Research On The Dynamic Response Of Collision Between Jack-up Platforms And Ships

With the globalization of the economy and the intensification of resource shortages,the maritime economy has become a new hotspot for countries competing for economic competitiveness,such as offshore wind power generation,marine breeding and ranching,maritime comprehensive tourism projects and other various ways of marine economic development.As a movable platform at sea,the jack-up offshore platform has the advantages of flexible movement and wide use,and the number of constructions has increased year by year in recent years.According to the statistics of marine accidents on offshore platforms over the years,63% of the accidents are caused by ship collisions,ships and platforms are large-scale operating equipment,once a collision accident,it will inevitably cause serious economic losses and environmental pollution,and each collision affects the safety of operators.Therefore,it is of great significance to study the mechanical response law of offshore platforms to ship impacts to reduce the loss of collision accidents.During the collision between ships and offshore platforms,there are many uncertain factors,such as the speed of the collision,the angle,the impact location,and the impact of environmental loads.In this paper,numerical simulation methods will be used to study the dynamic response law of jack-up offshore platform when it is hit by ship impact and environmental load,the damage form when the ship hits different positions,the residual strength of the platform after impact,and the pile leg damage protection device,which can provide reference for the design and construction process and safety assessment of jack-up offshore platform.The significant contributions and accomplishments of this paper can be summarized as follows:Through literature research,the research methods of environmental loads and ship collisions on offshore platforms are summarized,and after comparative analysis,numerical simulation is selected as the main method of this study,and then the key technologies used in the simulation of collisions are introduced.A typical collision study experiment was selected to verify the correctness of the collision technical route.Based on the four-pile leg jack-up offshore platform designed by a company,the solid modeling of the 3D model was completed.The platform was hit by ships in different directions and speeds and the different positions of the pile legs of the platform were simulated and calculated,and the most dangerous collision direction of the platform was obtained,and the damage mode of the pile legs when hitting different positions was analyzed.According to the sea state data of the sea area where the offshore platform works,the environmental load of the platform during operation is calculated.DYNA was used to simulate and calculate the combined working conditions of the offshore platform under wind,wave and current loads in the environment and ship impacts at different speeds,different angles and different positions,and the response of environmental loads to the platform and the influence of pile leg damage were analyzed and compared,which provided a basis for the safety design of the platform.A new residual strength assessment method is proposed,and the preset damage method is used to simulate the response of the platform after being hit by the ship,and the residual strength of the platform is evaluated and calculated by the new evaluation method.The collision protection device was designed for the form of pile leg damage,and the simulation calculation was carried out to optimize the protection effect.It provides a guarantee for safety during platform operation.