In this thesis, a physical model test is designed to calculate the fluid damping coefficient of Hall anchor and analyze the variation trend of anchorage velocity in water. Combined with the numerical simulation results from finite element software ANSYS/LS-DYNA, the influence of anchorage load on the damage degree of submarine pipeline under different factors is determined. The research results of this thesis can provide theoretical reference for the buried depth and protection of submarine pipelines.
In case of emergency when the ship encounters some force that is difficult to be resisted during navigation or mooring, the ship may temporarily anchor in the designated pipeline protection zone, affecting the safe operation of the pipeline. In order to protect the pipeline from the impact of ship accident and avoid the influence of drag force to cause deformation and breakage of the pipe, before construction, the way to make sure that pipeline is not anchored by the impact on the basis of the third party damage is very important because it can save the cost for the layout of pipeline. Therefore, the optimal embedding depth of the pipe should be evaluated in a scientific and reasonable method and into a meaningful research content.
As early as 1993, Al-Warthan and Chung(1993) applied discrete element method to the analysis of the factors of pipeline damage under three different loads. The establishment of physical model simulation in this thesis also contains the use of the previous analysis of pipeline impact substrate by Gan and Yan(2012) for reference. In this thesis, a physical model test is designed to analyze the variation trend of the anchorage velocity in water. With data obtained from finite element software, the damage degree of the submarine pipeline affected by anchorage load is determined under the influence of different factors. The method utilized in this process is numerical simulation. Previously, Bai(2013) and Yu(2016) respectively conducted researched the mechanical damage of pipes under load impact and Yu Jianxing(2016) also obtained the normal distribution of energy transfer induced by transverse impact of pipes. Zeinoddini(2013) carried out extensive experiments on the dynamics and quasi-static behaviors of steel pipe candidate materials under transverse stress. In this thesis, three-dimensional simulation is also carried out to analyze the damage caused by the anchor to the pipeline. Based on previous researches, the buried depth of the pipeline corresponding to different degrees of damage is obtained. It is of great significance for guidance for engineering regarding the buried depth of the pipeline. The research results can provide theoretical references for the protection of the submarine pipeline, too.
