基于黏聚单元法的抗冰海洋平台与层冰相互作用数值模拟

Numerical simulation of interaction between ice-resistant platform and level ice with cohesive element method

通过商业有限元软件LS-DYNA采用黏聚单元法模拟层冰的断裂问题,在IIHR冰池模型试验相同缩尺比参数下对KULLUK抗冰平台受到的冰力进行数值计算,探究冰厚与冰速等冰况参数对平台冰力的影响。计算结果表明,在极地作业平台主要遭遇北极海域冰况范围下,相同冰厚情况时冰速变化对倒锥形结构平台的横向冰力影响不大,而同冰速时冰力随着冰厚的增加接近线性增加。同时将计算所得结果与同条件下IIHR冰池模型试验数据、ARCTEC、ACL非冻结模型冰试验数据、实船数据和通过ISO19906规范中提供的针对大锥面结构受到层冰冰力的经验公式计算所得数据等进行了对比,验证了选用冰参数的可靠性以及该数值模型在模拟大尺度宽锥形平台遭受层冰作用问题中的适用性。

As the development of the Arctic grows in intensity,the ice-resistant capability of polar operating platform is highlighted. It has been a challenge to accurately assess the ice loads that act on the structure. The cohesive element method is adopted to simulate the fracture of level ice and calculate the level ice forces of the KULLUK platform under the same scale and similar test conditions of IIHR model test through business software LS-DYNA. A parametric study conducted indicates that within the range of mainly encountered Arctic sea ice conditions,the ice velocity has little effect on the structural forces of the inverted-conical platform under the same ice thickness,while ice forces grow linearly as ice thickness grows under the same ice velocity. Based on the previous IIHR ice model test data,ARCTEC and ACL test data using non-refrigerated model ice,field test data and data calculated by empirical formula provided by ISO 19906 standard,the contrastive analysis has validated the accuracy of the selected ice parameters. The applicability to the field of simulating large-scale wide conical structure confronting level ice is also proven.