{"id":431251,"date":"2025-05-10T18:37:02","date_gmt":"2025-05-10T18:37:02","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/czm-contact-setup-between-solid-and-shell-elements-in-mechanical\/"},"modified":"2025-05-10T18:37:02","modified_gmt":"2025-05-10T18:37:02","slug":"czm-contact-setup-between-solid-and-shell-elements-in-mechanical","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/czm-contact-setup-between-solid-and-shell-elements-in-mechanical\/","title":{"rendered":"CZM contact setup between solid and shell elements in Mechanical"},"content":{"rendered":"

<p><span style=”font-size: 12pt;”>\"\"\"\"<br>\"\"<br>Hi everyone, I’m trying to implement a Cohesive Zone Model (CZM) in ANSYS Mechanical to simulate adhesive bonding between a shell element (mid-surface airfoil) and a solid body (square tube).<\/span><br data-start=”499″ data-end=”502″><span style=”font-size: 12pt;”>However, I’m struggling with contact activation and realistic adhesive behavior.<\/span><br><span style=”font-size: 12pt;”>Setup: <\/span><br><span style=”font-size: 12pt;”>- The airfoil is modeled as a shell (mid-surface) with 1 mm thickness, using Offset Type = Middle to activate the shell thickness effect in contact.<\/span><br><span style=”font-size: 12pt;”>- Contact is defined as bonded (formulation: Augmented Lagrange), with contact shell face = bottom.<\/span><br><span style=”font-size: 12pt;”>- Fracture behavior is activated via Contact Debonding = CZM, with material data from adhesive manufacturer “3M”. <\/span><span style=”font-size: 12pt;”>The shell face is the contact, and the solid outer wall of the square tube is the target.<\/span><br><span style=”font-size: 12pt;”>Problem:<\/span><br><span style=”font-size: 12pt;”>- In the Contact Tool, the contact side appears as “Closed”, but the target side remains inactive<\/span><br><span style=”font-size: 12pt;”>- The geometric gap is 0.5 mm, which matches the expected half of the shell thickness<\/span><br><span style=”font-size: 12pt;”>- The default pinball radius is too small, and a warning in output always appears: “Normal separation at maximum traction for debonding (…) is greater than pinball radius (…) debonding calculations will be bypassed…” <br>- When I set the pinball radius to 0.6 mm (to match the gap), the warning still appears <br>- I’ve read that using a bonded contact with an enlarged pinball radius can artificially stiffen the interface and suppress damping behavior that adhesives would normally provide. So I’m unsure if this is even correct modeling.<br>- I also tried flipping contact\/target sides, but the same result.<br>- Adjust to Touch is not available for bonded or CZM contact types.<br>- If I change the shell offset to bottom to match the contact geometry better, then Ansys no longer considers the shell thickness in the contact behavior.<br><br>So my question is how I can define the contact between a shell mid-surface and a solid face properly and avoid the solver warning. What I really want is to make sure the contact activates as expected and that the adhesive behavior, like debonding and frictional stress, is captured realistically. <br>I should mention that I already tested the same adhesive using CZM between two solid bodies, and in that case, everything worked fine, and the results matched the datasheet.<br><\/span><\/p><\/p>\n","protected":false},"template":"","class_list":["post-431251","topic","type-topic","status-publish","hentry","topic-tag-adhesive","topic-tag-czm","topic-tag-midsurface","topic-tag-shell-elements"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t