RESVEC

Subcase Information Entry

RESVEC – Controls Residual Vector Calculation

Description

The RESVEC command can be used in the Subcase Information section to control the calculation of residual vectors.

Format

RESVEC(type, damping, VISC_INC=visc_inc, VISC_EXC=visc_exc) = option

Argument	Options	Description
type	<UNITLOD, APPLOD> Default = UNITLOD	UNITLOD:	Generates residual vectors based on unit loads at the dynamic loading's degrees-of-freedom. A unit load residual vector is created for every loaded DOF from all SUBCASEs. For normal modes and modal complex eigenvalue analysis, a residual vector is created for each USET and USET1 U6 DOF.
		APPLOD:	Generates residual vectors based on the dynamic loading of the modal frequency response analysis at zero Hz and transient analysis at time = zero. For frequency response analysis, one or two residual vectors are generated for each SUBCASE based on whether the real and imaginary loads are different at zero Hz. A single residual vector is created for each transient SUBCASE. The values at each loaded DOF correspond to the load on that DOF at zero Hz or time = zero. APPLOD is not valid for normal modes analysis and UNITLOD will always be used.

damping	<DAMPLOD, NODAMP> Default = DAMPLOD	DAMPLOD:	Generates a viscous damping residual vector for each viscous element based on the eigenvector of the viscous element.
		NODAMP:	Turns off the generation of the viscous damping residual vectors.

visc_inc	<set_id> Integer > 0 No default	set_id	Specifies SET identification number of a set of CBUSH elements for inclusion in the residual vector calculation (Comments 6 and 7).

visc_exc	<set_id> Integer > 0 No default	set_id	Specifies SET identification number of a set of CBUSH, CDAMP1-4, and CVISC elements for exclusion from the residual vector calculation (Comments 6 and 7).

option	<YES, NO> See comments for default.	YES:	Residual vectors are calculated.
		NO:	Residual vectors are not calculated.

Comments

1.	RESVEC can be requested for normal modes, modal complex eigenvalue analysis, modal frequency response, and modal transient response analysis subcases.

If the RESVEC does not exist in a subcase (and is not defined above the first subcase), the default is YES for modal frequency response and transient response analysis subcases, and the default is NO for all other applicable subcases. If a RESVEC card exists without the YES/NO option, the default is YES.

3.	If EXCITEID=SPCD is defined on RLOAD1/RLOAD2 or TLOAD1/TLOAD2, unit residual vectors for each enforced motion DOF are always computed, even if RESVEC=NO.

For normal modes analysis, the unit load method (type=UNITLOD) is applied to the degrees-of-freedom defined by USET and USET1 U6 entities. If the Lanczos eigensolver is used then RESVEC=YES must be present. If the AMSES or AMLS eigensolver is used, the USET and USET1 U6 residual vectors will always be calculated (even if RESVEC=NO is specified).

5.	Even though DAMPLOD and NODAMP may be defined inside each subcase, the setting from the last RESVEC data will be used for all of the modal complex eigenvalue analysis, modal frequency response, and modal transient subcases in the model.

6.	Duplicate VISC_INC and VISC_EXC arguments cannot be specified on a single RESVEC entry. Additionally, VISC_INC and VISC_EXC arguments cannot be defined simultaneously on a single RESVEC entry.

7.	VISC_INC and NODAMP arguments cannot be defined simultaneously on a single RESVEC entry.