Research On Load Characteristics Of Column Under Focusing Wave

In recent years,the development and utilization of deep-sea oil and gas mineral resources have received increasing attention from various countries.However,the marine environment continues to deteriorate,and extreme sea conditions such as wave slamming and ringing(high-frequency resonance response)continue to appear,posing a major threat to the safety of marine structures and marine workers.China is striving to realize the great transformation from a maritime power to a maritime power.The marine oil and gas development areas have gradually moved from shallow seas such as the Bohai Sea to the South China Sea."Made in China 2025" has a clear plan,including marine engineering equipment and high-tech vessels as one of the important development areas,and a large number of deep-water development equipment are ready to go.A deep understanding of the effects of extreme waves on marine structures is essential to improving the design standards for ships and offshore platforms,ensuring the safety of marine equipment and marine personnel,and has important practical engineering significance for China's development.This article selects focusing wave to simulate extreme ocean waves.Focused waves are a large transient wave.A square pillar is used as the research object.Combined with numerical calculations and model tests,the wave force characteristics under the action of focused waves are comprehensively studied.The three fixed forms are fixed,single-degree-offreedom heave,and single-degree-of-freedom surge.For three different pillar-fixing forms,the effects of different wave parameters on the wave forces on the columns are analyzed,and perform high-order separation of the wave force on the columns;finally,the influence of motion on the wave force on the column is comprehensively analyzed.This research carried out physical experiments in wave tanks on the one hand,and based on computational fluid dynamics,established numerical wave tanks that were consistent with the physical tests for numerical calculations.Firstly,the generation method,numerical calculation method and physical experiment setup of the focused wave are introduced in detail.Later,the results of monitoring the wave force on the column,the change of the flow field around the column,and the column movement in the physical experiments and numerical calculations are introduced.Finally,the relationship between the peak wave force and the wave scattering parameters and wave steepness of the column under various fixed conditions are analyzed.The phase-inversion method is used to analyze the higher order wave force on the column.This paper systematically studies the load characteristics of fixed and single-degree-of-freedom moving columns under the action of focused waves.The effects of scattering parameters and wave steepness on the wave forces on columns and the higher-order characteristics of wave forces on columns are studied.The results of physical experiments and numerical calculations are compared and analyzed,and a list of meaningful conclusions is obtained.The study found that the single-degree-of-freedom surge alleviated the wave force in the x-direction and the z-direction.The single-degree-of-freedom heave has a small effect on the wave forces of each order in the x-direction,and aggravates the wave force of each order in the z-direction.The higher-order components are more prominent,which further increases the z-direction wave force.