Effect of Impact Energy on Brittle Crack Propagation Behavior of Crack Arrest Toughness Specimen - Study on Standard Test Method for Crack Arrest Toughness, K_ca -3-

摘要

In case impact energy in a brittle crack arrest toughness test isexcessively large, the impact energy gives conservative test results. Inthis research, effects of impact energy on arrest toughness, K_ca, of incrack arrest toughness specimens were investigated by dynamic elasticFEM analysis.The FEM analysis results of the record of K_d showed that the effect ofimpact was strongest immediately after impact, and graduallydecreased thereafter. The judgment of whether the impact had an effecton the results was made by calculating the ratio of the values of K_d forboth cases of considering impact and not considering impact.To verify these calculation results using a steel plate with a knownvalue of brittle crack arrest toughness under standard conditions,experiments were conducted under near limit conditions (whether theimpact had an effect on the results). The evaluation values of testspecimens were nearly located on the existing evaluation line.From the above results, in the range with no need to consider the effectof impact determined from the simplified calculation results, evaluationwas able to be conducted with little consideration of the effect ofimpact.