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MET 425 - FEA Applications II

Prof. Dave Johnson, psuprof !"psu.e uPenn #tate - Er ie, The $ehren %olle&e

Final Pro!ect' A#ME %o e an FEA Anal(sis

%oncepts'

Transient T hermal AnalysisThermal-Stress AnalysisNonlinear material behavior Linearized Stress ResultsExposure to ASME Codechec s

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The !i"ures above !rom http#$$%%%&nrc&"ov$reactors$operatin"$ops-experience$vessel-head-de"radation$ima"es&html sho% a typical nuclear reactor& The control rods are raised and lo%ered throu"h a nozzle-shaped port on the reactor head& Althou"hthere are many o! these nozzles on the reactor head' it is common to analyze one o! them in a t%o-dimensional'axisymmetric analysis& Stresses need to be evaluated throu"h speci!ic locations in the nozzle %all usin" alinearized-stress method&

Background: Davis Besse is a reactor in northern Ohio on the southwest shore of Lake Erie. A corrosion problem wasdetected in 2 2 at the no!!le"reactor head fillet. #his fillet location is also a location of high stress and a weakening of the head in this location might have leaked$flooded the containment building with coolant from the reactor. %epairsre&uired two 'ears.

A typical nozzle-reactor head (oint is the !ocus o! this analysis pro(ect& )e can develop a *+ model o! the re"iono! interest& ,ou may clic here to access the araSolid .ile /0se a Ri"ht-clic on this lin ' then 1Save Tar"et

As&&&1' then 1Save as type# All .iles1' and use a !ile name li e# 1!ea*2p%r23eom*+&x2t1 4

+imensions# A5 6 5&7o

Nozzle 8utsideRadius'9: 6 * in&Nozzle )allThic ness'9; 6 nside Radius'R7 6 55&7? in&9ead 8utsideRadius'R= 6 ;?&7? in&Nozzle Len"th'@ < 6 * in&

)eld +imensions#

)idth o! )eld Notch'9 ? 6

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.or thermal-stress analysis' the Re!erence Temperature is *< .&

)oa Data' (Note: we are converting the blow-off force to a pressure input)

Time >nsideConvectionTEM

>nsideressure

lo%-o!! .orce

lo%-o!! ressure

secD .D psiD lb!D psiD

*< ?B *?** -?7

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.or 8T9 the thermal transient analysis and the static structural analysis' the >nitial Temperature is *< .&

Transient Ther*al )oa #TEP Data f or Ti*e Inte&ration an +utput %ontrols'

Since ANS,S 8NL, reads in temperature data !or each L8A+ STE it does N8T interpolate temperature data !romthe thermal analysis !or intermediate S0 STE SD' %e %ill set up ?* load steps to attempt to capture critical timepoints durin" the static structural analysis& Each load step %ill reFuire only one substep since %e are usin" linear material properties !or this simulation&

#tatic #tructural )oa #TEP Data an +utput %ontrols'

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+TE' e ti*es/loa s are inte rpola te fro* the &iven loa histor(0 This ata is provi e in a a ta1- eli*ite te t file' fea23p r-static3struct3loa 3s teps.t t

8nce the load steps have been set up' ma e sure the 1>mported ody Temperature1 table sho%s the correct 1SourceTime1 !or each static structural analysis load step& >t should loo li e this#

The ASME Code "ives desi"n stress intensity in!ormation !or the material used !or this analysis#

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The simulation speci!ication !or this analysis reFuires the boundary bet%een the nozzle and head be connected !or the transient thermal analysis' but !or the thermal stress model' this boundary condition is to be detached& >n ANS,SMechanical' %e are not permitted to chan"e contact behavior bet%een lin ed analyses& So' a command ob(ect canbe placed $EF+ E Solution to 1 ill1 a speci!ic pair o! bonded contacts& N8TE# this operation assumes thecontact$tar"et pairs bet%een the nozzle and head are identi!ied as element types : and 7& C8N.>RM that this %or s!or your model&

ESEL,S,TYPE,,4,5 ! Select the contact-target elem btw. nozzle a nd head EKILL,ALL ! K ll tho e element " tr#ct#ral anal$ , onl$%

ESEL,ALL ! Select all element

First un one in 6-70' Run a static structural analysis to validate the model& 0se 0ni!orm Temperatureo! *< .' Re!erence Temperature o! *

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en"ineerin" technolo"y solutions in a societal and "lobal context're!erence to appropriate technical literature o! our discipline

:>>' N ?*** $ N -?**? evaluate D total RAN3E O hi"hest total stresstimes& /Assume minimum S>NT 6 TSD'etc&