Optimal Design Of Fiber-wound Composite Reinforced Steel Tube Structure Based On M-PDF Algorithm

With the increasing requirements of modern transport processes,high pressure transport pipelines are being used more and more widely.Steel pipes have been used for a long time,and currently with the rise of high-pressure pipelines,the common method used in engineering is to increase the thickness of the pipe and upgrade the steel grade.But the steel pipe is heavy,poor cracking performance and corrosion resistance defects seriously restrict its development.The composite structure formed by the winding of fibre composite reinforced high-pressure steel pipe has the advantages of strong pressurebearing capacity,good cracking resistance and good corrosion resistance,which can effectively reduce the self-weight of the structure and significantly improve the pressurebearing performance,so it is important to optimise the design of its optimal performance.In this paper,the structural optimisation of the straight pipe structure and the elbow structure of the fibre-wound composite reinforced steel pipe(fibre-reinforced steel pipe)is carried out respectively,and the main research work is as follows.(1)The fiber-reinforced steel tube and steel pipe,composite tube for control simulation test,strength analysis and flexural analysis through ANSYS,comparing the characteristics and differences between steel and fiber composite in terms of load-bearing capacity.The results show that steel is more resistant to flexural damage than strength damage,and the composite material is the opposite,and the fibre-reinforced steel pipe can take advantage of the advantages of both materials to complement each other.(2)An improved hybrid particle swarm differential evolutionary frog-jumping algorithm(M-PDF)is proposed,and its global optimisation finding capability is verified using mathematical algorithms.The optimisation model is constructed for a fibrereinforced straight tube structure with the fibre angle,fibre layer thickness and steel layer thickness as design variables,and the minimum mass of the structure as the objective function under the combined internal pressure-moment loading condition with the constraints of no strength failure and flexural failure.The results show that the M-PDF optimisation results in a 47.91% reduction in the self-weight of the structure without reducing the load carrying capacity.the M-PDF algorithm has better global optimisation finding capability compared to PSO and DE,and has obvious advantages when dealing with higher dimensional problems.(3)For the fibre-reinforced steel tube elbow structure,a finite element model was established based on the fibre winding path,combined with the Kriging proxy model,to optimise the analysis and design with the objective of maximising the load carrying capacity per unit mass.The results show that the optimum laying angle of the fibres at the beginning of the circular section of the elbow should be between 50 degrees and 55 degrees.Compared to straight pipes,the elbow structure has a much lower capacity to withstand bending moments,and the structural performance can be improved by increasing the elbow bending ratio and improving the process to increase the fibre slip coefficient.