بایگانی برچسب برای: Creep

Nonlinear Viscoelastic Analysis of Thick Walled Cylindrical[taliem.ir]

Nonlinear Viscoelastic Analysis of Thick Walled Cylindrical Composite Pipes

This paper analyzes the effect of the polymer matrix non-viscoelastic behaviour in the mechanical behaviour of thick multilayered cylinders. The original contribution of this work is to provide novel approximate analytical solutions to compute the timedependent internal stress state throughout the pipe thickness within the framework of nonlinear viscoelasticity theory. The structures considered are thick, multilayered anisotropic infinitive long cylinders subjected to axisymmetric mechanical loading .Under such conditions there is an exact elastic solution which naturally satisfies equilibrium, strain-displacement, compatibility and boundary conditions for the stated constitutive equations and loading. Due to the continuous stress variations throughout the cylinder thickness, the proposed nonlinear viscoelastic solution assumes the averaged stress state to calculate the nonlinear elastic and viscoelastic factors in each layer. Furthermore the solution is obtained assuming that the creep strains, within each layer, are constant through the thickness. The proposed algorithm converges to the exact solution when the number of layers is artificially increased. For the linear viscoelastic case the proposed solution proved to match the exact known solution for isotropic viscoelastic materials. Finally several invented cases are run to illustrate the importance of the viscoelasticity phenomenon on the internal stress field throughout thick laminated cylinders.
Investigation of the cracking of CFRD face plates[taliem.ir]

Download Investigation of the cracking of CFRD face platesِ

The primary goal of this study was to examine the cracking behavior of the face plate of a CFRD over its life cycle. Analyses of the construction stage, impounding, long-term deformation and earthquake loading were conducted in sequential phases using a 2-D plane-strain model with the appropriate nonlinear constitutive relationships for the dam constituents. The state of stress and the cracking behavior of the plate were found to be substantially different in the short and long term. Earthquake loading appears to be a critical load condition for the face plate; cracking increased significantly after ground shaking
Investigation of the cracking of CFRD face plates[taliem.ir]

Investigation of the cracking of CFRD face plates

The primary goal of this study was to examine the cracking behavior of the face plate of a CFRD over its life cycle. Analyses of the construction stage, impounding, long-term deformation and earthquake loading were conducted in sequential phases using a 2-D plane-strain model with the appropriate nonlinear constitutive relationships for the dam constituents. The state of stress and the cracking behavior of the plate were found to be substantially different in the short and long term. Earthquake loading appears to be a critical load condition for the face plate; cracking increased significantly after ground shaking