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What is "Thickness" in a 2D model?
Posted Feb 27, 2016, 11:30 p.m. EST Microfluidics, Geometry, Structural Mechanics Version 4.3 2 Replies
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In the piezoelectric transducer (pzd) and structure mechanics (solid) physics, there is a "thickness" box in one of their trees.
I already draw the thickness of my domains in the geometry. I just want to know what is the purpose of putting a value for thickness in one of those trees since I already drawn it from the geometry. Is the thickness the same as depth? Since the disadvantage of using a 2D model is that you cannot incorporate any depth effects?
Please reply me. I really appreciate it.
Regards,
Badri
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COMSOL always assumes 3D physics, but when you decide for 2D geometry COMSOL assumes 1m per depth in the Z direction and applies coherent simplification to the physics. This implies that all loads and absolute values on a boundary (=line) in 2D are in densities per meter depth. So to get absolute values (i.e. in N for loads) you need to multiply (respectively divide) by your true depth (or height) "d" which can be defined for certain physics to make life easier for you so that absolute variables, containing the integrand over the Z depth are given in true absolute values.
Some physics have (i.e. structural) also multiple depth possible one per domain even.
To be sure you have the values you expect, always check the units, particularly in 2D and 1D physics. a *1/m or *1/m^2 could indicate a density to be multiplied by "...d" the depth manually.
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Good luck
Ivar
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