Cleavage modelling with experimental particle size distribution and novel particle failure criterion
Most of the existing local approaches for cleavage fracture derive from the assumptions that global failure is a weakest-link event and that only the tail of the size distribution of micro-crack initiating features is significant.This appears to be sufficient in predicting lower shelf toughness under high constraint conditions,but may fail when attempting to predict toughness in the transition region or for low constraint conditions when using the same parameters.While coupled ductile damage models with Beremin-like failure probability could be useful in the transition region,uncoupled models with a posteriori probability calculations are advantageous to the engineering community.Cleavage toughness predictions in the transition regime,which can be extended to low constraint conditions,are here made with improved criterion for particle failure and experimentally based size distribution of initiators for specific RPV steel.The model is shown to predict experimentally measured locations of cleavage initiators.Further,the model predicts the fracture toughness in a large part of the transition region and accurately predicts a measured shift with irradiation.All results are obtained without changes in model parameters.This suggests that the model can be used for assessing toughness changes due to constraint- and temperature-driven plasticity changes.
RPV steel local failure criterion global failure probability transition temperature regime
Andrey P Jivkov Peter James
School of Mechanical,Aerospace and Civil Engineering,The University of Manchester,Manchester M13 9PL AMEC,Walton House,Birchwood,Warrington WA3 6GN,UK
国际会议
北京
英文
1-10
2013-06-16（万方平台首次上网日期，不代表论文的发表时间）