Material Data > Stress-Strain Diagram

Viewing, definition and modification of a stress-strain diagram defined by a series of value pairs relating a stress value to a strain value as abscissa. Interpolation between the defined points may be linear or parabolic. First and last points also define the absolute strain limits. The program stops the calculation if no equilibrium is found within the defined strain range; no extrapolation is performed.

Note: The value pairs must be arranged in increasing order. Stress values shall be monotonically increasing to allow for proper behavior in non-linear calculation functions. The definition of stress strain diagrams with considerable stress reduction after a peak is formally not prohibited by the program, but this may lead to malfunction (non-convergent behavior) of the respective calculation functions.

Setting	Description
Number	Ordinal number of the value pair
EPS	Strain value (per mil)
SIG	Corresponding stress value
Slope-left	Slope of the tangent at the left side of the point (ratio DeltaSIG/DeltaEPS with Delta values in internal calculation units (DeltaSIG in kN/m2 and DeltaEPS as absolute value), not in per mil and current stress unit as EPS and SIG! I.e. if working in kN/cm2 a slope of 10 kN/cm2 per 1 per mil strain will require an input value of 1.E8 (kN/m2). Note: Input will be activated after pressing the check button "Slope-left". A quadratic parabola will be created between the current and the previous point if the check button "Slope-right" of the previous point is not active, otherwise a cubic parabola will be created.
Slope-right	Slope of the tangent at the right side of the point (ratio DeltaSIG/DeltaEPS with Delta values in internal calculation units (DeltaSIG in kN/m2 and DeltaEPS as absolute value), not in per mil and current stress unit as EPS and SIG! I.e. if working kN/cm2 a slope of 10 kN/cm2 per 1 per mil strain will require an input value of 1.E8 (kN/m2). Note: Input will be activated after pressing the check button "Slope-right". A quadratic parabola will be created between the current and the next point if the check button "Slope-left" of the subsequent point is not active, otherwise a cubic parabola will be created.