Dynamic Behavior Analysis Of Functionally Graded Hollow Cylinders Under Thermomechanical Loads

Functionally graded materials (FGMs) are a type of multiphase materials, which aremade from a mixture of two or more materials. The composition and the properties of thematerial vary spatially and continuously, and the gradient in properties can eliminate themismatch of mechanical properties induced by the interface，so FGMs are able to bedesigned for different working conditions, and help to realize the optimum design of thestructure. At present, FGMs are applied widely in the Aerospace industry, the NuclearEnergy industry, Gas Turbine Engine industry, Civil Engineering, Precision Instrumentsindustry and Micro-Mechanism Systems.From the prospective of mechanics, the continuous and graded change of materialproperties makes the governing equation(s) variable coefficient differential equation(s),which brings about tough problems when investigating on the dynamic thermoelasticalcharacteristics of FGM structures. In this paper, based on the plain strain theory,assumed that the material properties of FGMs, except the Poisson’s ratio, are varyexponentially and continuously in the radial direction, and by means of finite differencemethod, Newmark method, iterative method and Fast Fourier Transfrom, the dynamicthermomechanical behaviors of infinite FGM hollow cylinders under axisymmetricthermal and mechanical loadings, the dynamic thermomechanical behaviors of infinitedouble-layered hollow cylinders with one FGM layer under axisymmetric thermal andmechanical loadings, the two-demensional dynamic thermomechanical behaviors ofinfinite FGM hollow cylinders under thermal and mechanical loadings, and dynamicthermomechanical behaviors of FGM hollow cylinders subjected to thermal shockloadings are researched. Numerical examples are put forword to illustrat the effect of thematerial properties, the geometry parameters, the mechanical and thermal boundaryconditions or others on the dynamic thermomechanical behaviors of FGM hollowcylinders, and many valuable conclusions are made.This thesis work will enrich and develop intelligent material structural mechanicsand thermoelasticity. It will also provides theoretical basis for safety evaluation，optimum design and on-line detection of functionally graded structures， and hasimportant theoretical and practical value.