Research On Direct Strength Assessment Of Large Performance Platform Catamaran Pontoon

This paper studies direct strength assessment method of the performance platform for large-scale live-action performance,Return to the Three Gorges.The main body of the platform is catamaran pontoon.Its scale is beyond the limitations of Construction and Classification of the Inland Waterways Steel Ships and a long-span stage steel frame is installed above the hull to meet the requirement of the performance.Cross structure is the main part of catamaran that bears the effects of lateral bending moment and torque and its structural strength must be evaluated according to the requirement of the drawing inspecting for the platform.Because of its super-standard scale and special combination structure,conventional methods in rules and hold section models FEM can’t be applied directly to analyze the global strength of the platform correctly,so it’s necessary to use the whole ship finite element method.This paper proposes a complete set of direct strength assessment method of the performance platform and put it into practice.Firstly,preliminarily analyze and evaluate the structural strength of the main parts such as the cross structure.Then,evaluate the yield and buckling strength of the whole ship structure including the stage steel frame.The results show that the structural strength of the performance platform meets the requirements of the specification.This paper summarizes the areas with high stress,which can provide reference for ship structural design.Wind load is one of the main loads of the large stage steel frame which required deep study because of its calculation uncertainty and the complex structure of the stage steel frame.Two methods are used to study the wind load of the stage steel frame.One is calculated according to Load Code for the Design of Building Structures.The other is CFD numerical simulation method.Compare the deformation and stress distribution of the large stage steel frame under wind loads calculated by two methods.The results show that both methods can reasonably simulate the actual stress of the structure.It can be calculated according to Load Code for the Design of Building Structures in consideration of safety.Study the stiffness coupling between hull structure and stage steel frame structure by comparing the results of integral calculation of the performance platform including the stage steel frame and separate calculation of the hull and the stage steel frame.It shows that the method of calculating the combined structure together is more reasonable than the method of calculating the hull and the stage steel frame separately.This research provides basis for structural design of the performance platform of Return to the Three Gorges,and also provides reference for direct strength assessment of other similar combined ships.