Experimental Mechanics-overview

1. Experimental Mechanics-overview Module lectures: Professor Janice Barton janice@soton.ac.uk B13 4087 Professor Fabrice Pierron f.pierron@soton.ac.uk B13 3061 Professor Simon Quinn sq1@soton.ac.uk – B15 2023 Mr Peter Fuller Instron Mr Alan Fulbrook Vishay Dr Richard Burguete NPL Ms Eszter Szigeti Airbus Dr Dave Hollis LA Vision Dr Duncan Crump dac400@soton.ac.uk Dr Andy Robinson afr103@soton.ac.uk TSRL Dr Lloyd Fletcher L.C.Fletcher@soton.ac.uk Mr Vishnu Seelan P.Jayaseelan@soton.ac.uk

2. Experimental Mechanics-Introduction • Provide a brief overview of the module • Describe the module structure and organisation • Describe the assessment procedure • Describe the laboratory sessions Notes and other materials will be available on the Blackboard site and on http://www.camfit.fr/EMcourse/index

3. What is experimental mechanics? • Investigation by experimental means of the mechanical behaviour of engineering systems subjected to load • System can be a structure, a material, soft matter such as human tissue, a fluid-structure coupling • Measurement system is used to capture a quantity that describes the system’s behaviour • Seek information on deformation and the mechanical strain • Experimental data required to validate numerical models • Derivation of failure parameters by deriving the stresses from the strains and derivation of material constitutive relationships

4. Aims and objectives • Provide an in-depth understanding of experimental mechanics approaches • Introduce students to testing procedures • Provide detailed knowledge of the application of point measurement techniques such as electrical resistance strain gauges. • Provide a detailed knowledge of modern full field techniques such as Thermoelastic Stress Analysis (TSA), Digital Image Correlation (DIC), Grid method. • Understand how the data from experimental techniques are manipulated to validate numerical models. • Understand the effect of data smoothing and how to apply smoothing approaches effectively

5. Timetable

6. Load cell Crosshead Testing machine Screw actuators Extensometer Grips Specimen Base

7. Stress-strain curve

8. Test machines • Three categories based on load generation: • Hydraulic • Mechanical • Electrodynamic • Control system for load and displacement application – usually a servo system • Detailed lecture from Peter Fuller of Instron on test machines

9. Electrical resistance strain gauges

10. Electrical Resistance Strain Gauges • Basic experimental mechanics sensor • Used in virtually every engineering application for measurement and monitoring purposes • Lecture from Anton Chitty of Vishay Precision Group Micro-Measurements

11. Full-field techniques for strain measurement • Full-field techniques describe a category of approaches where a field of data is collected as opposed to the single point reading extracted from a strain gauge. The techniques can be broadly divided into three categories: • White light techniques • Coherent light techniques • Infra-red techniques

12. Digital Image Correlation – Janice/Dave Hollis

13. Digital Image Correlation

14. Grid technique- Fabrice Phase Mean intensity Contrast pitch • Professor Fabrice Pierron Unidirectional grid Bidirectional grid Unidirectional grid

15. Coherent light –ESPI- Fabrice

16. Photoelasticity- Richard Burguete Dr Richard Burguete from NPL in application session

17. Infra-red techniques -Janice

18. Laboratory sessions • The details for each laboratory class are provided on a separate sheet. • During each laboratory session you will collect data using each of the techniques described. • The data will be uploaded to \\soton\ude\courses\SESG6031. • All software necessary for this module is also stored in the same space. • To access this space please put the link into windows explorer and you will be then asked for your Southampton user name and password. If accessing from a home PC through a VPN connection,you may be asked for your Southampton user name and password. • Full descriptions of the laboratory classes are provided in the separate hand-out. • The laboratory sessions are done in groups – Your group number (1-6) is on your badge and the attendance list. • A separate timetable for the laboratory sessions is provided.

19. Laboratory sessions

20. Test specimens

21. Brazilian Disc

22. Assignment (for those seeking credit) • A detailed analysis of the data collected in the laboratory classes will be carried out. • The mechanical properties of the aluminium alloy material that was tested is derived using the different experimental techniques. • The stresses and strains in the disc will be derived using each technique and the values from each technique compared. • The virtual fields method will be used extract the material properties from the data from the discs obtained using the white light techniques. • Full details of the assignment are given on a separate hand-out and in the wrap-up session at the end of the week. • The assignment is to be up loaded on the blackboard site and the file name should be firstname_lastname_EM. The deadline is Friday 11th May 2018

23. Certificate of attendance • All will receive a certificate of attendance • UoS Credit can be only be awarded if students are registered at Southampton. • This is open to all overseas students and EU nationals studying at a UK University after registering as a visiting student. • Tier 4 visa requirements means that non EU nationals domicile in the UK cannot register as a visiting student . • If you wish to register as a visiting student and receive credit – talk to me after the lecture – form filling is required! • Anyone wishing to receive feedback on the assignment is welcome to complete the assignment and email and we will send comment and give an indicative mark.