scholarly journals A Multiscale Model Based On Intragranular Microstructure: Influence Of Grain-Scale Substructure On Macroscopic Behaviour Of An IF-Steel During Complex Load Paths

2007 ◽  
Author(s):  
Gérald Franz ◽  
Farid Abed-Meraim ◽  
Tarak Ben Zineb ◽  
Xavier Lemoine ◽  
Marcel Berveiller
Keyword(s):  
Multiscale Model ◽  
If Steel ◽  
Complex Load ◽  
Model Based ◽  
Load Paths

Push-Over Response of a Jack-Up on Sand of Different Relative Densities

2009 ◽  
Author(s):  
Britta Bienen ◽  
Mark J. Cassidy ◽  
Christophe Gaudin
Keyword(s):  
Wind Waves ◽  
Scaled Model ◽  
Environmental Loading ◽  
Complex Load ◽  
Geotechnical Centrifuge ◽  
Overall Response ◽  
Load Paths ◽  
Numerical Predictions ◽  
Macro Element ◽  
Jack Up

On location offshore, jack-up structures are subject to environmental loading from wind, waves and current in addition to self-weight. Over the operational period of the jack-up, the environmental loading on a given site may not be unidirectional along the jack-up’s ‘axis of symmetry’ but may act from different directions and/or be non-collinear (i.e. wind acting from a different direction than waves and current), resulting in complex load paths at the spudcan footings. This paper discusses load paths obtained from experiments on a scaled model jack-up for two different horizontal loading directions and illustrate the implications of spudcan load paths for the overall response of a jack-up to failure. Similar tests were performed at two different relative sand densities, allowing the influence of relative density on jack-up behavior to be investigated. Similitude to the prototype was achieved by conducting the experiments in a geotechnical centrifuge at 200g. The paper concludes with numerical predictions of the experimentally measured response, using a macro-element to model the soil-spudcan interaction coupled to a structural finite element program. The footing macro-element has been developed based on plasticity theory and single footing experiments, but its ability to predict the respective load paths of each of the spudcans in a multi-footing system is demonstrated here. The paper further provides the experimentally measured jack-up push-over capacity and numerical predictions in the context of recommendations of current guidelines. This highlights the requirement of nonlinear elasto-plastic modelling of the load-displacement behavior of the jack-up foundations in order to predict the overall response of the system.

Predicting the Magneto-Mechanical Behavior of MSMAs Subject to Complex Load Paths

2012 ◽  
Author(s):  
Heidi P. Feigenbaum ◽  
Constantin Ciocanel ◽  
Alex Waldauer
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Mechanical Behavior ◽  
Shape Memory ◽  
Compressive Stress ◽  
Complex Loading ◽  
Model Parameters ◽  
Variable Load ◽  
Complex Load ◽  
Load Paths

The microstructure of magnetic shape memory alloys (MSMAs) is comprised of tetragonal martensite variants, each with their preferred internal magnetization orientation. In the presence of an external magnetic field, the martensite variants tend to reorient so that the preferred internal magnetization aligns with the external magnetic field. As a result, MSMAs exhibit the shape memory effect when there is a magnetic field in the vicinity of a material point. Furthermore, the tetragonal nature of the martensite variants allows for a compressive stress to cause variant reorientation. This paper studies the magneto-mechanical behavior of MSMAs under various load paths, including complex loading conditions where both the applied magnetic field and compressive stress vary simultaneously. Typically, MSMAs have been studied experimentally and modeled mathematically with either axial compressive stress or transverse magnetic field varying and the other remaining constant. For each load case, the mathematical models are calibrated with a set of experimental data that mimics those to be predicted. Model parameters have been found to be quite different when the calibration was performed with experimental results from different load cases. This work investigates if current models, namely the Kiefer and Lagoudasmodel or the Waldauer et al. model, are capable of predicting both of the typical loading configurations mentioned above with a single calibration. Furthermore, this work uses the Waldauer et al. model to simulate more complex loading, where an MSMA element is subject to simultaneously varying stress and field; this type of loading might occur if an actuator is being designed to displace a variable load over a controlled distance.

scholarly journals Dimensional Reduction of a Multiscale Model Based on Long Time Asymptotics

2017 ◽  
Vol 15 (3) ◽  
pp. 1198-1241
Author(s):  
Frédérique Clément ◽  
Frédéric Coquel ◽  
Marie Postel ◽  
Kim Long Tran
Keyword(s):  
Dimensional Reduction ◽  
Multiscale Model ◽  
Model Based ◽  
Time Asymptotics ◽  
Long Time ◽  
Long Time Asymptotics

Sand-to-Concrete Interface Response to Complex Load Paths in a Large Displacement Shear Box

2008 ◽  
Vol 31 (4) ◽  
pp. 100220 ◽  
Author(s):  
L. D. Suits ◽  
T. C. Sheahan ◽  
Jesús E. Gómez ◽  
George M. Filz ◽  
Robert M. Ebeling ◽  
...  
Keyword(s):  
Large Displacement ◽  
Complex Load ◽  
Load Paths ◽  
Shear Box ◽  
Concrete Interface
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