【摘要】 试验测得海冰平面应变断裂韧度(K_IC)范围为11—77 kN/m^3/2,平均值为32kN/m^3/2。由试验结果得知海冰的断裂韧度与加载速度、冰晶颗粒、试验温度有密切的关系。这些因素对应力强度因子K_IC临界值有较大影响。结果表明,当加载速度增大时,K_IC值减小;当温度升高时,K_IC值减小。更多还原

【Abstract】 In this paper, a test item in small scale is discussed. The major content of test is the fracture toughness of sea ice at outdoors.American E399-81 standard test method adopted to test the 3-point curved beam test for 3 kinds of ice samples totalling 130 were made at 5 different temperatures and 6 loading speeds. The range of plane strain fracture toughness of sea ice KIC of 11-77 kN/m3/2, averaging 32 kN/m3/2 was obtained which agrees with that obtained by others. The value is less than that of the fresh water ice KIC..Obtained also from the test is a close relation between fracture toughness of sea ice and the loading speed during testing, the test temperature of sea ice and ice crystalline particles. These factors rather greatly affect the critical value of stress strength factor KIC. To certain limit, the KIC value indicates that, when the loading speed increases, the fracture toughness KIC decreases and when the speed becomes slow, the KIC value becomes great. To certain temperature limit, the lower of sea ice temperature, the greater the fracture toughness of sea ice. This relation is similar to the relation between sea ice compressive strength and temperature. The problem regarding the size effect of sea ice fracture sample and the relation betwen KIC and the size of ice crystalline particles is also discussed. In general, if the particle is rather great, the fracture toughness presented is also rather great. As the sea ice is of anisotropic structure, the test sample used for this test is that whose direction of vertical sea level is in parrallel with the direction of the growing up of ice crystal.更多还原