Cubic Stiffness Block

Cubic Stiffness blocks store a set of coefficients that determine two cubic polynomials defining a force verses deflection curve. If the Direction block selects the cubic stiffness formulation for TY direction, then the property file, for example, must contain a [CUBIC_STIFFNESS_TY] block.

The following table describes the parameters stored in a Cubic Stiffness block. Abbreviations are: [F] = force, [L] = length.

Parameter Type Dimension FX, FY, FZ Dimension TX, TY, TZ
EN real [L] Angle
ENS real [F][L-1] [F][L]/Angle
RN real [L] Angle
RNF real [F] [F][L]
OS real [F][L-1] [F][L]/Angle
OF real [F] [F][L]
O real [L] Angle
RP real [L] Angle
RPF real [F] [F][L]
EP real [L] Angle
EPS real [F][L-1] [F][L]/Angle

In a property file, a cubic stiffness block has this form:

EN  =  -0.20
ENS =  200000.0
RN  = -0.10
RNF = -30000.0
O   =  0.0
OF  =  0.0
OS  =  20000.0
RP  =  0.10
RPF =  30000.0
EP  =  0.20
EPS =  200000.0