Significance of strain-hardening and strain-rate effects on the transient response of elastic-plastic spherical shells

1970 ◽  
Vol 12 (9) ◽  
pp. 811-825
Author(s):  
Thomas Duffey
Keyword(s):  
Strain Rate ◽  
Strain Hardening ◽  
Transient Response ◽  
Spherical Shells ◽  
Strain Rate Effects ◽  
Elastic Plastic ◽  
Rate Effects

Viscous–elastic–plastic modelling of one-dimensional time-dependent behaviour of clays

1989 ◽  
Vol 26 (2) ◽  
pp. 199-209 ◽  
Author(s):  
J.-H. Yin ◽  
J. Graham
Keyword(s):  
Strain Rate ◽  
Constitutive Models ◽  
Constitutive Modelling ◽  
Time Dependent ◽  
Creep Tests ◽  
Strain Rate Effects ◽  
One Dimensional ◽  
Elastic Plastic ◽  
Constant Rate ◽  
Rate Effects

Increased attention has recently been directed towards the influence of time and strain-rate effects on the behaviour of clays in one-dimensional (1-D) laboratory consolidation. The improved understanding coming from these studies must now be incorporated into improved constitutive models that can be used for analysis of foundation settlements. This paper presents a 1-D model for stepped loading using a new concept for establishing "equivalent times" during time-dependent straining. This model is then developed into a general constitutive equation for continuous loading. The model uses three parameters, λ, κ, and ψ, that can be easily found using conventional oedometer tests.The general model has been used to develop analytical solutions for creep tests, relaxation tests, constant rate of strain (CRSN) tests, and tests with constant rate of stress (CRSS). Results from three different clays have been used to examine the validity of the model. Key words: consolidation, constitutive modelling, elastic-plastic, viscous, time, creep, strain rate, relaxation.

Strain-Rate Effects in the Dynamic Buckling of a Simple Elastic-Plastic Model

1997 ◽  
Vol 64 (1) ◽  
pp. 193-200 ◽  
Author(s):  
D. Karagiozova ◽  
N. Jones
Keyword(s):  
Strain Rate ◽  
Plastic Material ◽  
Rate Sensitivity ◽  
Dynamic Buckling ◽  
Strain Rate Effects ◽  
Plastic Model ◽  
Elastic Plastic ◽  
Rate Effects ◽  
Elastic Plastic Material ◽  
The Impact

The phenomenon of dynamic buckling is examined when the influence of material strain-rate sensitivity is retained in the basic equations for a simple elastic-plastic model with linear strain hardening when subjected to an impact by a mass. Two approaches are proposed for taking into account the material strain-rate effects and both use the Cowper-Symonds constitutive equation. The critical impact velocities depend on the impact mass and are determined for a wholly elastic material, a strain-rate insensitive elastic-plastic material and an elastic-plastic material with a dynamic yield force together with linear or nonlinear hardening due to the strain-rate effects. The results obtained show that both strain-rate sensitive models predict impact velocities which are higher than those predicted by the strain-rate insensitive idealization and that the influence of any initial imperfections is important for the three material models considered.

Sign in / Sign up

Export Citation Format

Share Document