This paper explores the possibility of actively controlling the dynamic response of structures containing fluid filled porous elastic (poroelastic) materials by adjusting the properties of the fluid or solid phases of these materials. An archetypal structure is examined which consists of a rigid slab supported on a poroelastic layer. To obtain the frequency domain complex transmissibility function, the base of the structure is subjected to an impulsive loading and the response of the slab is calculated by employing the appropriate boundary conditions for the layer. A study of the effects of poroelastic material properties on the dynamic response of the structure is then presented which shows that resonant amplitude of motion is not necessarily decreased by increasing the viscosity of the fluid in the poroelastic layer. Rather, it is most effectively controlled by changing the fluid or the solid phase of the layer material so that the frequency which layer energy dissipation is maximum coincides with the structure resonant frequency. The results of this study point to ways in which poroelastic structural elements can be used to actively control the dynamic response of structures. By use of electro-rheological fluids of fluids whose viscosities are temperature dependent, for example both the structural resonant frequencies and the amplitude at resonance can be actively adjusted. Similarly, the use of solid phase materials whose porous microstructure is alterable by magnetic or electric fields could be employed for this result.
關聯:
中華民國力學學會第十四屆全國力學會議論文集(一)=Proceedings of the 14th National Conference on Theoretical and Applied Mechanics (I), pp.433-440
