在低温下利用单试件法确定15MnVN材料J_R阻力曲线及J_(IC)

Measuring J_(IC) and J-R Curve of 15MnVN Materal Under Low Temperature by a Single Specimen Method

试验采用三点弯曲试件,应用屈服后的卸裁柔度EBC=f(△α/ω-α_0)来确定各卸裁点下的△α_i,进而确定J_R阻力曲线。介绍了V_g-△曲线,提出第二拐点法确定启裂点的新途径,并与多试件法的结果做了比较,误差在10％以内。

The TPB specimen was used in the experiment. The Δai of every unloading points was were determined by means of the unloadingcompliance curve LEBC = f(Δa/w-a0) of a post-yeild spedimen. Meanwhie,the J-R curve was determined. A new approach to get the crack initiation point has been introduced by using the second of inflexion on the Vg-A curve. The new results were obtined from the new approach. As compared with the multispecimen methnd, this method is much betler withe erors being less than 10 per cent.