The following parameters of the perfect elasto-plasticity model are defined for positive arguments x>0. The value of the derivative needed to define the stiffness is also specified.
Function:
For 0 < u < Dlim the relationship f = fpl(u) is defined numerically based on the inverse relationship u = u(f) defined by the following formula:
Derivative (stiffness):
Limitations:
Note that the coefficients w and a are linked by the relationship: w is a coefficient of curve filling calculated from the following formula:
and from the formula below the value for the 'a' parameter can be calculated:
