GGU-ELASTIC: Signs and designations

The following sign rules are valid:

• displacement wx and wy e.g. in [m] positive in positive axis direction

• point loads Px and Py e.g. in [kN] positive in positive axis direction.

• stresses positive when tensile

• strains positive when tensile

Further designations:

• x, y = coordinates

• = Poisson's ratio [-]

• E = Young's modulus e.g. in [kN/m²]

Designation of stresses for plane strain conditions:

• sig x = stress in x - direction

• sig y = stress in y - direction

• sig z = stress in z – direction (normal to plane of observation)

• sig 1 and sig 2 = principal stresses

• tau xy = shear stress in plane of observation

Designation of stresses for axis-symmetrical strain conditions:

For axis-symmetrical strain conditions the horizontal axis is r and the vertical axis is z. The rotational axis is at r = 0.0 m (of course).

sig r = stress in r – direction (horizontal)

sig z = stress in z – direction (vertical)

sig t = stress in t – direction (normal to plane of observation)

sig 1 and sig 2 = principal stresses

tau rz = shear stress in plane of observation

The program works with true dimensions. This means that you can freely choose the dimensions for force and length. If, for example, you decide on [kN] and [m], all input must be in these dimensions (e.g. then, Young’s modulus in kN/m²).

The friction angle should always be given in sexagesimal degrees (right angle = 90°).