Application of Single-Specimen Methods on Instrumented Charpy Tests: Results of DVM Round-Robin Exercises

2008 ◽  
pp. 327-327-10 ◽  
Author(s):  
W Böhme ◽  
H-J Schindler
Keyword(s):  
Author(s):  
Sanjay Tiku ◽  
Nick Pussegoda ◽  
Morvarid Ghovanlou ◽  
W. R. Tyson ◽  
Aaron Dinovitzer

Fracture toughness of steels is conventionally measured using bend specimens and provides a conservative estimate of toughness when the actual loading is in tension. There has been widespread interest in characterizing the toughness that occurs with reduced constraint to better reflect constraint conditions typical of a relatively shallow girth weld flaw. There is currently a standardized approach to measure fracture toughness in tension loaded specimens, however, it requires testing of multiple specimens to generate a resistance curve. Recent developments in fracture toughness testing and analysis of tension loaded specimens have led to publications by CANMET and Exxon Mobil Upstream Research Company toward development of a single-specimen procedure. As part of an initiative to enhance the state of the art in strain based design and assessment methods, with the intent of providing support for the standardization of appropriate weld testing methods, BMT under a Pipeline research Council International (PRCI) project has combined the two single-specimen approaches and developed a recommended practice for fracture toughness testing using single-edge-notched tension SENT (or SE(T)) samples with fixed grip loading. The procedure has been assessed by means of a round robin test program involving laboratories from around the world. Girth welds were fabricated and base metal, heat affected zone and weld center line specimens were prepared and sent to round robin participants. For the round robin program all the participants used a double clip gauge arrangement for direct CTOD measurement and electric potential drop measurement or unloading compliance method for crack growth measurement. In this paper, the results of the round robin test program including comparison of J and CTOD resistance curves will be presented and discussed.


Author(s):  
William R. Tyson ◽  
James A. Gianetto

Assessment of the effect of girth weld flaws on pipeline integrity requires knowledge of a number of factors: pipe geometry, applied loads, flaw size, and pipe mechanical properties. Of the latter, strength and toughness are the primary factors. Toughness has conventionally been measured using specimens tested in bending to maximize constraint. While this gives a conservative estimate of toughness, it would be better to use a test that would reveal the toughness in constraint conditions typical of girth weld flaws: namely, relatively shallow flaws loaded in tension. Consequently, there is a trend to evaluate toughness using pre-cracked single-edge-cracked tension (i.e. SE(T)) specimens, and one procedure has already been standardized. However, this procedure requires the use of multiple specimens to generate a resistance curve. With the objective of devising a more economical test, a single-specimen procedure has been developed at CANMET. The viability of this procedure has been assessed by means of a round robin involving test and research laboratories from around the world. In this presentation, the results of the round robin will be presented and discussed.


Author(s):  
Diyan Pertiwi

This study is a class action that aims to improve learning outcomes in subjects PPKn sixth grade students of SDN 002 Ukui Dua. This research is motivated by the low activity and low teacher and student learning outcomes in subjects PPKn. The problem of this study is whether the implementation of a strategy to answer alternately patterned circle round robin can improve student learning outcomes in subjects PPKn in the sixth grade SDN 002 Ukui Dua? This PPKn was conducted over two cycles. Data collection techniques in this research using collection observation techniques, achievement test, and documentation. Techniques of analysis in this study is an analysis of the activities of teachers and students and learning outcomes in subjects PPKn sixth grade students SDN 02 Ukui Dua Kecamatant Ukui. The result showed that the activity of teachers has increased. At the first meeting of the first cycle of 41% was obtained with Simply Perfect category and the second meeting reached 55% with the category Fairly Perfect. In the second cycle 3 meeting to reach 75% by the Perfect category and the 4th meeting of the second cycle reaches 85% with the Perfect category. While the activity of students has increased. At the first meeting of the first cycle reaches 51% with the category Fairly Perfect and the second meeting with the percentage of 66% to the category Perfect. After the second cycle of the third meeting with a percentage of 75% with the Perfect category while in attendance for-4 with the percentage of 94% to the category of Most Perfect. Learning outcomes of students also increased from the previous students who achieve KKM only 8 votes with a percentage (45%) after the first cycle an increase in students worth over KKM which reached 14 people with a percentage of 70%. Cycle II students who achieve KKM 17 (85%).


Sign in / Sign up

Export Citation Format

Share Document