ML22271A650
| ML22271A650 | |
| Person / Time | |
|---|---|
| Site: | Orano USA |
| Issue date: | 05/13/2022 |
| From: | Framatome |
| To: | Division of Fuel Management |
| Garcia-Santos N | |
| Shared Package | |
| ML22271A128 | List:
|
| References | |
| A33010, L-2022-DOT-0007 | |
| Download: ML22271A650 (41) | |
Text
No of 41 Pages:
framatome Document Type:
AC- DESIGN CALCULATION Document
Title:
FCC 3 - containers for fresh fuel assemblies - Stacking behaviour NON-PROPRIETARY VERSION
Subject:
FCC 3 - containers for fresh fuel assemblies - Stacking behaviour This document is validated through an electronic workflow. Validation dates are stored inside the Electronic Documentation Management system.
Ind.: A Status: BPE Date: 2022-05-13 Modif./Obs.: First Issue Issuer Technical Reviewer Primary Author EDM classification: ADV-AUT ORT: TS00820 Safety Related: YES Responsible: DTIML-F Issuing entity: FFP Expo Control: DOCUMENT NUMBER TRA Goods labeled with "Al not equal to N" are subject to European or German export authorization D02-ARV-01-186-616 en I PUBLIC I when being exported within or out of the EU. Goods labeled with "ECCN not equal to N or EAR99" are subject to US re-export authorization. Even without a labe l, or with label *AL:N" or "ECCN:W or "ECCN:EAR99", authorization may be required due to the final whereabouts and purpose for which the goods are to be used.
No. D02-ARV-01-186-616 framatome NON-PROPRIETARY VERSION REV. A PAGE 2 / 41 REVISIONS IND ISSUE DATE SECTION PURPOSE OF THE REVISION REV Original issue, based on previous note PVED DC 03 0222 rev. A incorporating the following ililll°f modifications:
S9 welds updated A See cover page - S8 weld modelled continuously,
- Addition of study of S 13 weld of the handling box,
- Change to 2 stacking levels to reflect the requirements in Chapter 1.7,
- Incorporation of more penalising criteria in CM66 code z
z
()
()
UJ z
<(
No. D02-ARV-01-186-616 framatome NON-PROPRIETARY VERSION REV. A PAGE 3 / 41
SUMMARY
The acceptability of the stacking of containers for 12 foot assemblies (FCC3) is checked in accordance with CM66 code .
The stacking situation applied is 2-level stacking, with full containers (lower container supports weight of a container), as this situation corresponds to the stacking limit in Chapter 1.7 of this safety analysis report.
Under the terms of the CM66 code, the situation considered is a "normal operation" situation; the weighting coefficient of 1.33 on the dead weight of the containers is taken into account.
The welds are modelled with the follow~ assumptions: the longitudinal S8 weld is a seam weld and the S9 welds have a length o..-nm.
The reinforcement plates for the upper handling lugs are modelled with a contact condition between them and the boxes.
The analysis of the stresses in the shell structures and the welds presents the following margins:
- For the structures, the minimum margin isllll located on the handling box by the apertures.
- For weld S9, the minimum margin is -located on internal side 2 of the "large" handling boxes.
z
- For weld S8, the minimum margin is - located on the internal side of the "small" z
()
handling boxes.
()
UJ
- For weld S14, the minimum margin is - located on side 2 of the "large" handling boxes.
z
<(
boxes .
No. D02-ARV-01 -186-616 framatome NON-PROPRIETARY VERSION REV. A PAGE 4 / 41 TABLE OF CONTENTS
- 0. REFERENCES 6
- 1. INTRODUCTION 7
- 2. GEOMETRIC DEFINITION OF FCC3 CONTAINER 8
- 3. FINITE ELEMENT MODELLING OF THE FCC3 CONTAINER 10 3.1. Mesh 10 3.2. Materials and masses 10 3.3. Boundary conditions and stresses 11
- 4. ANALYSIS RULES AND CRITERIA 13
- 5. PRESENTATION OF CALCULATION RESULTS 14 5.1 . Container distortions 14 5.2. Equivalent stresses in the shell structures 14 5.3. Equivalent stresses in the welds 15
- 6. ANALYSIS OF FCC3 CONTAINER 16 z
z
()
6.1 . Analysis of shell structures 16
()
UJ 6.2. Weld analysis 16 z 7. CONCLUSION 18
<(
LIST OF APPENDICES Appendix A: Model Appendix B: Finite element calculation results Appendix C: Method for analysis of welded joints
No. D02-ARV-01-186-616 framatome NON-PROPRIETARY VERSION REV. A PAGE 5 / 41 LIST OF TABLES Table 1: Characteristics of materials 10 Table 2: Maximum equivalent stresses in the shell structures 15 Table 3: Maximum equivalent stresses in the welds 15 Table 4: Analysis of zones subject to loading in stacking - shell structures 16 Table 5: Weld analysis 17 LIST OF FIGURES Figure 1 : Welds S9 8 Figure 2: Welds S8 8 Figure 3: Handling box of an FCC3 container Weld identification 9 z
z
()
()
UJ z
<(
No. D02-ARV-01-186-616 framatome I NON-PROPRIETARY VERSION I REV. A PAGE 6 I 41
- 0. REFERENCES
[1] Safety analysis report for FCC3 packaging - DOS-18-016471
[2] Note FFP D02 ARV 01 186 614 rev. A: Container for 12 foot assembly - Checking dimensions of lifting attachments - Lifting situation
[3] Drawing of the upper she 11 - 12 foot mode I : 229 K 0110
[4] Drawing of the lower she I I - 12 foot model: 229 K 0105
[5] IAEA regulations on the safe transportation of radioactive materials- lAEA SSR 2018 edition
[6] CM66 Code Rules for calculation of steel structures
[7] Standard NF EN 10025 Hot-rolled products of non-alloy structural steels
[8] SYSTUS' program, version 2019 (21 .0)
Framatome note NEER-F DC 10296 revision I SYSTUS' software: Summary report on physical verification and validation z
z
()
()
UJ z
<(
No. D02-ARV-01-186-616 framatome NON-PROPRIETARY VERSION REV. A PAGE 7 / 41
- 1. INTRODUCTION This note covers the dimensioning of the FCC3 container in stacking conditions.
Stacking conditions are defined by Article 723 of IAEA regulations SSR-6 of 2018 (reference
[5]): it must be demonstrated that the container can withstand a compressive force equal to five times the maximum weight of the package for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
However, the number of levels of stacking for the FCC3 container is limited by the requirements in Chapter 1.7 of the safety analysis report which allows a maximum of 2 levels. Stacking behaviour is therefore verified for 2-level stacking with maximum package mass: stacking of two full containers where the dead weight of a single container is supported by the one below.
The acceptability of the stacking of FCC3 containers for 12 foot assemblies is checked in accordance with CM66 rules in reference [6].
This document takes account of a change concerning lengths of weld beads between the handling boxes, the reinforcing angle bar and the upper shell of the container: longitudinal weld S8 is a seam weld and the S9 weld has lengtrllllmm.
These calculations are performed using SYSTUS' software[8].
z z
()
()
UJ z
<(
No. D02-ARV-01-186-616 framatome NON-PROPRIETARY VERSION REV. A PAGE 8 / 41
- 2. GEOMETRIC DEFINITION OF FCC3 CONTAINER This paragraph provides details of the dimensions considered for modelling (see paragraph 3):
- With regard to the upper shell (excluding welds), the reference used is the drawing in reference [3].
- For welds on the upper handling boxes, the dimensions considered are presented below,
- For the lower shell, the reference is the drawing in reference [4].
For each upper handling box, there are 4 S9 welds as shown in Figure 1.
S9 external z
z
()
()
The lengths of the external and internal S9 welds are those on the drawing of the upper shell noted in Chapter 1.4-1 of the safety analysis report and are equal to mm.
However, the S8 weld is a seam weld for its horizontal section and the vertical return as shown in Figure 2.
Figure 2: Welds S8 For conservative purposes, the vertical return of the S8 weld is not taken into account in the modelling.
The welds are identified as follows in the drawing in reference [3]:
- internal/external S9 welds: one-sided, between each lifting box and the two angle bars in L shape , on each side of them. There are therefore 4 welds per box with a-mm apothem (see Figure 3).
No. D02-ARV-01-186-616 framatome NON-PROPRIETARY VERSION REV. A PAGE 9 / 41
- S8 welds: one-sided and continuous, between the end edges of each lifting box and the upper shell, in the longitudinal direction. There are 2 beads per box with .anm apothem (see Figure 3).
- S14 welds: this is a set of 2 x 8 two-sided discontinuous weld beads, with allllmm apothem, connecting the upper shell to two sides of each circumferential reinforcement angle b~ositioned at one end of the lifting box. The length of each discontinuous bead is.mm except for the 2 x 2 located close to the S8 welds, which are longer at
.mm.
- Weld S13: this is a seam weld between the lower part of the edge of the reinforcement and the handling box on its internal surface on the side of the hole used for lifting the container.
In order to allow good evacuation of residual water that gets inside the handling boxes, an evacuation hole is also present under the external S9 weld.
z PROPRIETARY PICTURE z
()
()
UJ z
<(
Figure 3: Handling box of an FCC3 container Weld identification The modelling of the reinforcements is used in order to take account of the single weld on the lower part of the reinforcement between it and the handling box.
Finally, the asymmetry of the handling boxes (long box at top/short box at bottom) is taken into account in the modelling.
No. D02-ARV-01-186-616 framatome NON-PROPRIETARY VERSION REV. A PAGE 10/41
- 3. FINITE ELEMENT MODELLING OF THE FCC3 CONTAINER 3.1. Mesh The finite element model of the FCC3 container (Figure A. 1) is updated using the container drawings and the CAD is presented Figure A. 2.
The mesh of the handling box takes account of:
- The reinforcement plate welded at the lower section,
- The water drainage openings.
The mesh of the handling box, upper shell and reinforcement angle bars was refined with element size aboutllnm.
To model welds (S9, S8 and S14), element with stiffness, type - in the SYSTUS' ,link rigidly the nodes belonging to elements at the location of the weld bead. The S9, S8 and S14 welds studied are represented in Figure A. 3. For weld S13, the nodes of the reinforcement plate and the lifting box positioned locally at the weld bead are merged. Figure A. 4 presents weld S13.
The bolts connecting the lower and upper shell are modelled by beams. Their distribution is taken from the drawing of the lower shell noted in Chapter 1.4-1.
The distribution of thicknesses over the structure is shown in Figure A. 5.
z z
()
()
UJ 3.2. Materials and masses The shells of the containers are made of z The attachment bolts of the two shells are made of
~ The operating temperature is between -20°C and - There are no significant variations in mechanical characteristics over this temperature range, relative to 20°C, so the mechanical characteristics applied are those for 20°c.
The mechanical characteristics are taken from the lifting note (reference [2]) and shown in Table 1.
Young's modulus [MPa]
Poisson's ratio[-] PROPRIETARY TABLE Yield strength, Rpo,2 [MPa]
Tensile strength, Rm [MPa]
Table 1: Characteristics of materials Note: (*) these characteristics are taken from standard[?].
The total mass of a loaded FCC3 container, in accordance with Chapter 1 .4 of the safety analysis report, is 4,385 kg distributed over:
- The upper shell -
- Thelowershell-
- Internal equipment-
No. D02-ARV-01-186-616 framatome NON-PROPRIETARY VERSION REV. A PAGE 11/41 Note: In the finite element model, the element densities forming the structure are calibrated to obtain the exact masses indicated.
The yield strength of the weld beads, as it needs to be greater than that of the material supporting them, is taken for conservative purposes as equal to the yield strength of the steel of the container.
3.3. Boundary conditions and stresses This note covers stacking of the whole FCC3 container. The requirement of the standard, reference [5], is represented by:
- A stack of six containers, i.e. the weight of five containers of type FCC3 stacked on the modelled one and supported on its four lifting boxes, plus the dead weight of that one,
- The equivalent of 13 kPa multiplied by the vertically projected area of the package.
The force generated by the weight of five containers is greater than the force obtained by multiplying the pressure of 13 kPa by the projection area.
However, the number of levels of stacking for the FCC3 container is limited by the requirements in Chapter 1. 7 of the safety analysis report which allows a maximum of 2 levels.
Stacking behaviour is therefore verified for the situation required by Chapter 1.7, i.e. 2-level stacking of containers with maximum load: stacking of two full containers where the dead weight of a single container is supported by the one below.
z z
()
Only one container is shown . The loading for this container consists of:
()
w
- Its own full weight (permanent load),
- The full container weight located above (permanent load).
z In the terms of the CM66 code (reference [61), the situation considered is a situation referred
<( to as "normal operation".
The code requires use of a weighting coefficient to be taken into account for these 2 types of load: 1,33 for permanent loads.
The weight of the top container is modelled by a pression distributed over the top horizontal surface of the four lifting boxes effectively in contact with the base pads of the non-modelled container (the pads are not supported in contact by the whole of the handling boxes and for FCC3 the boxes are asymmetrical).
The loading conditions for stacking are presented in Figure A. 6, Figure A. 7 and Figure A. 8.
The modelled container is supported by its base pads. These are not modelled. It is therefore the lower surface of the rail that is blocked (UZ=O) over one length equal to that of the pads, about.mm.
Contact and stabilisation conditions of the finite element model are presented in Figure A. 9.
The flanges between the lower and upper half-shells are considered to be bonded.
The upper handling boxes are welded (weld S8) onto the upper half-shell of the container.
However, the weight of the top container leads to a contact imposed between the handling boxes and the upper shell. This contact is considered to be linear and is shown in Figure A.
10.
In order to take account of this contact, two types of contact conditions are considered:
- "Sliding" contact: radial coupling by opposite nodes: under this assumption, even if the loading studied is compressive and brings the metal sheet of the lifting box into contact
No. D02-ARV-01-186-616 framatome NON-PROPRIETARY VERSION REV. A PAGE 12 / 41 with the metal sheet of the container, the coupling between the opposite nodes, located on the edges of the box, takes place only in the radial direction,
- "Adhesive" contact: assumption of bonding between sheets in contact without relative displacement: in this case, a coupling of the three displacements is required between the nodes of the box and of the half-shell located on the edges of the box.
These 2 contact assumptions must encompass the reality with sheets that need to slide over each other with friction.
Non-linear and elastic calculations are performed using the in the SYSTUS' software.
z z
()
()
UJ z
<(
No. D02-ARV-01-186-616 framatome NON-PROPRIETARY VERSION REV. A PAGE 13/41
- 4. ANALYSIS RULES AND CRITERIA The applicable regulation is that concerning safe transport of radioactive material, reference
[5], providing the general requirements concerning the packages.
The analysis of the containers carried out in this study is concerned particularly with the strength of the sheets of the two half-shells, the bases and the lifting boxes, as well as the welded joints on the latter.
The connecting bolts of the half-shells are not under load because compressive loading is taken up by the contact of the connecting flanges between shells.
The rules for analysis provided by the CM66 code (reference [61) are applied, i.e. :
- For plates: erm + err ~ ae ,
- For welded joints: a eq ~ a 2 ae (See Appendix C for determination of a eq)-
Where :
- erm + err : equivalent membrane plus bending stress,
- <Yeq : equivalent Von Mises stress,
- ae: minimum yield strength of material (base metal for welds),
- a: coefficient of reduction, function of groove depth "a" of the weld bead, taking the following values:
z z
() o a= 1 fora~ 4mm,
()
UJ o a= 0,8. (1 + 1/a) fora> 4mm.
The minimum dimensions of the groove section for the types of beads concerned are as z
follows, according to drawing [3]:
<(
- Circumferential welds of the angle bar, S14:
- Longitudinal welds of the box, S8:
- Internal and external welds between box et angle bar, S9: _ ,
- Longitudinal welds of the box with the reinforcement plate, S 13:
- - o n s "a " , the coefficient of reduction a Reminder: The weighting coefficients for permanent loadings for structures referred to as "in normal operation" in the CM66 code (reference [61) are used. It equals 1.33.
No. D02-ARV-01-186-616 framatome NON-PROPRIETARY VERSION REV. A PAGE 14 / 41
- 5. PRESENTATION OF CALCULATION RESULTS For stacking load, the distribution of displacements and of equivalent Von Mises stresses in the FCC3 container middle, top and bottom skin are presented, for both sliding and adhesive contact conditions.
5.1. Container distortions The norm for the displacements is presented in Figure 8 . 1 and Figure 8 . 2 for geometry deformed with an amplification of 50.
For the weighted-tackinsituation with two levels of full containers, the maximum norm of the displacements is in sliding contact a n d - - in adhesive contact, and is located on the contact zone o e top container on "sma'n"boxesat the handling aperture.
5.2. Equivalent stresses in the shell structures The equivalent Von Mises stresses are presented for the middle skin and for the lower and upper skins, for geometry deformed with amplification of 50:
- 2-level stacking, full containers, sliding contact condition, equivalent Von Mises stresses in Figure 8. 3, Figure 8. 5, Figure 8 . 7, Figure 8. 12 and Figure 8. 14.
- 2-level stacking, full containers, adhesive contact condition, equivalent Von Mises z
stresses in Figure 8 . 4, Figure 8 . 6, Figure 8 . 8, Figure 8 . 13 and Figure 8 . 15.
z
()
()
UJ The assumption has minimal influence on the contact condition between the handling box and the half-shell.
z The maximum equivalent Von Mises stresses are local, in the following positions:
.:.;
- In the handling boxes by the apertures (see Figure 8. 9),
<(
- On the upper shell at the contact between the handling box and the shell, at the end of the linear contact (see Figure 8 . 10),
- In the boxes close to the S9 welds, on internal side 2 (see Figure 8. 11 ).
The stress values are presented in Table 2.
No. D02-ARV-01-186-616 framatome NON-PROPRIETARY VERSION REV. A PAGE 15 / 41 Contact Equivalent Von Mises stresses (MPa)
Zone Half-shell Membrane Membrane + bending Box Handling box Sliding aperture Bonding Sliding Upper shell Bonding PROP RI ETARY TABLE Box close to Sliding internal S9 welds Bonding Sliding Reinforcing angle bars Bonding Table 2: Maximum equivalent stresses in the shell structures 5.3. Equivalent stresses in the welds The equivalent membrane and membrane + bending stresses calculated by the method defined in Appendix Care presented in Table 3.
Contact Equivalent Von Mises stresses (MPa) z Weld Half-shell Membrane Membrane + bending z Box
()
()
w Sliding S9 Bonding z
Sliding
.:.; S8
<( Bonding PROPRIETARY TABLE Sliding S14 Bonding Sliding S13 Bonding Table 3: Maximum equivalent stresses in the welds
No. D02-ARV-01-186-616 framatome NON-PROPRIETARY VERSION REV. A PAGE 16/41
- 6. ANALYSIS OF FCC3 CONTAINER 6.1. Analysis of shell structures The analysis of the stresses in the shells is carried out again in the zones subject to the highest loads in stacking.
The analysis of the equivalent Von Mises membrane + bending stresses is evaluated at the centre of gravity of the elements in accordance with paragraph 4.
The allowable stress , equal to the minimum elastic stress is - ( s e e §3.2).
Table 4 presents the analysis of the membrane + bending stresses as well as the margin obtained for the two contact cases .
Membrane+
Contact Criterion bending stress Zone Half-shell Margin Box CTm + (Tf Ge (MPa)
(MPa)
Handling box Sliding aperture Bonding Sliding Upper shell Bonding z
PROPRIETARY TABLE Box close to Sliding z
()
()
internal S9 welds Bonding w
Sliding Reinforcing angle bars Bonding z
Table 4: Analysis of zones subject to loading in stacking - shell structures
<(
For weighted full two-level stacking, the minimum margin is -located on the handling box by the apertures.
The criteria are respected for the shell structures.
6.2. Weld analysis The repeated weld analysis concerns the welds in the stacking zone (loading zone), i.e. welds S9, S8 and S14 as well as weld S13 between the handling box and the reinforcement plate.
The weld beads in the stacking zone are fillet welds with partial penetration. The stresses are calculated in the weld bead groove section drawing based on the forces and moments calculated at the centre of gravity of the mesh along the length of the weld according to the methodology described in Appendix C of this document.
As weld S9 is very short - the stresses have been evaluated over the length of the weld by implementing an average of the individual stresses.
Table 5 presents the analysis of the maximum stress values as well as the margin obtained for the two contact cases and for each of the four welds.
No. D02-ARV-01-186-616 framatome NON-PROPRIETARY VERSION REV. A PAGE 17/41 Contact Stress Criterion Zone Half-shell Cfeq a2 a e Margin Box (MPa) (MPa)
Sliding S9 Bonding Sliding S8 Bonding PROP RI ETARY TABLE Sliding S14 Bonding Sliding S13 Bonding Table 5: Weld analysis The assumption has the greatest influence on the contact condition between the handling box and the half-shell for weld S8 and to a lesser extent for weld S9.
The minimum margin for weld S9 is located on internal side 2 of the "large" handling boxes.
The minimum margin for weld S8 is - located on the internal side of the "small" handling boxes.
The minimum margin for weld S14 is -located on side 2 of the "large" handling boxes.
z z
u The minimum margin for weld S13 is-located on the weld of the "small" handling boxes.
u UJ All welds analysed comply with the criterion.
z
<(
No. D02-ARV-01-186-616 framatome NON-PROPRIETARY VERSION REV. A PAGE 18/41
- 7. CONCLUSION The acceptability of the stacking of containers for 12 foot assemblies is checked in accordance with CM66 code.
The stacking situation applied is 2-level stacking, with full containers, in accordance with Chapter 1.7 of the safety analysis report.
Under the terms of the CM66 code, the situation considered is a "normal operation" situation; the weighting coefficient of 1.33 on the dead weight of the containers is taken into account.
This document takes account of the following lengths of weld beads between the lifting boxes, the reinforcing angle bar and the ~ h e l l of the container: longitudinal weld S8 is continuous and weld S9 has length o f -. The reinforcement plates for the upper handling lugs are modelled with a contact condition between them and the boxes.
The analysis of the stresses in the shell structures and the welds presents the following margins:
- For the structures, the minimum margin is - located on the handling box by the apertures.
- For weld S9, the minimum margin i s . located on internal side 2 of the "large" handling boxes.
- For weld S8, the minimum margin is - located on the internal side of the "small" handling boxes.
z z
()
- For weld S14, the minimum margin is - located on side 2 of the "large" handling
()
UJ boxes.
<(
No. D02-ARV-01-186-616 framatome NON-PROPRIETARY VERSION REV. A PAGE 19 / 41 z
z
()
()
UJ Appendix A: Model z
<(
No. D02-ARV-01-186-616 framatome NON-PROPRIETARY VERSION REV. A PAGE 20 / 41 PROPRIETARY FIGURES z
z
()
()
UJ z
<(
No. D02-ARV-01 -186-616 framatome I NON-PROPRIETARY VERSION I REV. A PAGE 21 / 41 PROPRIETARY FIGURES z
z
()
()
UJ z
<(
No. D02-ARV-01-186-616 framatome NON-PROPRIETARY VERSION REV. A PAGE 22 / 41 PROP RI ETARY FIGURES z
z
()
()
UJ z
<(
No. D02-ARV-01-186-616 framatome NON-PROPRIETARY VERSION REV. A PAGE 23 / 41 PROPRIETARY FIGURES z
z
()
()
UJ z
<(
No. D02-ARV-01-186-616 framatome NON-PROPRIETARY VERSION REV. A PAGE 24 / 41 PROPRIETARY FIGURES z
z
()
()
UJ z
<(
No. D02-ARV-01-186-616 framatome NON-PROPRIETARY VERSION REV. A PAGE 25 / 41 z
z
()
()
UJ Appendix B: Finite element calculation results z
<(
No. D02-ARV-01-186-616 framatome NON-PROPRIETARY VERSION REV. A PAGE 26 / 41 PROPRIETARY FIGURES z
z
()
()
UJ z
<(
No. D02-ARV-01-186-616 framatome NON-PROPRIETARY VERSION REV. A PAGE 27 / 41 PROPRIETARY FIGURES z
z
()
()
UJ z
<(
No. D02-ARV-01-186-616 framatome NON-PROPRIETARY VERSION REV. A PAGE 28 / 41 PROP RI ETARY FIGURES z
z u
u UJ z
<(
No. D02-ARV-01-186-616 framatome NON-PROPRIETARY VERSION REV. A PAGE 29 / 41 PROPRIETARY FIGURES z
z
()
()
UJ z
<(
No. D02-ARV-01 -186-616 framatome I NON-PROPRIETARY VERSION I REV. A PAGE 30 / 41 PROPRIETARY FIGURES z
z
()
()
UJ z
<(
No. D02-ARV-01-186-616 framatome NON-PROPRIETARY VERSION REV. A PAGE 31 / 41 PROPRIETARY FIGURES z
z
()
()
UJ z
<(
No. D02-ARV-01-186-616 framatome NON-PROPRIETARY VERSION REV. A PAGE 32 / 41 PROPRIETARY FIGURES z
z
()
()
UJ z
<(
No. D02-ARV-01-186-616 framatome NON-PROPRIETARY VERSION REV. A PAGE 33 / 41 PROPRIETARY FIGURES z
z
()
()
UJ z
<(
No. D02-ARV-01-186-616 framatome NON-PROPRIETARY VERSION REV. A PAGE 34 / 41 z
z
()
()
UJ Appendix C: Method for analysis of welded joints z
<(
No. D02-ARV-01-186-616 framatome NON-PROPRIETARY VERSION REV. A PAGE 35 / 41
- 1. PURPOSE The purpose of this Appendix is to specify the method for analysis of welded joints. All the welds dealt with are fillet welds with partial penetration identified in Figure A. 3 and Figure A.
4 (welds S13, S14, S8 and S9).
The stresses are evaluated on the "groove section" drawing (see Figure C.1):
- normal stress er_j_ ,
- tangential stress r _j_ , which is the component perpendicular to the weld axis,
- tangential stress r 11 , is the component parallel to the weld axis.
The stresses cr_j_ r_j_ r 11 are determined using external stresses.
Groove section drawing z
z
()
()
w z
<{
Figure C.1: Components of stresses in the groove section of a fillet weld
No. D02-ARV-01-186-616 framatome NON-PROPRIETARY VERSION REV. A PAGE 36 / 41
- 2. CALCULATION OF STRESSES IN THE WELDS BASED ON EXTERNAL STRESSES 2.1 Forces taken from SYSTUS' calculation The generalised forces (forces per unit of length of centreline) in the shell elements taken from SYSTUS' (reference [8]) are:
- NX, NY : membrane forces,
- NXY : shear force,
- MX, MY : bending moments,
- MXY : torsional moment.
The storage sequence for the six individual force components in the SYSTUS results file is:
NX, NXY, NY, MX, MXY, MY.
These forces, calculated at the center of the element, are expressed in the specific local reference base for each element (Figure C.2). Using the current version of SYSTUS' (called "new data structure"), for element of linear spatial shell type, this reference frame is variable and depends on the sequence of definition of the nodes of each element (N1 to N4 in Figure
~r;)NY C.2).
L3 MX1t2 z
z
()
()
UJ I
I I
z I I
.:.; I
<( I I
I /
II
- Coques :minces : 2003, 2203, 2204, 2004 Figure C.2: Identification of local axes of thin shells in SYSTUS'
No. D02-ARV-01-186-616 framatome NON-PROPRIETARY VERSION REV. A PAGE 37 / 41 It should be noted that the "shells" convention used by SYSTUS' to identify the components of moment is different to the usual RdM convention (SYSTUS': MX moment that produces a stress CYx in the element; RdM: MX moment around X axis).
2.2 For a fillet weld For fillet welds (S13, S8 and S9), the forces taken from the SYSTUS' finite element calculation are oriented according to the specific reference frame of each weld for which stresses need to be calculated (Figure C.3).
X e
Figure C.3: Reference frame of local axes used for calculation of stresses in the fillet welds z
z
()
Each force (SYSTUS' notes) produces the following stresses:
()
UJ
- Force NX:
INXI z CT.1 =--
a\/2.
<( INXI T .1 = - -
a\/2.
Tl/ = 0
- Force NY:
(J.L =0 T .1 =0 Tl/ = 0
No. D02-ARV-01-186-616 framatome NON-PROPRIETARY VERSION REV. A PAGE 38 / 41
- Force NXY:
CT1. =0 TJ. =0 INXYI T11 = - -
a For moments, the distribution is assumed to be linear along the length of the groove section.
- Moment MX (turns around the Y axis):
6IMXI (Tl. =~
T1. = 0 Tl/ = 0
- Moment MY (turns around the X axis):
z 0"1. =0 z
()
T1. =0
()
UJ Tl/ = 0
- Moment MXY :
z 0"1_ =0
<(
T1_ =0 6IMXYI Tl/ = a2 Lastly, the stresses in the groove section drawing are:
INXI 6IMXI
= - - + a../2 0"1_
a INXI T1_ =--
a../z INXYI 6IMXYI T11 = - - + 2 a a For the analysis, these stresses are divided into two types:
- They are considered element by element for the "long" seam welds (S8, S13),
- For shorter welds (S9), the stresses may be averaged over the total length of the bead.
No. D02-ARV-01-186-616 framatome NON-PROPRIETARY VERSION REV. A PAGE 39 / 41 2.3 For angle bars The angle bar is assumed to be more rigid than the shell (which is true because it has a thickness 2 times that of the shell): in this way the forces on the welds are assumed to be transmitted by the angle bar.
The load set is transposed from the center of the plate, which represents the wing of the angle bar modelled toward the median point between the two welds at the base of the angle bar.
Compared to Figure C.4 (in which the forces are expressed in the reference frame of the welded joint instead of in the SYSTUS' reference frame), this is equivalent to moving from the SYSTUS' calculation point "E" to point "M", in the middle of the angle bar. Lastly, after forces and moments transfer, the forces are assumed to be taken up in equal parts by the two welds which are located at the base of the angle bar.
AX I
I I
.?! z. b xy,-,-"_,,,.
z z
u u
w
)C E
C
~!
(7.l..
z
<(
Figure C.4: Reference frame of local axes used for calculation of stresses in the fillet welds In the SYSTUS' local reference frame of the shell element that represents the vertical baseplate of the angle bar, the correlations for the transition are as follows, applying the convention of signs for components of forces and moments provided in paragraph 2.1 above:
- MXM = MXE + NX(e - b)/2 (turns around Y)
- MYM = MYE + NY(e - b)/2 (turns around X)
- MXYM = MXYE The stresses are calculated in relation to the force load set calculated at point "M" using SYSTUS' notations:
- Force NX: each weld takes NX/2 if the force NX is tension (NX > 0). A compression force (NX < 0) is taken up by contact on the shell. It therefore does not apply load to the weld beads.
~~ = max( 2:~;o) r ~ = max (
2:~; 0)
Tl/ = 0
No. D02-ARV-01-186-616 framatome NON-PROPRIETARY VERSION REV. A PAGE 40 / 41
- Force NY: this force only creates a longitudinal normal stress.
lT.1 =0 T.1 =0 Tl/ = 0
- Force NXY :
lT.1 =0 T.1 =0 INXYI Tl/ = ~
- Moment MX: bending moment may be modelled as 2 opposing forces F applied at the 2 beads; which fits the case of the force NX applied to a fillet weld with:
MXM MXE + NX(e - b)/2 F=--=-------
e e z
Hence stresses:
z
() IFI IMXE I + INX(e - b)/2 1 a'12. = ae'12.
()
w a-.1 =
_ IFI _ IMXE I + INX(e - b)/21 z T .1 - a'12. - ae'12.
.:.; Tl/ = 0
<(
- Moment MY: this moment only creates a longitudinal normal stress.
lT.1 =0 T.1 =0 Tl/ = 0
- Moment MXY :
lT.1 =0 T.1 =0 IMXYI T11 = - -
ae Lastly, the stresses in the groove section drawing are:
NX ) IMXEI + INX(e - b)/ 21 0-.1 = max ( r,;;; 0 + 17>
2av2 aev2 NX ) IMXEI + INX(e - b)/ 21 T .1 = max ( 17>; 0 + r,;
2av2 aev 2 INXYI IMXYI T11 = - - + - -
2a ae For the analysis of the S14 welds, the stresses are considered element by element.
No. D02-ARV-01-186-616 framatome NON-PROPRIETARY VERSION REV. A PAGE 41 / 41 2.4 CALCULATION OF EQUIVALENT STRESS For the welds, the formula for calculation of equivalent stress, in accordance with reference [6]
is:
Cleq = al+ 1,8(r1 + r})
z z
()
()
UJ z
<(