VDLOAD

Number of points to be processed in this call to VDLOAD.

Number of coordinate directions: 2 for two-dimensional models, 3 for three-dimensional models. The model will be considered three-dimensional if any three-dimensional elements are defined (including SPRINGA elements).

Value of time since the step began.

Value of total time. The time at the beginning of the step is given by totalTime − stepTime.

Current value of the amplitude referenced for this load (set to unity if no amplitude is referenced). You must multiply the load by the current amplitude value within the user subroutine if the amplitude is required.

Current coordinates of each point for which the load is to be calculated.

Current velocity, displacement, and previous acceleration at each point for which the load is to be calculated. The array is defined as vua(1,1,1) for the first component of the velocity array, vua(1,1,2) for the first component of the displacement array, and vua(1,1,3) for the first component of the acceleration array. The acceleration values correspond to the end of the previous increment.

Current orientation of the face, edge, pipe, or beam for pressure type loads (not applicable for body force type loads). The second dimension indicates the vector, and the third dimension indicates the components of that vector. For faces (pressures on three-dimensional continuum, shell, and membrane elements), the first and second vectors are the local directions in the plane of the surface and the third vector is the normal to the face, as defined in Conventions. For solid elements the normal points inward, which is the opposite of what is defined in the conventions; for shell elements the normal definition is consistent with the defined conventions. For edges (pressures on two-dimensional continuum elements and two-dimensional beams and pipes), the first vector is the normal to the edge, the second vector is the tangent to the edge, and, if ndim=3, the third vector will be a unit normal in the out-of-plane direction. For three-dimensional beam and pipe elements, the first and second vectors are the local axes ( ${\mathbf{n}}_1$ , ${\mathbf{n}}_2$ ) and the third vector is the tangent vector ( $\mathbf{t}$ ), as defined in Beam Element Cross-Section Orientation.

For a discrete element analysis using PD3D elements, the first column of the array is the radius of the element.

Key that identifies the distributed load type. The load type might be a body force, a surface-based load, or an element-based surface load. For element-based surface loads, this variable identifies the element face for which this call to VDLOAD is being made. See About the Element Library for element load type identification. This information is useful when several different nonuniform distributed loads are being imposed on an element at the same time. The key is as follows:

Surface name for a surface-based load definition (JLTYP=0). For a body force or an element-based load the surface name is passed in as a blank.