细粒酒精模型冰的弯曲强度试验研究

EXPERIMENTAL STUDY ON THE FLEXURAL STRENGTH OF FINE GRAIN ETHANOL MODEL ICE

基于不同制冰条件和厚度的细粒酒精模型冰层原位悬臂梁弯曲强度试验，给出细粒酒精模型冰弯曲强度；分析了考虑和不考虑浮力效应对弯曲强度的差异；利用向上和向下弯曲强度结果给出该模型冰各向同性的证据；得到该冰弯曲强度与其密度、冰内未冻液含量和制冰过程可控制因子（冰地室内温度、升降温时间、冰厚）的关系，并作为定量控制模型冰质量的基础。

The fine grain ethanol model ice, used in the Arctic Offshore Researeh Centre (AORC),Ship Laboratory, Helsinki University of Technology, is of intemational standar for medeling intenstions between model ice and structures (ships). on of the importan laboratory simulation results is concemed with the model ice proprties. For the intoractions with inclined structures and ships, such as cone man-made islands, lighter towers, wave dams and ice-breakers, model ice flexural strength is one of the dominant fastors. A series of experimental studies have revealed the physical and mechanical properties of fine grain ethanol model ice and their relations to the known ice-making conditions (i.e. air temperature in ice basin, hme periods of decreasing and increasing air tomperabe, and model ice thickness) and yielded a new index, . t/ h2 based on the energy balance. This paper presents the experimental study theory, method and resultS on the fine grain ethanol model ice fiexural strength. The effects of buoancy, loading rates and loading directions on the model ice cantilever beam flexural strength are discussed. The authrs' findings tha flexural sbengths lowhng downwards and upwards are neary the same (the homogeneity of the fine grain model ice) are confirmed- The processes affecting the sbength with loading rates are similar to those for the natural sea ice in the Bohai Sea. The effect of buoyancy on the sbength is smaller than the error which comes from tested data- The flexural strength depends on its physical proprties, and decreases with ice density, the increasing of unfrozen solution in the ice, and the increase in the new evaluation index. From energy balance, the lereer the index is, the more the unfrozen solution in the ice is, and the higher the ice density.