PARAM, KDAMP

Bulk Data Entry Enters viscous modal damping into the stiffness matrix as structural damping.

Parameter Values Description
KDAMP <-1, 1 >
-1
Modal damping is entered into the complex stiffness matrix as material damping.
1 (Default)
Modal damping is entered into the viscous damping matrix.

Comments

  1. To achieve identical displacements in Modal frequency response or Modal transient analyses when the SDAMPING Subcase Information Entry is used instead of PARAM, G, the steps described here can be followed:
    • The TYPE field in the TABDMP1 or TABDMP2 Bulk Data Entry should be set to CRIT. This TABDMP1 or TABDMP2 Bulk Data Entry is referenced by the SDAMPING Subcase Information Entry.
    • Set the damping value (field gi MathType@MTEF@5@5@+=feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLnhiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=xfr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaam4zamaaBaaaleaacaWGPbaabeaaaaa@37FC@ ) in the TABDMP1 or TABDMP2 Bulk Data Entry equal to half of the value of PARAM, G (that is set the constant value to C/C0 MathType@MTEF@5@5@+=feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLnhiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=xfr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaam4qaiaac+cacaWGdbWaaSbaaSqaaiaaicdaaeqaaaaa@391F@ ).
    • Set PARAM,KDAMP,-1 (See description above).