Vibration Characteristics And Structural Optimization Of Underwater Pile Gripper

Jacket platform is an important facility for exploiting offshore oil resources at present,and the underwater pile clamp plays an important role in its construction.A platform has four pile legs,each with three skirt sleeves.After piling,the underwater pile clamp installed on the skirt sleeve is responsible for holding the pipe pile until the grouting is completed,during which time the equipment acts as a temporary connection between the jacket and the pipe pile.At present some domestic apparatus underwater clip pile has been put into use,but there is still a gap with foreign products on work performance,this topic is based on"underwater clip pile industrialization",to analyze its vibration characteristics,the optimization design is made to the jaw,the purpose is to improve performance of domestic underwater clip pile,promote the rapid development of related industries.In this paper,based on the mechanical analysis of the claws of underwater pile clamps,the mechanical models of pressor teeth and pipe piles are established by combining dimensionality reduction method and contact mechanics,and the embedment depth of pressor teeth is calculated,and the distribution of stress and deformation is obtained.The finite element model of the gripper and the pipe pile was built by the Transient Structural module of Ansys.The clamping process was simulated by applying driving load,and the deformation and stress cloud map of the gripper was obtained.On the basis of theoretical analysis and simulation analysis to complete the check.According to the actual situation of the underwater pile clamp in the sea area,the wave force on the pile leg,the sheath,the connecting plate and the frame ring is calculated by using the linear wave theory and Morrison equation.According to the installation situation of the underwater pile clamp,the analysis idea of "outside-in" is proposed.Firstly,the dynamic response of the pile leg and connecting plate under wave force is studied through harmonic response analysis,and then the dynamic response of skirt sleeve and frame ring is studied through transient dynamic analysis.The wave equation of pipe pile under impact load was established according to elastic dynamics theory,and the simulation analysis was completed by explicit dynamics module,and the deformation and stress cloud diagram of the claw was obtained.On the basis of statics and dynamics analysis,optimization design is carried out from three aspects of structure type,material property and dimension parameter.The theoretical analysis of four kinds of gripper was completed by contact mechanics and elasticity mechanics,and then the simulation analysis was completed by Transient Structural module.After that,the gripper was screened according to the strength standard.Taking the material properties,positioning size and shape size of the clamping tooth as design variables,and the maximum deformation value and the maximum equivalent stress value of the clamping tooth in the process of embedding the pipe pile as target variables,interpolation optimization was completed by Response Surface module of Ansys,and the Response Surface relationship between the design variable and the target variable was obtained.The experimental platform was set up.Firstly,the pressure holding experiment of underwater pile clamp was carried out to check the sealing performance of its hydraulic cylinder and analyze the influence of different ambient temperature on its working pressure.After that,a variety of gripper clamping experiments were successively completed to verify the correctness of structure optimization,the effectiveness of parameter optimization and the feasibility of material substitution.