Surf layer delamination (fall-off), based on density or temperature

[shostikk]

A layer and all layers before it can be made to disappear accoring to FALLOFF_TMP or FALLOFF_DENSITY (layer-by-layer parameter), compared at the last cell of a layer. Can be used for delamination of cross-laminated timber.

[shostikk]

Ping @drjfloyd

[mcgratta]

There is currently a parameter called MINIMUM_LAYER_THICKNESS. Would it be better to call this parameter MINIMUM_LAYER_DENSITY ?

[shostikk]

Can't remember what it is used for. Not related to this falloff feature, however. ?

[mcgratta]

My comment is simply about the name. Should we call the parameter MINIMUM_LAYER_DENSITY to be consistent with MINIMUM_LAYER_THICKNESS?

[shostikk]

Aa - maybe not. This is density or temperature threshold at layer interface, simulating a failure of adhesive bond. Temperature criteria could be seen from glue TGA or CLT DTMA test. Density criterion could relate to charring-induced weakening of the interface.

FALLOFF maybe doesn't tell enough....?

Layer_density sounds like somehow the whole layer is considered.This is LOCAL criterion

[mcgratta]

FALLOFF is a bit vague. Should we just use the word DELAMINATION to avoid confusion?

[shostikk]

I think DELAMINATION_TMP is good. Or DELAMINATION_DENSITY. We stopped using 'delamination' when we saw that delamination can occur also without falloff (just gap formation) but I think it is commonly used term.

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________________________________ From: Kevin McGrattan ***@***.***> Sent: Thursday, July 3, 2025 9:50:11 PM To: firemodels/fds ***@***.***> Cc: Hostikka Simo ***@***.***>; State change ***@***.***> Subject: Re: [firemodels/fds] Surf layer delamination (fall-off), based on density or temperature (PR #14823) [https://avatars.githubusercontent.com/u/11333911?s=20&v=4]mcgratta left a comment (firemodels/fds#14823)<#14823 (comment)> FALLOFF is a bit vague. Should we just use the word DELAMINATION to avoid confusion? — Reply to this email directly, view it on GitHub<#14823 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/ADBAEIBALHAUKBX3B5UBEY33GV3OHAVCNFSM6AAAAACAXLJ2M2VHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZTAMZTGI2DOMZVGM>. You are receiving this because you modified the open/close state.Message ID: ***@***.***>