ed ens$,e Load As :at$gue %ara&eters=:u,,y #e;ersed Load$ng 50 k8- Iero Mean Stress?

.lot the ! ,$ed ens$,e Load ;ersus *>u$;a,ent !,ternat$ng Stress- the L$fe'yc,es- the Safety :actors and the ;onEM$ses Stress. Gee the tens$,e ,oad onthe 7Ea7$s.

N=2E :or the ana,ys$s $n %art +- kee the loading to "e Fully 7e ersed @ 50k8 and do not use any Mean Stress 2heory .

.art ! - >onus MECH 387 Spring 2016 Prepared by Syed M. Jaffar ANSYS Mec anica! "#r$benc %&'#ria!(


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.late /ith a S:uare "ole & E33ect o3 Stress !oncentration on Fatigue ,i3e

9ou $,, study the e33ect o3 stress concentrations on 3atigue li3e for the

,ate $th a s:uare hole . ake the f$,,et rad$$ to "e 2- - 10- 14- 1B and 22 &&res ect$;e,y. 'arry out the ana,ys$s and co0'ute the load re>u$red $n each caseto roduce 1e 0 cyc,es to fa$,ure.

:$,, out the ta",e "e,o /

Fillet 7adius B004 A''lied 2ensile ,oad 3or In3inite,i3e BkN4 o3 *e)+ !ycles

24

B

10

12

14

1

1B

20

a",e 4/ %,ate $th S>uare o,e E ! ,$ed ens$,e Load for 6nf$n$te L$fe As :$,,et

#ad$us

.lot the a''lied tensile load 3or in3inite li3e against the 3illet radius

.ara0eters - .art !

,oading MECH 387 Spring 2016 Prepared by Syed M. Jaffar ANSYS Mec anica! "#r$benc %&'#ria!(


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y e IeroE+ased Sca,e :actor 1

='tions

!na,ys$s y e E Stress L$fe Mean Stress heory E


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Sub0issions

* .ractice Exercise 100 Marksa. !8S9S E 20

". a",e E 0c. 'hart E 10( .art A 100 Marks

a. !8S9S E 20". a",e E 0c. 'hart E 10

# .art > 200 Marksa. !8S9S E 40". a",e E 140

c. 'hart E 205 .art ! & >onus B#)) Marks Scaled to * .oint & Si0ilar to the 1M >onus4a. !8S9S E 40". a",e E 240c. 'hart E 20

MECH 387 Spring 2016 Prepared by Syed M. Jaffar $

MECH 387 - Lab Exercise 9 - Fatigue Analysis

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