Transient Response of Viscoplastic and Viscoelastic Shells Submerged in Fluid Media

Abstract

The transient fluid-shell interaction problem is investigated for thin shells constructed of other than linearly elastic materials. Specifically, solutions are developed in terms of elementary functions for the transient responses of impulsively loaded, fluid-surrounded spherical shells constructed of either viscoplastic or viscoelastic materials. In all cases the fluid medium surrounding the shell is taken as inviscid and compressible and only spherically symmetric shell motions and radiation of sound into the surrounding medium are considered. It is found that the influence of material strain hardening and strain-rate sensitivity can be significant in reducing fluid-shell displacement responses. Further, limited investigations for viscoelastic materials indicate that for higher loss materials, displacement response of the shell is significantly altered by the inclusion of the viscoelastic behavior.

Dynamic Characteristics of Deeply Buried Spherical Biogas Digesters in Viscoelastic Soils

“…Thirdly, the fractional-derivative constitutive model used in this study is compared with the classical elastic model [17] and the classical viscoelastic constitutive model [18]. Substituting the classical elastic constitutive model and classical viscoelastic constitutive model used in the literature [19] into the soil equation of motion (3), respectively, changes the results of [19,20]. Figure 3 shows the changes in the curves of the radial displacement amplitude and circumference displacement amplitude as a result of the changing frequency of the three models.…”

“…Forrestal and Sagartz studied the dynamic responses of thin-walled spherical shells and cylindrical shells in homogeneous elastic soil under the action of heavy loads [2]. Duffey obtained the transient dynamic response of viscoelastic and viscous-plastic spherical die structures under impulsive loading by using a Laplace transform technique [3]. Glenn regarded the soil as a linear elastic medium and deduced the vibration response of a deeply buried spherical digester under heavy loads and pulse loads [4].…”