Calculates and prints linearized stresses along a section path.
In-plane (X-Y) average radius of curvature of the inside and outside surfaces of an axisymmetric section. If zero (or blank), a plane or 3-D structure is assumed. If nonzero, an axisymmetric structure is assumed. Use any large number (or -1) for an axisymmetric straight section.
Through-thickness bending stresses key for an axisymmetric
RHO ≠ 0):
Include the thickness-direction bending stresses.
Ignore the thickness-direction bending stresses.
Include the thickness-direction bending stress using the same formula as the Y (axial direction ) bending stress. Also use the same formula for the shear stress.
You may want to linearize the stresses through a section and separate them into categories for various code calculations. PRSECT calculates and reports linearized stresses along a section path. The linearized stresses are also separated into membrane, bending, membrane plus bending, peak, and total stress categories.
Define your section path (PATH and PPATH with the NODE
option). Your path must lie entirely within the selected set of elements (that is, no element
gaps may exist along the path). PATH and PPATH only
retrieve the two end nodes; the path data is not retained. The section path is defined by the two
end nodes, and by 47 intermediate points that are automatically determined by linear
interpolation in the active display coordinate system (DSYS). The number and
location of the intermediate points are not affected by the number of divisions set by
Your linearized component stress values are obtained by interpolating each element’s average corner nodal values along the section path points within each path element. PRSECT reports the linearized component and principal stresses for each stress category at the beginning, mid-length, and end of the section path. PRPATH can be used to report the total stresses at the intermediate points.
Section paths can be through any set of solid (2-D plane, 2-D axisymmetric or 3-D) elements; however, section paths are usually defined to be through the thickness of the structure and normal to the inner and outer structure surfaces. Section paths (in-plane only) can also be defined for shell element structures.
RHO option is set to indicate the axisymmetric option
(non-zero), PRSECT reports the linearized stresses in the section coordinates
(SX – along the path, SY – normal to the path, and SZ – hoop direction). If the
RHO option is set to indicate the 2-D planar or 3-D option (zero or
blank), PRSECT reports the linearized stresses in the active results
coordinate system (RSYS]. If the
RHO option is zero
or blank and either RSYS, SOLU or RSYS, -1 are active, the
linearized stresses are calculated and reported in the global Cartesian coordinate system.
Linearized stress calculations should be performed in a rectangular coordinate system. Principal stresses are recalculated from the component stresses and are invariant with the coordinate system as long as SX is in the same direction at all points along the defined path. The PLSECT command displays the linearized stresses in the same coordinate system as reported by PRSECT.
Stress components through the section are linearized by a line integral method and separated into constant membrane stresses, bending stresses varying linearly between end points, and peak stresses (defined as the difference between the actual (total) stress and the membrane plus bending combination).
For nonaxisymmetric structures, the bending stresses are calculated such that the neutral axis is at the midpoint of the path. Axisymmetric results include the effects of both the radius of revolution (automatically determined from the node locations) and the in-plane average radius of curvature of the section surfaces (user input).
For axisymmetric cases, Mechanical APDL calculates the linearized bending
stress in the through-thickness direction as the difference between the total outer fiber stress
and the membrane stress if
KBR = 0. The calculation method may be
conservative for locations with a highly nonlinear variation of stress in the through-thickness
direction. Alternatively, you can specify
KBR = 2 to calculate the
bending stress using the same method and formula as the Y (axial direction) bending stress. For
more information, see the discussion of axisymmetric cases (specifically Equation 17–40)
in the Mechanical APDL Theory Reference.
Portions of this command are not supported by PowerGraphics (/GRAPHICS,POWER].