TC1 Elastic Plastic Fracture Mechanics
Prof Uwe Zerbst
Dr. Igor Varfolomeev
ESIS Meeting at Freiburg On 5th-6th December 2012 a meeting of the TC1 (whose activity was restarted in 2010 under the Chair of U. Zerbst and I Varfolomeev) was held in Freiburg. It has been a succesfull meeting, the list of presentation as well as the presentations can be downloaded here.
Uwe Zerbst and Igor Varfolomeev
Treatment of Primary and Secondary Stresses in Fracture Assessment with and without Elastic Follow-Up (B. Ainsworth)
Experimental characterisation of fatigue resistance of pipe-to-plate welded joints under torsion loading (L. Bertini, F. Frendo)
TC1 UPDATE 2008
The Seventh International ASTM/ESIS Symposium on Fatigue and Fracture Mechanics (36th ASTM National Symposium on Fatigue and Fracture Mechanics) Sponsored by Committee E08 and ESIS was held on November 14-16, 2007 in Tampa, Florida, The conference organisers and chairmen were Rick Neu, Steve Thompson representing ASTM and Kim Wallin representing ESIS. In all, the conference was attended by 108 participants, with 26 from Europe. The papers will be published in a special STP and also as part of the ASTM JAI journal.
Subcommittee on Fracture Mechanics Testing Standard
The new version ESIS P3 of the unified test method (successor of ESIS P2) has been ready for quite a while.
TC1 UPDATE 2006
TC1 Subcommittee on Fracture Mechanics Testing Standards
In 2005 the TC1 subcommittee on Fracture Mechanics Test Standard did not meet. It’s still working on the ESIS Procedure P3 which represents an update of P2. It includes methods for testing specimens with low constraint, and these methods are being written in parallel with an ISO standard. That standard is in a voting procedure, and it may be that some national institutions suggest alterations. If this happens, then the subcommittee want to do the same changes in the ESIS method in order to avoid standards which are very similar, however, not identical.
TC1 UPDATE 2005
- Notes from the ESIS TC1 and TC8 Joint Meeting held at GKSS, Germany, 09/10 December 2003
ESIS technical committees TC1 (Elastic Plastic Fracture Mechanics) and TC8 (Numerical Methods) held a joint meeting 09/10th December at GKSS, Geesthacht, Germany. Approximately 30 engineers and scientists attended the 2 day meeting kindly hosted by Prof K-H Schwalbe. Nine technical presentations were made over the two days in addition to the plenary sessions of both committees. The themes of the meeting were; Changes in fracture toughness testing and analysis procedures; Review of numerical methods & Round-Robin studies; Advances in elastic-plastic fracture toughness methodologies. In addition to the formal presentations there were two main topics tabled for discussion in the TC1 session (i) the current status of the ESIS P2 document (Prof K-H Schwalbe) and (ii) sub/miniature sized specimen fracture toughness testing (Dr G Wardle). The main discussion topic within TC8 related to the ESIS P9-02D guideline document, and the follow up to the 3rd Phase of the micromechanical numerical Round Robin (Dr C St-Catherine).
- ESIS P2 document on fracture toughness testing procedures
The latest version of the updated ESIS P2 document had been sent out for comment early in 2003, and Prof Schwalbe along with Drs Wardle and Pisarski held a TC1.4 meeting in July to revise the document on the basis of their comments received. It was proposed that this document be given a new P3 number. This procedure, for normal quasi-static fracture mechanics testing, is now the most up to date procedure, and covers tests on: compact C(T), single edge notched bend SE(B), and low constraint mid-cracked tension M(T) test geometry's. The procedure includes the fracture toughness determination of welded joints as well as homogenous material. Fracture toughness parameters covered in this document relate to standard J-integral, CTOD, CMOD measurements but additionally includes Crack Tip Opening Angle CTOA, and crack tip displacement 5, parameters. Dissipated energy measurements are now also standardized. Prof Schwalbe stated that his intention was to have the new document ready for distribution to the ESIS committees for comment early in 2004. The document would then be peer reviewed by the committee and ratified prior to formal issue of the document.
- Test procedures for small/ miniature fracture toughness specimens
There was world-wide interest in the use of miniature specimens for obtaining realistic fracture toughness values from limited amounts of material that may be obtained from operating plant, without compromising its integrity, or from surveillance, or archive, materials. There was an activity within ISO TC164-TC4 (Dr Wardle) to look at the requirements for a new standard, or Appendix to current standards, dealing with the small specimen issue. (Within ESIS this topic is related to TC1.3 activities). However, following discussion it was concluded there was an overlap between experimental and numerical methods /damage mechanics approaches in this study area. The consensus view was that there should be a joint TC1/TC8 activity in this area. This work also meshed closely with the work of Professor Kuma on small punch testing/ damage mechanics and fracture toughness specimen behavior. It was agreed that Dr Wardle and Prof Kuma would jointly put together a plan of action. This would be distributed to ESIS committee members, and would, over the next few months, suggest a program of activities that would bring together: small specimen testing; numerical methods and damage mechanics modeling. The aim would be to link these activities to the transferability of small specimen testing to structural components.
- Follow up to the 3rd Phase of the micromechanical numerical Round Robin
Dr St-Catherine presented the Results of the ESIS TC 8 - Numerical Round Robin on Micro-Mechanical Models: Phase III for the Simulation of the Brittle to Ductile Transition Curve (see TC8).
TC1 Subcommittee on Fracture Mechanics Testing Standards
Prof. Dr.-Ing. Karl-Heinz Schwalbe
The Subcommittee is presently drafting an extended fracture mechanics test method, based on P1 and P2. This new method will contain new items such as new specimens (middle cracked tension specimens, four-point bend specimens), new test methods (crack opening displacement delta 5, crack tip opening angle psi, rate of dissipated energy), testing of thin-walled specimens, testing of weldments, evaluation of statistical bounds to fracture toughness data.
This way the most comprehensive fracture mechanics test procedure will be produced.
A second draft is just being prepared and will be discussed by the Subcommittee in due course.