The prediction of fatigue lifetimes in a model structure using a non-linear kinematic hardening model with continuum damage

1989 ◽  
Vol 31 (7) ◽  
pp. 537-548 ◽  
Author(s):  
D.A. Lavender ◽  
D.R. Hayhurst
Keyword(s):  
Kinematic Hardening ◽  
Model Structure ◽  
Continuum Damage ◽  
Hardening Model ◽  
Non Linear

Enhanced Kinematic Hardening Model for Load-Dependent Stiffness and Damping of Jack-Up Foundations

2018 ◽  
Author(s):  
Maas Hoogeveen ◽  
Hugo Hofstede ◽  
Amir M. Kaynia
Keyword(s):  
Time Domain ◽  
Kinematic Hardening ◽  
Fe Model ◽  
Time Domain Simulation ◽  
Backbone Curve ◽  
Response Curves ◽  
Hardening Model ◽  
Non Linear ◽  
Stiffness And Damping ◽  
Jack Up

Dynamic analysis of jack-up platforms is generally carried out using approximated linear foundation springs and equivalent viscous damping. Advanced geotechnical analysis of foundations of jack-up platforms results in load-dependent stiffness and damping. Such analyses are often based on the finite element method as used for detailed site specific analyses with proper nonlinear soil models to generate nonlinear response curves, the so-called backbone curve, for the relevant loading conditions. The same FE model can be used to compute the strain energy in the soil elements and assign the corresponding energy losses in the elements based on lab tests or literature data, and integrate over the domain to compute the foundation hysteretic damping as function of loading. The state of the art method of using the backbone curve together with a kinematic hardening model to account for the hysteretic foundation response does not provide a good match between the simulated and computed damping. The hysteresis model proposed in this paper is a kinematic hardening model enhanced with a non-linear spring. It is an engineering solution to implement both a given load-dependent stiffness and load-dependent damping of a complex element subject to an irregular loading signal for purposes of time domain simulation. This model combines a kinematic hardening model which provides the required hysteresis with a non-linear elastic spring which provides the required stiffness. This model is suitable for time domain simulation of irregular loads and yields a propeller-like shape in the load-displacement plane. This paper introduces the problem of load-dependent stiffness and damping through a case study considering time domain simulation of the dynamic behavior of a jack-up platform. The paper presents a validation of the proposed model and a comparison between the common practice model and the enhanced kinematic hardening model.

scholarly journals Spring-back Prediction of MS1470 Steel Sheets Based on a Non-linear Kinematic Hardening Model

2013 ◽  
Vol 22 (6) ◽  
pp. 303-309 ◽  
Author(s):  
S.C. Park ◽  
T. Park ◽  
Y. Koh ◽  
D.Y. Seok ◽  
T. Kuwabara ◽  
...  
Keyword(s):  
Kinematic Hardening ◽  
Spring Back ◽  
Hardening Model ◽  
Steel Sheets ◽  
Non Linear

Surface plastic strain in contact problems: Prediction by a simplified non-linear kinematic hardening model

2009 ◽  
Vol 44 (3) ◽  
pp. 187-199 ◽  
Author(s):  
A Mazzù
Keyword(s):  
Plastic Strain ◽  
Contact Surface ◽  
Kinematic Hardening ◽  
Contact Problems ◽  
Rolling Contact ◽  
Isotropic Hardening ◽  
Surface Plastic ◽  
Direction Parallel ◽  
Hardening Model ◽  
Non Linear

A previously published model for plasticity assessment in rolling contact, based on a simplification of the non- linear kinematic and isotropic hardening model of Chaboche and Lemaitre, is discussed, and an update is introduced in order to improve its accuracy in the plastic strain prediction within the region just underneath the contact surface. The update is based on a correction of the yield limit and of the strain rate as a function of the load ratio of the tensile stress in the direction parallel to the contact surface. The effectiveness and the accuracy of the updated model in not too severe conditions are demonstrated through comparisons with results obtained by finite element model (FEM) analyses. An application of the model to some experimental results obtained on rail and railway wheel steels is also carried out, and quite good agreement is found in plastic strain prediction, although some discrepancies are found. The method appears to be a valid tool for practical application, especially for its ability of combining the effects of different phenomena and of simulating a number of cycles of the order of millions in a reasonable time.

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