Mechanical APDL Structural Analysis Guide

To specify this solution con- Issue this CGROW command:

trol...

where value is the maximum crack exten-

sion

Because crack growth simulation can

be time-consuming, use this command

to stop the analysis when the specified

crack ext ension of interest has been

reached.

When a crack ext ends rapidly (for example, in cases of unstable crack growth), use smaller DTMAX and
DTMIN values to allow time for load rebalancing. When a crack is not growing, the specified time-
stepping controls are ignored and the solution adheres to standard time-stepping control.

12.1.1.4. Example: Crack Growth Set Definition

The following input example defines a crack growth set:

CGROW,NEW,1

CGROW,CPATH,cpath1

CGROW,FCOPTION,MTAB,5

CGROW,DTIME,1.0e-4

CGROW,DTMIN,1.0e-5

CGROW,DTMAX,2.0e-3

12.1.2. Crack Extension

In a crack growth simulation, a quantity of interest is the amount of crack extension. VCCT measures
the crack ext ension based on the length of the interface elements that have opened, as expressed by
the following equation and in the subsequent figure:

∆ =∑∆i

Figure 12.3: 2-D and 3-D Crack Extension

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VCCT-Based Crack Growth Simulation