CALCULATION OF THE DEFLECTION OF A PINCHED ROUND PLATE

A method for calculating the deflection of a round flat steel plate pinched along the edge, bearing an axisymmetric load, is considered. For practical calculations, dimensionless coeffi cients of deflection in the center and in the area of fixing a round flat plate pinched along the edge are applied, the stress coefficient and the accompanying function, which depends on the deflection of the plate and the pressure force on it, are taken into account

Influence of the form of axisymmetric load on the stress-strain state of an elastoplastic half-space

The problems of elastic sinking of materials and elastic restoration of an imprint under loading of an elastic-plastic half-space with an axisymmetric load of the form,P(r)=P0(1-r2/a2)β where 0<β<0.5 are considered. Expressions are obtained that describing the stress-strain state of an elastoplastic half-space. The conditions of the onset of plastic deformation in the near-surface layer and on the half-space of surface are considered depending on the parameter β.

Frequency Response of a Fractional Derivative Viscoelastic Type Lined Tunnel with Partial Sealing

Based on Biot saturated soil theory, steady state dynamic response of the system is studied in the frequency domain when the inner boundary of a fractional derivative viscoelastic type circular lined tunnel is under the axisymmetric load and fluid pressure respectively. On the basis of introducing a partial permeable boundary condition, the solutions of stress, displacement and pore pressure of the lining and saturated soil are obtained by the inner boundary of the lining and continuity conditions of the interface, besides, the stress-displacement constitutive behavior of the lining is described by fractional derivative viscoelastic constitutive model. The influence of physical parameter on the system response is investigated. It is shown that the order of fractional derivative model has a great influence on the system dynamic response, and it depends on material parameter of the lining when the inner boundary of lining is subjected to axisymmetric load. The permeability parameter of lining has significant effects on system response induced by fluid pressure.