Update on workshops 18-19th May 2017 FEA workshop: STFC Daresbury D. Butler, W. Tizzano Metal Additive Manufacture Seminar: Manufacturing Technology Centre, Coventry S. Scott, A. Peach

List of presentations (available in engineering design guidelines -> FEA) FEA ‘Best Practice’ (a 30 year personal perspective) The FEA assessment and PSE certification project STFC Best practice survey ISIS TS1 project: Target design and analysis Thermal analysis for Space: Finite Difference vs Finite Element Simulations of laser engineered surface structures for the LHC high-luminosity upgrade Steel structures for compliance with Eurocode 3 Simulation of a bolted frame for the ISIS TS1 project Parametric optimisation for the ISIS target station one project cryogenic moderators Thermal Analysis of the SKA electronics cabinets using Ansys Icepak/Fluent CFD Simulation for Additive Manufacturing Electromagnetic Finite Element Simulations at ISIS

FEA Good practise – Barry Fell Dedicated FEA / CFD machine HPC (multi-core licence) with lots (128 GB) of RAM Simple problems can solve quickly Large problems (2-3 days) don’t monopolise users workstation Real world validation Aim to perform some validation either bench top or full scale Model simplification Physics often uncertain so ok accept large uncertainties Library of validated Materials

FEA Good practise – Barry Fell Library of hand calculations Mathcad documents / template calculations Well documented Centrally accessible and locatable Reporting policy Reports generated for any and all analyses / modelling Aim to avoid searching for …analysis_1…. analysis_n and trying to figure out what it was months after the event Standard FEA / CFD template Initial modelling / hand calcs Verification Qualifications / assumptions / simplifications Conclusions Make it available / accessible!

FEA Good practise – Barry Fell e.g. Roark and Young in Mathcad worksheets

NAFAMS "To promote the safe and reliable use of finite element and related technology" Simulation is a tool for engineers, should not be specialists operating in isolation In the past it was a specialist field due to the computing requirements Assist with CPD and offer a certification of competency in FEA / CFD Entry level Standard level Advanced level

NAFAMS Competencies Professional Simulation Engineer (PSE) skills Assess competency of simulation and modelling Non-package specific 26 areas of competency

NAFAMS – Why? External validation of simulation competency Application for a level of competency in selected areas Does not need to be all 26x Interview Certification awarded at appropriate level Internationally recognised PSE competency tracker a tool for learning Competency statements E.g. MESMkn20 - Define Tresca and von Mises Stress for a 3D stress state Resource references E.g. MESMref20 – Pressure Vessels Design and Practice. S Chattopadhyay, CRC Press, ISBN 0-8493-1369-4 - Chapter 3.2

NAFAMS at STFC STFC trialled with 3x people Plan to roll out to rest of STFC engineering Advanced certification can mentor students Positive experience reported

ISIS TS1 target design and analysis Redesign TS1 target (and other components) to improve neutronic output, without compromising current reliability Good example of what 30 years of design and simulation developments can achieve Heavy water filled vessel for cooling tungsten plates (spallation source) CFD of cooling – 6 m/s water flow ~ 23,000 m/m2 K FEA of vessel and optimisation of front window – maximise neutron beam Mass of material (kg) Current TS1 TS1 Project Reduction Stainless Steel 73.8 8.1 89.0% Tantalum 32.7 6.9 79.0% Tungsten 47.3 46.0 2.8% Total 153.8 61.0 60.3%

ISIS TS1 target design and analysis – PD5500 Had to deviate from standard code for their vessel PD5500 ‘Design by Analysis’ section gives guidance on using ANSYS results, but is not very specific and open to interpretation. In general: Calculate design strength ‘f’ (minimum of 2/3 yield strength or 2/5 UTS) Separate stress results into categories (primary membrane, primary bending, secondary) ANSYS linearised stress results at locations of interest Apply different limits depending on the location and type of stress: Location Type   Stress Category Membrane Bending Membrane + Bending Total Including Thermal General f 1.5f 3f Discontinuity Concentration N/A Note: Limits apply to stress intensity (Tresca criterion)

Conclusions Single, high performance dedicated FEA machine offers STFC benefits Standardised FEA reports including hand calculation Standard templates for standard calculations NAFEMS certification Validation of FEA skills Not package specific so differs from Ansys training which teaches how to use Ansys not necessarily the theory of FEA