Does a patch-averaged stress change what manufacturing rules cost a sized bracket?
research/simdesign-patchsearch
Repeats the process-rule bracket search with a 3 mm patch-averaged stress instead of the peak: the ordering of mass prices (casting > CNC > laser ≈ FDM) holds, the laser price spread across seeds shrinks from 0.16 to under 0.005, and designs overshoot their limit by 2–12% on a fine mesh against 19–34% for the peak (stylised, assumed values, uncalibrated limit).
What it found
The minimum-mass bracket search under FDM, CNC-routing, laser-cutting and casting rules is repeated with a 3 mm patch-averaged stress in place of the peak element stress, using the same numeric limit, then every design is re-solved on a fine check mesh (h = 0.55 mm). The ordering of the mass prices survives (casting 1.35, CNC 1.23–1.27, laser 1.03–1.05, FDM 1.0), and the laser-cutting price, which varied from 0.99 to 1.15 across three seeds under the peak measure, varies by under 0.005. Patch-searched designs exceed the limit by 2–12% on the fine mesh, against 19–34% for peak-searched designs, but they are lighter only because the same numeric limit is a looser test; the patch limit is uncalibrated. Three seeds, assumed rules and material, stylised 2D.
A figure from its own output
Paper, code and results
More in Simulation-first design
- Is the shrinking laser-cutting price scatter under the patch stress caused by the near-sharp fillet floor?Tests whether a near-sharp fillet floor explains the laser-cutting price scatter seen in
simdesign-patchsearch: it does not (peak-stress designs already use 7.6–14.3 mm fillets, so floors of 0.2 and 1 mm give identical designs); the patch-stress price is steady (sd 0.006–0.011) at every floor, and the cause of the peak scatter is not identified (negative, five seeds, stylised). - Where does the peak-stress price scatter of laser-cutting rules come from?Follow-up to
simdesign-filletfloor: the peak-stress price scatter of laser-cutting rules (sd 0.063) sits in the 2 mm gauge sub-search, not the fillet floor; a four-times search budget cuts it to 0.025 but not monotonically, so several nearby optima are plausible but not shown (five seeds, stylised). - Does a patch-averaged stress give a mesh-converged stress concentration for a bolt hole?Patch-averaged stress for a bolt hole in a tension strip: nearly settled under mesh refinement already, matches Kirsch's disc averages, needs its own limit (stylised).
- How far below the exact stress concentration does a finite-element peak stress sit, and how fast does it close?Checks the finite-element peak stress at a circular hole against Kirsch's exact 3× concentration: the element-centroid peak sits 27% (coarse) to 1.1% (fine) below it and closes only at first order, while hole-edge vertex values are within 1% (stylised).
- What causes the peak-stress price scatter of laser-cutting rules in the bracket search?The peak-stress price scatter of laser-cutting rules is a missed search at the narrow 2 mm gauge (1 seed in 20), not a cost of the rules; stylised, mesh effects untested.
- Do search restarts remove the missed 2 mm sub-search in the laser-cut bracket problem?A second DE restart or a doubled population removes the missed 2 mm sub-search (0 misses in 40 runs against 1 in 20 at baseline) and shifts results to the lighter of two mass groups at about twice the cost; stylised, 2.5 mm search mesh only.
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Produced with AI assistance (Claude). Results are from the code in this repository and are simulated or stylised unless the abstract says otherwise; nothing here implies affiliation with or endorsement by any lab, researcher or company cited. MIT licensed.