冰脊压剪试验及其对直立结构冰载荷的离散元分析

DISCRETE ELEMENT ANALYSIS OF PUNCH THROUGH TEST OF ICE RIDGE AND ITS LOADS ON VERTICAL STRUCTURE

为更准确地分析冰脊与海洋结构的相互作用,本文提出一种基于粘结球体单元的冰脊离散元方法,其中龙骨与脊帆由不同尺寸的单元随机排列而成,整体呈各向同性。采用该方法模拟了一系列龙骨压剪试验,结果表明此方法能较好地表现龙骨的力学特性,且弹性模量、粘聚强度、内摩擦角等计算参数不仅影响龙骨的压剪强度,还影响其破坏模式。最后计算了冰脊与圆形直立结构的相互作用过程,其结果与ISO 19906规范结果相近,证明了该方法的可靠性。

To determine the interaction between the ice ridges and the ocean structures,a discrete element method(DEM)is used to model the ice ridge based on the bonded spherical elements in this paper.The keel and the sail of the ice ridge are constructed with various sized spherical elements via a random packing.A series of punches through tests on the keel are simulated with the proposed DEM.The reliability of the model is verified by comparing the calculated results with the measured field data.The influences of the elastic modulus,the bonding strength and the internal friction coefficient of the elements on the shear strength and the fracture mechanism of the keel are analysed.Finally,the interaction between the ice ridge and a cylindrical vertical structure is simulated with the calibrated discrete element parameters.The ice load compares well with the ISO 19906 formula.This presented DEM can be applied to determine the ice load on offshore structures.