Explanation of Stress and Deformation

You can see the current Stress or Deformation within the Parameter and Single Results Window written in blue letters ("Current stress/deformation") after opening the program.

You have the opportunity to change one or more of these settings within the "Max. shear stress" window.

There you can set different stresses:

XX - normal stress which tries to compress (for s XX<0) or stretch (for s XX>0) the material in X direction

YY - normal stress which tries to compress (for s YY<0) or stretch (for s YY>0) the material in Y direction

ZZ - normal stress which tries to compress (for s ZZ<0) or stretch (for s ZZ>0) the material in Z direction

Tau XY - shear stress which tries to twist the material around a line parallel to the Z-axis

Tau XZ - shear stress which tries to twist the material around a line parallel to the Y-axis

Tau YZ - shear stress which tries to twist the material around a line parallel to the X-axis

(because there is no torque within the material, we have: Tau XY = Tau YX and so on)

You are also able to select for the displacements, giving the material shift in direction to the X, Y, and X axes:

U - shift in X direction

V - shift in Y direction

W - shift in Z direction

For each point one can always find a co-ordinate system in which all shearing components vanish. The remaining pure normal stresses S1, S2, S3 are the so called Principal Stresses. They got this name because one of them always gives the highest and another one the lowest stress at this point.

Some Stress Combinations can be chosen, too:

Von Mises Stress adds up all stresses inside a solid which contribute to shift the planes of the material against each other. Oversteps this stress combination a special value, there is talk of "plastic flow" (according to R. von Mises).

Hydrostatic Stress this is the sum of all normal stresses. With that one can examine whether the resulting stress finally either stretches or compresses the material at a given point.

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