Hey structures folks. Context: Looking at aluminum homebuilt spars, webs tend to be made of a stack-up of relatively thin sheets, increasing in count towards the root, and going down to single sheet (minimum gauge) at the tip. Totally understand the structural goals here of varying thickness, and understand the advantages of part availability, easy tapering, etc. I can also imagine building a similar structure where at some inboard station rather than adding several sheets, a single thicker plate is added, maybe machined for thickness or maybe not. In the extreme case, this would be a (machined) plate for the inboard sections, joined to a sheet for the outboard sections. Comfortable thinking about manufacturing challenges, time, cost, etc, although non-obvious insights always valuable.
Getting to the question: Besides manufacturability concerns, are there reliability and/or failure mode concerns that favor one approach over the other? I can see the sheet approach as favorable for reducing crack propagation, giving redundancy for a single crack that does propagate, etc; but I can also see concerns around more surfaces meaning more points for (hidden!) corrosion to start.
Getting to the question: Besides manufacturability concerns, are there reliability and/or failure mode concerns that favor one approach over the other? I can see the sheet approach as favorable for reducing crack propagation, giving redundancy for a single crack that does propagate, etc; but I can also see concerns around more surfaces meaning more points for (hidden!) corrosion to start.
