| File | What | When |
|---|---|---|
W07_lecture.html
(.qmd source) |
Lecture slides — Parts A, B, C, D | in class |
W07_lab.ipynb
(Colab) |
In-class lab: a Warren truss against the method of joints (and what one cell too many or one rank too many does), shear locking of a Timoshenko cantilever and its cure, a frame in bending and torsion, the local frame of a portal frame, the geometrically exact rod rolled into a circle and a helix (exact answers), a large-deflection cantilever against the elastica, LLM exercise (a space truss) | in class (≈ 80 min) |
W07_HW7.ipynb
(Colab) |
HW7 — the truss singularity, the locked element and rotations about a fixed axis (theory), an indeterminate truss with lack of fit, section orientation in an L-frame, locking against slenderness, convergence of rod elements on the helix, a stiff rod and SNES’s divergence test, the source’s load case done right, an LLM-generated rod script with defects | due before Week 8 |
../dolfinx_0.11_api_reference.md |
DOLFINx 0.11 API reference sheet — §16n trusses and Timoshenko frames on a 1D mesh · §16o the geometrically exact rod — paste it into your LLM | always |
Open a notebook in Colab: click its link on the
course page or below — it opens in Colab; then File → Save a copy in
Drive and work on that copy. (Or upload the .ipynb to
Google Drive → right-click → Open with → Google Colaboratory.)
Run the setup cell first (≈ 3–5 min); re-run it after every runtime
restart.
Where code can run: basix,
ufl, dolfinx, petsc4py are used
only inside %%fenicsx cells. Ordinary cells have NumPy and
matplotlib only. The models are two modules written by
%%writefile /tmp/fnx/frame.py and
/tmp/fnx/rod.py cells — run both first. Trusses and
frames run with -np 1: where three or more members
meet at a joint, DOLFINx 0.11 duplicates the joint when its members land
on different MPI ranks (the lab shows it). The rod is a chain and runs
on two ranks.
Before submitting: Runtime → Restart session and
run all, fill in the AI-usage log, download the
.ipynb. An error inside a %%fenicsx cell does
not stop Run all: the traceback is printed and
the next cell runs anyway. Scroll through every output before you
submit. (The first cell of HW7 Q4 runs an LLM-generated script that is
meant to be wrong.) The whole HW runs in under a minute locally
(a few minutes on Colab).
Week 8 starts with the midterm (first half, Weeks 1–7). There is no separate quiz; practice questions on this week’s material are handed out for the review.