Main Help → All Commands → Explicit Cracks → GrowCrackArc
The GrowCrackArc
command is used when defining cracks in an MPM problem.
GrowCrackArc (x1),(y1),(x2),(y2),(segs),(ang1),(ang2),<(mat)>,<(tract)>
where
(x1)
, (y1)
, (x2)
, and (y2)
define the (xmin, ymin) and (xmax, ymax) coordinates, respectively of the rectangle enclosing and oval (or (Rmin, Rmin) and (Zmax, Zmax) if axisymmetric) in length units. The arc will be defined along that oval.(segs)
is the number of crack segments to create along the arc. The recommendation is that crack segment lengths be comparable to, or less than, the width of the elements in the mesh.(ang1)
and (ang2)
define starting and end angles for the arc (in degrees). The arc is drawn in the counter-clockwise direction and angle = 0 corresponds the point on the arc in the positive x
direction.(mat)
can be used to define a material ID for a previously defined material that contains the crack tip at the end of the crack or can be "exterior
" to indicate a crack to the edge of the body (see OSUPDocs wiki for details on "exterior
" cracks). Crack propagation is only possible when the crack tips have a material ID. If the material ID is omitted, the MPM calculations will correctly model that crack, but no propagation or fracture parameter calculations will occur. A crack tip material is only needed if the GrowCrackArc
command is the last crack definition command for the current crack.(tract)
can assign a traction law to all particles on the line. Set (tract)
to a material ID for a previously defined traction law material. To set a traction law material but no crack tip material in (mat)
, set (mat)
to "0" (or any invalid material ID).Because the control points for the arc are the boundaries of the oval's rectangle and not the starting and ending points of the resulting arc, linking arcs with points and lines may cause jumps in the crack geometry. If these jumps are not correct, you can precede or follow the arc with GrowCrack
commands (or the NewCrack
command if the GrowCrackArc
command is the first crack shape) having their points as the starting or ending point of the resulting arc.
GrowCrackArc
command is only allowed for MPM analyses.