Altair OptiStruct

2020.1

Altair OptiStruct

2020.1

DOPTPRM, PNORM

Bulk Data Entry Specifies the value of the power (or penalty) $p$ , used in the Stress NORM Method for stress response calculation in Lattice Structure Optimization.

Definitions

Parameter	Values	Description
`PNORM`	Real ≥ 1.0 Default = 6.0	The Stress NORM Method is used to approximately calculate the maximum value of the stresses of all the elements included in a particular response. This is also scaled with the stress bounds specified for each element. Therefore, to minimize the maximum stresses in a particular element set, the resulting stress `NORM` value ( $σ_{NORM}$ ) is internally constrained to a value lower than 1.0.

Comments

The stress response will move towards the stress average as PNORM is decreased. It is recommended to use the default value of 6.0, unless its alteration is necessary.
PNORM values greater than 6.0 converge closer towards the maximum, however, the calculation can possibly become numerically unstable.