Are there any SOLSH190 examples of analyzing a composite structure with debonding via Cohesive Zone Material (CZM) delamination?


Yes, please see the attached ANSYS 11.0 SP1 example showing the debonding of a composite channel beam structure using the contact element option of CZM. Both a temperature load and a concentrated force were applied to the channel using simply-supported boundary conditions. The details are as follows:

A 73-degree-F temperature increase (150 F - 77 F) was applied in the first load step and a 249.6-lbf vertical force (62.4 lbf in a quarter-symmetry model) in the second load step. The program progressed as far as it could with the given E-glass mechanical property data and CZM (Cohesive Zone Material) allowables. The force loading used a table array and is shown below:

nsel,r,node,,node(0.75,0,12) ! node at center of full web
cm,nfy,node ! create corresponding nodal component
*dim,webforc,table,3,1,1,time ! TIME = primary variable
webforc(0,1)=1.0 ! row 0, column 1 index header
webforc(1,0)=0.0,1.0,2.0 ! load step times
webforc(1,1)=0.0,0.0,-62.4 ! force ramped on in 2nd load step
f,nfy,fy,%webforc% ! 62.4 lbf on 1/4 model = 249.6 lbf equiv load

ANSYS 11.0 SP1 made it to 52.03% of the load, or roughly 130 lbf before failing to converge further. The delamination started long before this load, however. Please note that some of the material data and allowables were estimations, so it is critical that proper experimental testing be done to get the true mechanical property data and failure allowables. The latter requires testing at a lab familiar with fracture mechanics, as the CZM model is essentially a fracture mechanics approach.

Please note that the pinball radius (PINB) not only is used in determining near field contact; it also limits the range for the GAP information, so the 0.30" maximum gap reported in the last image just means that the gap reached that size and is probably larger. The PINB in this example was set to 10.0, which is a factor multiplied by the 0.03" calculatedpinball radius, for a product of 0.3". Finally, the /EXPAND command was used to show the entire channel, since only one-quarter of the structure was analyzed.





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