Application of FE-analysis in Design and Verification of Bolted Joints According to VDI 2230 at CERN

220 Pages·2017·13.55 MB·English

by  Jørgen Apeland

Application of FE-analysis in Design and
Verification of Bolted Joints According to
VDI 2230 at CERN
Jørgen Apeland
Master of Science in Mechanical Engineering
Submission date: February 2018
Supervisor: Torgeir Welo, MTP
Co-supervisor: Luca Dassa, CERN
Norwegian University of Science and Technology
Department of Mechanical and Industrial Engineering

Application of FEA in Design and Verification of Bolted Joints According to VDI 2230

Preface
This master thesis was written the Fall of 2017 and early 2018, and concludes my degree in
Mechanical Engineering at the Norwegian University of Science and Technology. The master
project has been carried out while being a technical student in the engineering department at
CERN, the European Organisation for Nuclear Research.
The thesis is about how computer simulation tools can be combined with VDI 2230, a
calculation guideline for bolted joints, to achieve quality and productivity rewards in design
and verification of bolted joints. The scope was also to lower the threshold and making it easier
to perform such assessments.
It takes basis in a specific engineering case, which demonstrates the need for improved
knowledge and an analysis strategy. A complete framework with a simplified workflow and
support material is presented and demonstrated. In the end, specific recommendations for the
initial engineering case are given.
The reader is expected to have basic knowledge in mechanics, springs, bolted joints and finite
element analysis. ANSYS Workbench V17.2 has been used for FE-analysis, and Mathcad Prime
V4.0 for engineering calculations.

Genève, 2018

Jørgen Apeland
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MSc Thesis 2018

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Application of FEA in Design and Verification of Bolted Joints According to VDI 2230

Acknowledgements
I would like to thank my CERN supervisors Luca Dassa and Antonio Lafuente for their
guidance, discussions, and thorough feedback during my research. They have been essential for
the initiation and development of the project.
I would also like to thank my supervisor at NTNU, Torgeir Welo, for his contributions and
reviews, and for making this project possible.
The design and analysis office in EN-MME has provided a friendly and international working
environment, and they have provided useful input on user experiences and needs related to
analysis of bolted joints.
Finally, I would like to thank CERN and the Technical Student Programme for establishing a
framework where students can come and take part in cutting edge technology development, and
get practical and valuable experiences in a high competence environment.

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Application of FEA in Design and Verification of Bolted Joints According to VDI 2230

Abstract
This thesis investigates how finite element analysis (FEA) can be used to simplify and improve
analysis of bolted joints according to the guideline VDI 2230. Some aspects of how FEA can
be applied to aid design and verification of bolted joints are given in the guideline, but not in a
streamlined way that makes it simple and efficient to apply.
The scope of this thesis is to clarify how FEA and VDI 2230 can be combined in analysis of
bolted joints, and to present a streamlined workflow. The goal is to lower the threshold for
carrying out such combined analysis. The resulting benefits are improved analysis validity and
quality, and improved analysis efficiency.
A case from the engineering department at CERN, where FEA has been used in analysis of
bolted joints is used as basis to identify challenges in combining FEA and VDI 2230. This
illustrates the need for a streamlined analysis strategy and well described workflow.
The case in question is the Helium vessel (pressure vessel) for the DQW Crab Cavities, which
is an important part of the High Luminosity upgrade of LHC (HL-LHC).
Investigations are performed into prying, a relevant source of non-linear bolt loads and
unpredictable load development, to understand the phenomenon and influence of preload. A
complete analysis framework is then presented, which consist of a streamlined basic workflow,
associated calculation template, details of more advanced verifications, a detailed guide with
best practices and references, examples where the analysis framework has been applied, and a
seminar to educate relevant personnel.
In the end, suggestions and recommendations are provided for a potential revision of the Helium
vessel analysis.
The hope is that this thesis can be used as a resource in analysis of bolted joints using VDI 2230
and FEA, and that it will benefit the engineering department at CERN and other relevant users.

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Application of FEA in Design and Verification of Bolted Joints According to VDI 2230

Sammendrag
Denne oppgaven tar for seg hvordan datasimuleringer (FEA) kan benyttes til å forenkle og
forbedre analyse av boltede forbindelser i henhold til retningslinjene i VDI 2230. Enkelte
aspekter av hvordan FEA kan benyttes for å assistere design og verifikasjon av boltede
forbindelser er omtalt i retningslinjene, men ikke på en strømlinjeformet måte som gjør det
enkelt og effektivt å benytte.
Målet med oppgaven er å redegjøre for hvordan FEA og VDI 2230 kan kombineres, og å
presentere en strømlinjeformet arbeidsflyt. Håpet er dermed å senke terskelen for å utføre slike
kombinerte analyser. Fordelene er forbedret validitet og kvalitet i analysen, samt forbedret
effektivitet i prosessen.
Det er tatt utgangspunkt i en analyse fra ingeniøravdelingen ved CERN, hvor FEA har blitt
benyttet i verifikasjon av boltede forbindelser. Denne er brukt som basis for å identifisere
utfordringer med å kombinere FEA og VDI 2230, og illustrerer behovet for en strømlinjeformet
analyse strategi og detaljert beskrivelse av arbeidsflyten.
Analysen det er tatt utgangspunkt i er en Helium beholder (trykkbeholder) for DQW Crab
Cavities, som er en viktig del av en kommende oppgradering av LHC kalt High Luminosity
LHC (HL-LHC).
En aktuell kilde for ikke-lineære bolt laster og uforutsigbar last utvikling kalt prying er
undersøkt for å forstå fenomenet bedre, samt innvirkningen av forspenning. Et komplett analyse
rammeverk er presentert, som består av en strømlinjeformet arbeidsflyt, tilhørende beregnings
mal, detaljer om mer avanserte beregninger og verifikasjoner, en detaljert guide med «beste
praksis» og relevante referanser, eksempler hvor den foreslåtte arbeidsflyten er benyttet, samt
et seminar for å undervise relevant personell.
Til slutt er spesifikke forslag og anbefalinger for en potensiell revisjon av Helium beholder
analysen gitt.
Håpet er at denne oppgaven kan bli benyttet som en ressurs innen design og verifikasjon av
boltede forbindelser ved bruk av VDI 2230 og FEA, og at den vil være til nytte for
ingeniøravdelingen ved CERN og andre relevante brukere.

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