TY - BOOK
T1 - On the Effectiveness of the Dynamic Force Adjustment for Reducing the Scatter of Instrumented Charpy Results
AU - Lucon, Enrico
A2 - Scibetta, Marc
N1 - RN - BLG-1059
AI - This work was performed during my secondment at NIST (National Institute of Standards and Technology) in Boulder, Colorado (USA), between June and August 2008.
The contents of this report were submitted to Journal of ASTM International for publication on 28 August 2008.
Score = 2
PY - 2008/9
Y1 - 2008/9
N2 - One of the key factors for obtaining reliable instrumented Charpy results is the calibration of the instrumented striker. An interesting alternative to the conventional static calibration recommended by the standards is the Dynamic Force Adjustment (DFA), in which forces and displacements are iteratively adjusted until equality is achieved between absorbed energies calculated under the test record (Wt) and measured by the machine encoder (KV). In this study, this procedure has been applied to the instrumented data obtained by 10 international laboratories using notched and precracked Charpy specimens, in the framework of a Coordinated Research Project (CRP8) of IAEA. DFA is extremely effective in reducing the between-laboratory scatter for both general yield and maximum forces. The effect is less significant for dynamic reference temperatures measured from precracked Charpy specimens using the Master Curve procedure, but a moderate reduction of the standard deviation is anyway observed. It is shown that striker calibration is a prominent contribution to the interlaboratory variability of instrumented impact forces, particularly in the case of maximum forces.
AB - One of the key factors for obtaining reliable instrumented Charpy results is the calibration of the instrumented striker. An interesting alternative to the conventional static calibration recommended by the standards is the Dynamic Force Adjustment (DFA), in which forces and displacements are iteratively adjusted until equality is achieved between absorbed energies calculated under the test record (Wt) and measured by the machine encoder (KV). In this study, this procedure has been applied to the instrumented data obtained by 10 international laboratories using notched and precracked Charpy specimens, in the framework of a Coordinated Research Project (CRP8) of IAEA. DFA is extremely effective in reducing the between-laboratory scatter for both general yield and maximum forces. The effect is less significant for dynamic reference temperatures measured from precracked Charpy specimens using the Master Curve procedure, but a moderate reduction of the standard deviation is anyway observed. It is shown that striker calibration is a prominent contribution to the interlaboratory variability of instrumented impact forces, particularly in the case of maximum forces.
KW - Instrumented Charpy tests
KW - striker calibration
KW - dynamic force adjustment
KW - IAEA CRP8
KW - between-laboratory scatter
KW - dynamic Master Curve
UR - http://ecm.sckcen.be/OTCS/llisapi.dll/open/ezp_90651
UR - http://knowledgecentre.sckcen.be/so2/bibref/5091
M3 - BLG - Open report
T3 - SCK•CEN Reports
BT - On the Effectiveness of the Dynamic Force Adjustment for Reducing the Scatter of Instrumented Charpy Results
PB - SCK CEN
ER -