ACCELERATE Research2Business Online-Workshop: Residual Stress Analysis

Tuesday 9 Mar 2021, 10:00 → 14:05 Europe/Berlin

Zoom

Marc Thiry (HZG)

Residual stresses are mechanical stresses present in a workpiece or a component, which is not influenced by external forces or heat gradients. They are present in nearly all materials and result from deformations, heat treatments or structural changes (phase transformation). Uneven cooling in castings or welds also leads to significant residual stresses.

Residual stresses, superposed by external load during service conditions of the material can lead to premature failure of the components. In other cases, residual stresses are generated on purpose to obtain materials with special features. This technique is called residual stress engineering.

What are the best ways to achieve understanding about residual stress in your materials and components? This workshop will cover both standard laboratory techniques and advanced methods at large scale research facilities. It will showcase how synchrotron radiation and neutrons can, in a non-destructive manner, give insights into residual stress in materials and engineering components. Several techniques will be explained and linked to current questions.

 

The workshop is presented by:

 

 

 

 

 

 

 

This Workshop is organized in collaboration with the ACCELERATE project (Funded by the Horizon 2020 Framework Program of the European Union A.G. Number 731112).

 

The workshp is supporteed by the EASI-STRESS project (Funded by the Horizon 2020 Framework Program of the European Union A.G. Number 953219)

ACCELERATE_ND_talk_2021 - Hofmann.pdf

CERIC Large Facilities access-residual stress.pdf

GEMS-overview_MT-2021.pdf

HZG_ACCELERATE_R2B_Liehr.pdf

HZG workshop talk mef_uni-coventry.pdf

NZangenberg_ACCELERATE_09.03.2021.pdf

Staron_GEMS+RS_3.pdf

USync HZG ACCELERATE presentation.pdf

10:00 → 11:50 Session 1: Residual Stress Analysis

10:00 Welcome/Introduction

Speaker: Marc Thiry (HZG)

10:15 Motivation talk I - Bridging the gap between synchrotron/neutron stress analysis and industry

Measuring residual stresses non-destructively using deeply penetrating neutron and synchrotron x-ray probes has been employed for decades in academic work. However, despite being a unique analysis tool, the method has not yet found widespread application in industrial applications.

We will investigate the barriers for increased industrial usage of the tools – both from a technical and administrative perspective. Two identified barriers will be given extra focus: 1) usage of measurement standards, which is also the focus of a new EU project initiated in 2021, and 2) the introduction of mediator companies for measurements (see, e.g., https://www.eariv.eu/mediators).

Speaker: Dr Nikolaj Zangenberg (Danish Tecnological Institute)

10:30 Lab techniques: Hole Drilling and the Contour MethodLab Techniques: Hole drilling and contour plot

There is a range of experimental techniques available for the determination of residual stress. This talk will give an overview of the methods, their advantages and disadvantages, and particular examples of the application of incremental hole drilling and the contour method.

Speaker: Michael Fitzpatrick (University of Coventry)

10:50 Near Surface X-ray techniques

Local residual stresses are often the consequence in all technical components due to the selected manufacturing strategy. In the course of the components use, these can be superimposed locally with the load stresses and lead to premature failure. Therefore, the residual stress state influence directly the life time of technical components. To avoid this, residual stress analysis on technical components are carried out based on X-Ray diffraction methods. In some cases, construction guidelines of the industry stipulate maximum residual stress values in drawings during the planning process, which has to be checked after manufacturing the parts. The procedure for sample preparation and the measurement strategy are also partly description in test regulations and in technical standards in order to ensure comparability. In many cases, individual examinations also have to be adapted according to the respective questions. This article is intend to give an overview of the various possibilities of the targeted application of near surfaces X-ray diffraction methods to engineering issues.

Speaker: Alexander Liehr (Universität Kassel)

11:10 Bulk residual stress analysis at the synchrotron

Synchrotrons offer high photon intensities that can be used for X-ray diffraction (XRD) measurements with high spatial or time resolution. In addition, photons with high energies have a large penetration depth in many materials, enabling residual stress (RS) analysis in large samples. There are different techniques for diffraction-based RS analysis at the synchrotron using, e.g., simple transmission geometry, conical slit cells or energy-dispersive diffraction. These possibilities of synchrotron XRD complement diffraction techniques with lab X-rays at the very surface and neutrons in the bulk. The different techniques will be introduced and examples will be presented.

Speaker: Dr Peter Staron (Helmholtz-Zentrum Geesthacht)

11:30 Residual stress analysis by neutron diffraction at STRESS-SPEC

Diffraction methods are powerful tools for non-destructive analysis of applied or residual
stresses. The high penetrating power of neutrons when compared to laboratory x-ray sources,
i.e. several cm instead of a few tens of μm, opens up the possibility to analyze residual stresses
in the interior of technical components rather than just at the surface. This also allows the use
of bulky sample environment like furnaces or test rigs in order to study the evolution of stress
in components as a function of temperature and/or load. In addition the possibility to keep the
measurement gauge volume cubic in all possible sample orientations is extremely helpful in
order to analyze the local stress tensor.
In this presentation, we will give an overview on the basic principles and requirements of the
method, some advances at STRESS-SPEC and show examples of measurements on industrial
relevant materials and components.

Speaker: Dr Michael Hofmann (TU Munich)

11:50 → 12:40 Lunch Break

12:40 → 14:05 Session 2: Industrial Access to Advanced Research Infrastructures (ARI)

12:40 Motivation talk I - Mediator companies facilitating industrial use of Advanced Research Infrastructures (ARI)

Synchrotron based 3DXRD studies of rolled braze clad aluminum sheets.

Synchrotron radiation facilities have opened up possibilities to increase our knowledge of fundamental materials properties but also to better understand how materials behave in industrial processes. In this motivation talk we will briefly describe how academic expertise together with a mediator company can, by help of synchrotron based 3DXRD, give insight about industrial processes in connection with brazing of mechanically formed Al alloy components in heat exchanger assemblies.

Speaker: Dr Robert Moberg (Uppsala Synchrotronix AB)

12:55 How to access Large Scale Facilities: GEMS

GEMS is a central user access platform, where the Helmholtz-Zentrum Geesthacht provides the infrastructure for complementary research with photons and neutrons in the field of materials research. Instruments using synchrotron radiation are operated at the outstation at DESY in Hamburg and instruments using neutrons are located at the outstation at the FRM II in Garching near Munich.

Speaker: Marc Thiry (HZG)

13:05 How to acess Large Scale Facilities: CERIC ERIC

With excellent facilities in 9 countries in Central and Eastern Europe (Austria, Croatia, Czech Republic, Hungary, Italy, Poland, Romania, Serbia and Slovenia), CERIC supports proprietary research through a problem-solving approach, using some of the best scientific facilities and expertise in Central and Eastern Europe.

Speaker: Angela Zennaro (CERIC ERIC)

13:15 Discussion/Round Table with Experts

Speaker: All participants

13:45 Wrap-up, Goodbye

Speaker: Marc Thiry (HZG)