The Structural Strength Analysis Of Catamaran Bottom Supported Wind Turbine Installation Platform

The coastal intertidal zone all of a submerged when the tide comes in，after the ebb outof the water.These regions mainly used for mariculture and navigation，and utilization oflow value.But wind energy resource is rich in coastal intertidal zone and the land is flat，these area have the conditions to develop the coastal wind power resource.But the depth isshallow and the bearing capacity of the foundation soil is weak，normal jack-up installationvessel/platform are unable to enter this area，the terrain conditions and the hydrologiccharacteristics of this area which brings great difficulty to the engineering project.Thededicated wind turbine installation engineering vessel/platform are necessary to implementthe development of wind power generation in intertidal area，so it has the theoretical andpractical significance to research on the intertidal wind turbine installation vessel/platform.The paper focus on the study of a new type intertidal catamaran bottom supportedwind turbine installation platform.The basic scheme of the platform was put forward，andthe main structure of was designed base on the rules.On bottom stability of was calculatedwhile the platform in adverse stress state under the extreme environmental loads.According to the work requirements and arrangement，the gravity and functional loadswas estimated，to determine the empty platform weight and the variable loads.Theenvironmental loads and seabed supportiveness were calculated on the basis of rule undernormal working condition and the storm condition，wind load and current load weredetermined directly base on rules.In accordance with the Stokes wave and the Linear waveby design wave method，to determine the wave load.MSC.Patran/Nastran software was applied to build the finite element model of theplatform structure.Full static load condition，submerged floating，operating and the stormcondition were selected，the yield strength of the platform structure were analyzed by thefinite element method.The FEM result illuminates that the platform stress were less thanthe corresponding allowable stress of materials under the normal working condition and thestorm condition，the strength of the platform structure meet the requirements of thespecifications concerned.Stress results show that，high stress area are mainly concentrated in plate and bulkheadof the upper platform under normal operating condition；the column plate of the junctionunder the extreme condition；the junction of longitudinal and transverse bulkhead of engineroom and generator room under any condition，These region should be taken into specialconsideration.Combined with area loss situation while the crane above the area，the resultsshow that the platform is dangerous when the area loss below the column；and the platformis still safe when the area loss beyond the column boundary region.The research results and some conclusions of this article could provide reference forthe structure design of the platform，and the research method provides guidance for thesimilar platform development and study.