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

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）是表征含裂纹体抵抗裂纹进一步扩展能力的材料参数。该参数是模拟与预测冰架崩解行为的关键物性指标，可覆盖从单座冰山崩解至整个冰架解体的全尺度范围。断裂韧性值通过基于弹性应力分析推导得到的方程进行计算。此外，本研究采用X射线计算机断层扫描（X-ray computer tomography, CT扫描仪）技术，测定了冰密度随深度的变化关系。本研究通过对单边V形切口梁试样开展四点弯曲试验，测定了91块密度介于840~870 kg/m³的南极内陆冰样品的临界断裂韧性。本次测试所用冰芯采自德龙宁·毛德皇后地（Dronnning Maud Land）科恩站以北70米处，其地理坐标为南纬75°00′、东经00°04′，海拔2882米。