| With the rapid development of the domestic economy,the application of conduit rack platforms in the construction of offshore wind farms at home and abroad will also become increasingly widespread.As domestic offshore wind power is developing into deeper water and larger,the size and weight of pile foundation guiding frames are also increasing,and the demand for steel is rising significantly.The traditional guiding frame is not versatile enough due to the change of water depth,the lower strength of the lugs and other problems lead to the guiding frame in the new water depth need to be re-made,which seriously restricts the construction cost of pile foundation.In order to break through the problem that the traditional guiding frame structure is not applicable to new water depth,this thesis,based on the previous research on truss optimisation technology,uses ANSYS and SACS joint simulation to simulate and optimise the traditional guiding frame respectively,and comprehensively evaluates the structure before and after optimisation.The relationship between the radius of the lug,the thickness of the tendon plate,the distance from the lug to the top,the spacing of the reinforcement ring and the thickness of the reinforcement ring with the stress distribution and displacement is investigated to provide a reference for improving the barrel of the guiding frame.In addition to this,the stability of the guiding frame was analysed to confirm the feasibility of the guiding frame.The main work is as follows:Firstly,the elaboration of the overall scheme design of the guide frame system for the installation of offshore wind platforms is completed.The analysis of the installation process highlights the importance of the guide frame link and the difficulties faced in making it light and necessary.In addition,the pile guide frame component system is described and the structural composition and possible problems of the steel trusses in the component architecture are highlighted,further defining the object of study and the content of the research.Secondly,a method is proposed for optimising the design of the pile foundation guide frame structure by changing the structural layout in order to improve its design,minimise weight and reduce the final cost.A three-dimensional model of a conventional guiding frame is built and the possible load conditions under each operating condition are investigated.Based on the simulation results,topology optimisation and flexural strength simulations are carried out with sufficient margin to propose a new design for the guide frame truss structure and compare the node strengths before and after to ensure that the safety factor is within the permissible range.Again,the working condition analysis and structural optimisation design of the pile guide truss is carried out.The influence of each parameter of the hanger on the hanger is investigated by numerical simulation and finite element analysis,and the possible influencing factors between them are analysed by orthogonal design experiments,and the more significant ones are selected;in order to further derive the significance of the influence between the factors,the optimal combination of the improved hanger arrangement is compared based on a combination of ANOVA with single-factor multiple comparisons and optimum level analysis.Finally,the feasibility of the optimised guide frame is verified.Based on the integration of the optimisation results,the optimum pile guide frame model is derived and its stability is verified,i.e.the overturning resistance analysis,the load bearing performance check and the slip resistance analysis.The results show that the stability of the pile guide frame is within the permissible limits of the code of practice. |
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