Elastic: Difference between revisions

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(New page: FLOOXS can solve for stress/strain caused by internal lattice mismatch, coefficient of thermal expansion mismatch, and the inverse piezoelectric effect. The alagator/tcl commands that des...)
 
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FLOOXS can solve for stress/strain caused by internal lattice mismatch, coefficient of thermal expansion mismatch, and the inverse piezoelectric effect.  The alagator/tcl commands that designate solving for elastic strain are given below.
FLOOXS can solve for stress/strain caused by internal lattice mismatch, coefficient of thermal expansion mismatch, and the inverse piezoelectric effect.  An example of the alagator/tcl commands that designate solving for elastic displacement are given below.


pdbSetString metal displacement Equation "elastic(displacement)"  
pdbSetString metal displacement Equation "elastic(displacement)"  
pdbSetString GaN displacement Equation "elastic(displacement)+BodyStrain(0.02e-6*(Temp-300.0))+IPZ(DevPsi)"  
pdbSetString AlGaN displacement Equation "elastic(displacement)+IPZ(DevPsi)"
pdbSetString AlGaN displacement Equation "elastic(displacement)+IPZ(DevPsi)"
pdbSetString AlGaN displacement Equation "elastic(displacement)+BodyStrain(0.002)"
pdbSetString GaN displacement Equation "elastic(displacement)+BodyStrain(0.02e-6*(Temp-300.0))+IPZ(DevPsi)"  
 
The command "elastic()" takes the solution variable displacement only as its argument and must be present in all equation commands.  The additional commands "IPZ()" and "BodyStrain()" add initial stress values to the equilibrium equation and consequently, the displacement due to inverse piezoelectric-induced stress or lattice or thermal expansion mismatch-induced stress is solved for.
A detailed description of employing stress/srtain physics into your model is described elsewhere.  Here, we focus on hoe the equilibrium equation is implemented using the finite element method in FLOOXS.
 
As designated in the class diagram on the previous page.  BodyStrain and IPZTerm are new classes derived from the ElasticTerm class.

Revision as of 14:26, 10 August 2011

FLOOXS can solve for stress/strain caused by internal lattice mismatch, coefficient of thermal expansion mismatch, and the inverse piezoelectric effect. An example of the alagator/tcl commands that designate solving for elastic displacement are given below.

pdbSetString metal displacement Equation "elastic(displacement)" 
pdbSetString AlGaN displacement Equation "elastic(displacement)+IPZ(DevPsi)"
pdbSetString AlGaN displacement Equation "elastic(displacement)+BodyStrain(0.002)"
pdbSetString GaN displacement Equation "elastic(displacement)+BodyStrain(0.02e-6*(Temp-300.0))+IPZ(DevPsi)" 

The command "elastic()" takes the solution variable displacement only as its argument and must be present in all equation commands. The additional commands "IPZ()" and "BodyStrain()" add initial stress values to the equilibrium equation and consequently, the displacement due to inverse piezoelectric-induced stress or lattice or thermal expansion mismatch-induced stress is solved for. A detailed description of employing stress/srtain physics into your model is described elsewhere. Here, we focus on hoe the equilibrium equation is implemented using the finite element method in FLOOXS.

As designated in the class diagram on the previous page. BodyStrain and IPZTerm are new classes derived from the ElasticTerm class.