Operation Safety Analysis Of Bottom Supported Engineering Ship

Wind power is an important source of clean and renewable energy,and making full use of it can help achieve the goal of being "carbon neutral" more quickly.In this paper,for offshore wind power installation projects in intertidal zone and shallow sea areas,the following deficiencies exist in the operation of currently commonly used jack-up ships and floating crane ships :(1)jack-up ships have high economic cost,serious shortage of numbers,and are affected by water depth and geology.(2)The direct installation operation of crane ship is greatly affected by weather and ocean currents and other conditions,and the stability is poor,which leads to the uncontrollable construction period.Therefore,this paper puts forward a scheme to install offshore wind turbine by bottom-supported engineering ship.It has certain theoretical value and practical significance to carry out research on this project and determine the method to evaluate the safety performance of the operation sitting on the bottom.This paper takes a crane ship which meets the requirements of the construction area as the research object,and puts forward the scheme of engineering ships to operate On-bottom.The safety factors of bottom supported are analyzed.Based on the code,the bottom stability under extreme environmental load,the condition of 20% loss of bottom area and the most unfavorable stress condition is calculated.According to the engineering requirements of offshore wind power project,the gravity and function load of the ship are estimated,and the variable load including operation load is determined when the ship is operating at the bottom of the ship.The environmental loads,such as wind load and current load,as well as the seabed support force of the engineering ship under the normal sitting condition and the self-storage condition were calculated respectively.Among them,the wind load and the current load can be directly calculated and determined based on the empirical formula to finally determine the overall load of the engineering shipANSYS APDL was applied to establish finite element model of engineering ship,choose different draft state,the construction and storm,the bottom area of loss of various typical conditions,such as applying the boundary conditions and load,respectively calculated hull structural strength,according to the stress results and stress nephogram analysis.The calculation results show that under different water depths,the structural stress of the ship in normal operation and bottom-keeping condition changes under various operation and environmental loads.When the water depth is above 2m,the structural stress is less than the allowable stress of the corresponding material specifications,and the structural strength meets the requirements of the specifications.The stress results show that the high stress area mainly concentrates on the outer plate and bulkhead of the hull where the crane is located.The stress between the strong frame and the hull plate is larger on bottom-keeping.Under any working conditions,the stress at the junction between the transverse and vertical bulkheads and the outer plates is always large.when bottomsupported operat,the high stress area should be specially monitored.The research content of this paper can provide new solutions for offshore wind power engineering,the research method can provide reference for the study of hull strength,and the research results and some conclusions can provide reference for similar bottom-supported engineering.