Revised design of the LBNF warm cryostat A
Revised design of the LBNF warm cryostat A. Catinaccio CERN EP-DT-EO LBNF Discussion CERN, 5 th & 6 th of December 2016 https: //indico. cern. ch/event/571287/ 05/12/2016 Page 1
Introduction • Design revisions since last review of May 2015 • Calculations, Assembly Process and CAD Models available • Conclusions and Work ahead Page 2
Original Design Concept Presented at the review of May 2015 http: //indico. cern. ch/event/395238/ 3
18. 096 m Original Design Concept Main Structural Frame ~ 40 portals + = Unit Cell (1. 6 m pitch) ~71000 kg Interlink Grid + 10 mm Steel Plate 19. 196 m 1. 6 m Bolted Connection Splice Connection Welded Connection 04/06/2015 Page 4
Original Design Concept 5
Design revisions of the warm structure • Following various optimisations with structural analysis models made by EP/DT-EO New end wall design New floor design New roof design New side wall belts. Tolerance compliant connections New concept of inner warm membrane with stiffened panels Page 6
Main design modifications to the outer warm structure – Improved bracing concept for the load carrying structure – Longitudinal belts design and connections – Roof optimisation and short wall interaction, longitudinal roof beams – Short wall design – Floor design, main connections, support conditions, access holes – Design of additional splices for compatibility with crane/shaft. – Corner design – Main portals and belts access holes (reinforced) – Decoupling warm structure and inner warm membrane – Main connections verification – Access and assembly issues Page 7
Main design modifications to outer warm membrane – Replacing grid with stiffened panels – Allows for material saving, less welding in situ, and easier access for assembly. GRID RIB BOX Page 8
Assembly and model repository • Assembly procedure and tooling (advancing). • Repository with component list detailing mass and dimensions: https: //edms. cern. ch/file/1739475/1/ Weight. Dimension. Vessel. pdf • Stp file available: https: //edms. cern. ch/document/173 8513 Page 9
New design of the outer structure Stp files available: https: //edms. cern. ch/document/1738513 Page 10
Plans for Testing Structural Joints • Collaboration with EPFL Ress. Lab (former Steel Structures Lab), prof. D. Lignos • Tests will be carried out at EPFL Structural Hall • 2’ 000 k. N actuators are available Top Corner rib weld plate Bottom Corner Splice Belt/Column connection Page 8
Contribution Summary • Two full design reiterations from the initial conceptual design • Models for detailed analysis Analytical – – Main portal (Beam models; Shell model; Solid Model) & Numerical Unit Cell (Beam Model; Beam + Shell Model) (ANSYS, SCIA) Studies Global Cryostat Model (Beam models; Beam + Shell Models) Inner Warm Plate & Connections (Detailed solid Sub-models) • Verification according to EUROCODE 3 – ASME BPVC to be re-iterated when required. • Detailed 3 D CAD model & technical drawings • Assembly/Installation studies 04/06/2015 Page 12
Conclusions The analyses have covered • • • Load case combinations • Evaluation against plastic collapse, by linear and non linear analyses (ANSYS, SCIAeng) • Verification done according to EUROCODE 3 Static stress-deflection behaviour Local and global failure criteria: stresses, stability (global and lateral buckling), on main members, inner warm plate, connections, welds, bolts. Work ahead • • • Final design completion process (door, floor supports, assembly, tooling …) Seismic Analysis FEA of connections ASME checks when required Design, FEA, production and testing of main connections Testing prototype concept Page 13
Material Page 14
Analysis: Loading • Static head of LAr: 14 m (~100% filling ratio, ρ=1400 kg/m 3) • Top pressure: 130 mbar to 350 mbar (valve opening) • Weight of members: – Main portal beams: 607 kg/m (HL 1100 -607) – Insulation (800 mm thick): 170 kg/m 2 • Baseline Material: Grade S 460 ML (σy=430 MPa; UTS=530 MPa) Loading corresponding to Unit Cell (pitch 1. 6 m) 04/06/2015 Page 15
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