Hydroelastic Dynamic Characteristics And Optimization Of Functionally Graded Material Plate Members

Functionally Graded Materials(FGM)are composite materials made of two or more materials with continuous gradient distribution in one/more directions according to the needs of practical engineering.FGM plate members are widely used in transportation,ship,ocean,machinery,and other engineering structures due to their excellent physical and mechanical properties.It is of great theoretical significance and engineering value to study the dynamic characteristics and structural optimization in the fluid.Considering the influence of internal pores,this paper first simulated two types of pores: symmetrical distribution and asymmetric distribution.The calculation model of physical parameters of FGM plates with internal pores is established with ceramic mass components as basic parameters.The potential flow theory and Bernoulli equation are used to solve the fluid dynamic pressure model at the plate surface.Based on the thin plate theory,the vibration and buckling control equations of static and axially moving FGM plate structures in the fluid are derived.Then,considering the simply supported and clamped boundary conditions,the dynamic deflection situation solution of FGM plate structures is given according to the eigenfunction of the beam.The harmonic balance method is used to solve the free vibration and forced vibration control equations of FGM rectangular plates with pores in the fluid.The effects of ceramic mass fractions,material volume fraction indexes,pores,and fluid depth on natural frequencies and dynamic responses are discussed by parameter analysis.Then,the New Mark-β numerical integration method is used to solve the maximum central dynamic deflection of the axially moving FGM plates under lateral loads and in-plane loads.The critical buckling velocity and critical load of the structures are judged by the change in the maximum dynamic deflection.The influence of axial velocities,surface internal forces,pores,and fluid on the buckling characteristics of the structure is discussed.Finally,The convergence factor and position weight in the traditional Grey Wolf Optimization(GWO)algorithm are improved,and the buckling critical load of FGM plates under different boundary conditions is optimized.The results show that the fluid can reduce the natural frequency of the FGM plate by50% and the dynamic response by 90% at most,but it has no significant effect on the critical buckling velocity and critical load of the structure.The pores reduce the effective stiffness of the plate,resulting in the decrease of natural frequencies,critical buckling velocities,and critical loads.The dimensionless fundamental frequency of the symmetrically distributed void-type plate is 1.8% higher than that of the asymmetrically distributed void-type plate.In addition,parameters such as ceramic mass fractions,material volume fraction indexes,and aspect ratios are also key factors affecting the dynamic characteristics of FGM plates in the fluid.Compared with the traditional GWO algorithm,the improved GWO algorithm has a faster convergence speed.According to the above theories,methods,and research processes,the corresponding numerical analysis programs are compiled.The calculation results are presented in the form of charts.The relevant research results enrich the research on the dynamic characteristics of FGM plate components in the fluid and have a certain significance for promoting the application of FGM plate structures in traffic engineering.