Products: ABAQUS/Standard ABAQUS/Explicit ABAQUS/Aqua
User subroutines allow advanced users to customize a wide variety of ABAQUS capabilities. Information on writing user subroutines and detailed descriptions of each subroutine appear online in the ABAQUS User Subroutines Reference Manual. A listing and explanations of associated utility routines also appear in that manual.
The available user subroutines for ABAQUS/Standard are as follows:
CREEP: Define time-dependent, viscoplastic behavior (creep and swelling).
DFLOW: Define nonuniform pore fluid velocity in a consolidation analysis.
DFLUX: Define nonuniform distributed flux in a heat transfer or mass diffusion analysis.
DISP: Specify prescribed boundary conditions.
DLOAD: Specify nonuniform distributed loads.
FILM: Define nonuniform film coefficient and associated sink temperatures for heat transfer analysis.
FLOW: Define nonuniform seepage coefficient and associated sink pore pressure for consolidation analysis.
FRIC: Define frictional behavior for contact surfaces.
GAPCON: Define conductance between contact surfaces or nodes in a fully coupled temperature-displacement analysis or pure heat transfer analysis.
GAPELECTR: Define electrical conductance between surfaces in a coupled thermal-electric analysis.
HARDINI: Define initial equivalent plastic strain and initial backstress tensor.
HETVAL: Provide internal heat generation in heat transfer analysis.
MPC: Define multi-point constraints.
ORIENT: Provide an orientation for defining local material directions or local directions for kinematic coupling constraints or local rigid body directions for inertia relief.
RSURFU: Define a rigid surface.
SDVINI: Define initial solution-dependent state variable fields.
SIGINI: Define an initial stress field.
UCORR: Define cross-correlation properties for random response loading.
UEL: Define an element.
UEXPAN: Define incremental thermal strains.
UEXTERNALDB: Manage user-defined external databases and calculate model-independent history information.
UFIELD: Specify predefined field variables.
UFLUID: Define fluid density and fluid compliance for hydrostatic fluid elements.
UFLUIDLEAKOFF: Define the fluid leak-off coefficients for pore pressure cohesive elements.
UGENS: Define the mechanical behavior of a shell section.
UHARD: Define the yield surface size and hardening parameters for isotropic plasticity or combined hardening models.
UHYPEL: Define a hypoelastic stress-strain relation.
UHYPER: Define a hyperelastic material.
UINTER: Define surface interaction behavior for contact surfaces.
UMASFL: Specify prescribed mass flow rate conditions for a convection/diffusion heat transfer analysis.
UMAT: Define a material's mechanical behavior.
UMATHT: Define a material's thermal behavior.
UMESHMOTION: Specify mesh motion constraints during adaptive meshing.
UMOTION: Specify motions during cavity radiation heat transfer analysis or steady-state transport analysis.
UMULLINS: Define damage variable for the Mullins effect material model.
UPOREP: Define initial fluid pore pressure.
UPRESS: Specify prescribed equivalent pressure stress conditions.
UPSD: Define the frequency dependence for random response loading.
URDFIL: Read the results file.
USDFLD: Redefine field variables at a material point.
UTEMP: Specify prescribed temperatures.
UTRACLOAD: Specify nonuniform traction loads.
UTRS: Define a reduced time shift function for a viscoelastic material.
UVARM: Generate element output.
UWAVE: Define wave kinematics for an ABAQUS/Aqua analysis.
VOIDRI: Define initial void ratios.