海冰弯曲破坏的数值模拟方法研究

发布时间：2019-01-12 15:21

【摘要】：在我国渤海海域，由于冬季海冰的作用，许多海上平台以及其他结构物均在潮差段安装了锥体抗冰结构。这是由于现有的许多研究成果表明冰排在锥形结构前发生的弯曲破坏所产生的冰力远小于对直立结构挤压破坏时所产生的冰力。基于此，对于海冰的弯曲破坏进程的研究已经称为冰工程界的一项重要课题。当下，对于海冰弯曲破坏的研究方法主要包括现场试验，室内模型试验以及数值模拟。而随着计算机技术的高速发展，数值模拟已经成为了这一领域的一种重要的辅助研究方法。但合理有效的数值模拟方法的研究目前还处于探索阶段。在本文即通过理论分析与数值计算的方法对海冰弯曲破坏数值模拟方法进行了有益的探索，主要开展的工作有：（1）、根据海冰的物理力学性质，对现有的海冰本构模型和破坏准则进行研究，探讨适合于海冰弯曲应力状态下的本构模型和破坏准则；（2）、在LS-DYNA中模拟圆环形冰排弯曲破坏的过程以及冰排与锥体结构相互作用的进程，提出了一种一般性的对海冰破坏准则的技术思路。 3）、通过所提出的技术思路对基于三轴压缩试验的Derradji破坏准则进行了修正，使其能够适用于海冰的弯曲破坏。通过本文的研究表明，由于海冰的弯曲破坏过程的复杂性，现有的数值模拟成果还有待进一步的深入探索。本文中所提出的对Derradji破坏准则修正后的破坏准则虽然能够在一定程度上适用于海冰的弯曲破坏，，但仍有待进一步的完善。
[Abstract]:In the Bohai Sea area of China due to the effect of winter sea ice many offshore platforms and other structures have been installed with conical anti-ice structure in the tidal range. This is because many existing research results show that the ice force caused by the bending failure of the ice row in front of the conical structure is much smaller than the ice force produced by the compression failure of the vertical structure. Therefore, the study of the bending failure process of sea ice has become an important subject in ice engineering. At present, the research methods of sea ice bending failure mainly include field test, indoor model test and numerical simulation. With the rapid development of computer technology, numerical simulation has become an important auxiliary research method in this field. But the research of reasonable and effective numerical simulation method is still in the stage of exploration. In this paper, the numerical simulation method for the bending failure of sea ice is studied by theoretical analysis and numerical calculation. The main works are as follows: (1) according to the physical and mechanical properties of sea ice, The existing constitutive models and failure criteria of sea ice are studied, and the constitutive models and failure criteria suitable for the bending stress state of sea ice are discussed. (2) the bending failure process of annular ice row and the process of interaction between ice row and pyramidal structure are simulated in LS-DYNA, and a general technical idea of sea ice failure criterion is put forward. 3) the Derradji failure criterion based on triaxial compression test is modified to make it applicable to the bending failure of sea ice. Through the research in this paper, it is shown that due to the complexity of the bending failure process of sea ice, the existing numerical simulation results need to be further explored. Although the modified Derradji failure criterion proposed in this paper can be applied to the bending failure of sea ice to some extent, it still needs further improvement.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：P731.15

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