Composite action due to frictional resistance at ULS ?

[kww2008]

For a timber deck lightly clamped to a steel I beam, any possibility of partial composite action resulted from the friction resistance between timber deck and steel beam at ultimate limit state ? Non destructive testings show that the neutral axis (under live traffic load) lies above the mid height of the steel section; this suggests some composite action at test load level. Will this frictional resistance be present at collapse load to give partial composite action (thus increasing the capacity at ULS when compared with the capacity from the steel and timber sections acting independent of each other)?

 

[wiktor]

At collapse load displacment will be so large that "light clamping" may be not sufficient to retain any frictional resistance. I will not count on the partial composite action in this case.