Skip to content
Marc & Structures
Index

Save your progress

Enter your email and we will send a secure sign-in link. There is no password and the first link creates your account.

Debugging ~6 min · ~24 min remaining

Five false equilibria

Identify partial sums, incorrect sets, and selections that hide reactions.

Bug hunting — Five false balances

Open 06_bug_hunt.mac and diagnose each case:

  1. Spread selection: An attempt is made to solve without recovering the entire model.
  2. Missing set: reactions are queried without activating a result set.
  3. Wrong sign: reaction and charge are compared as if they had the same meaning.
  4. global FSUM: a sum close to zero is interpreted as absence of reaction.
  5. Non-existent moment: wanted RF,MZ in nodes without rotation and the force torque is ignored.

Don't fix the code first. For each error write: symptom, physical cause, state of MAPDL involved and minimal test that would confirm the diagnosis.

Quick check

FSUM runs with an accidental partial selection. What is the risk?

Professional incident

Incident M06: diagnose before editing

SOLVE succeeds, but force or moment does not close.

Execution cycle

  1. 1 Run the broken script in a clean folder.
  2. 2 Preserve the original .out.
  3. 3 Write one causal hypothesis and make one change.
  4. 4 Compare evidence before and after.
Evidence to retain

Graduated hints

1 · Concept hint

Find the first broken contract.

2 · Command hint

Inspect state related to PRRSOL and FSUM.

3 · Explained solution

Compare with the module deliverable and explain why the corrected state restores the contract.

Your reflection stays in this browser.