Measurements of fracture toughness applying a four-point-bending technique of ice core B34 from Kohnen Station, Dronning Maud Land, Antarctica@en

The critical fracture toughness is a material parameter describing the resistance of a cracked body to further crack extension. It is an important parameter to simulate and predict the break-up behaviour of ice shelves from calving of single icebergs to the disintegration of entire ice shelves over a wide range of length scales. The fracture toughness values are calculated with equations that are derived from an elastic stress analysis. Additionally, an X-ray computer tomography (CT scanner) was used to identify the density as a function of depth. The critical fracture toughness of 91 Antarctic inland ice samples with densities between 840 to 870 kg/m**3 has been determined by applying a four-point-bending technique on single edge v-notched beam samples. The examined ice core was drilled 70m north of Kohnen Station, Dronnning Maud Land (75°00' S, 00°04' E, 2882 m).临界断裂韧性（critical fracture toughness）是表征含裂纹体抵御裂纹进一步扩展能力的材料参数。其是模拟与预测冰架崩解行为的重要参数，适用尺度范围覆盖从单个冰山脱离到整片冰架解体的全尺度区间。该断裂韧性数值通过弹性应力分析推导得到的计算公式进行计算。此外，研究采用X射线计算机断层扫描（X-ray computer tomography，CT扫描仪）技术，测定了冰样密度随深度的变化规律。本次研究针对91块密度介于840 kg/m³至870 kg/m³之间的南极内陆冰样，通过对单边V形切口梁试样开展四点弯曲试验，测定了其临界断裂韧性。所检测的冰芯钻取自毛德皇后地（Dronning Maud Land）科恩站以北70米处，具体坐标为南纬75°00′、东经00°04′，海拔2882米。