Source: https://guthlabs.ai/docs/instruments/axial-stress-strain-calculator/mechanism/

instrument mechanism / verified-clean

# Axial Stress & Strain Calculator mechanism

The inspectable method record for Axial Stress & Strain Calculator, kept separate from implementation and qualification.

Status: **VERIFIED_CLEAN**Lifecycle: **verified-clean**

## Model scope

NEEDS_REVIEW because the exact ambiguity is that the spec provides no units for P, A, L, or E and does not state the sign convention for P. The empty honest_label should be populated with the assumptions and limitations: uniform prismatic member, concentric axial load, linear elastic behavior, small strain, and required unit consistency.

No additional formula finding is recorded.

## Units and conventions

- P is axial force, A is cross-sectional area, L is initial gauge length, and E is Young's modulus.

- P and A must use compatible force and area units so that σ=P/A has stress units.

- E must use the same stress units as σ.

- L and δ must use the same length units.

- ε is dimensionless.

- The formulas assume a prismatic member with uniform area, concentric axial loading, linear elastic material behavior, small strain, and negligible effects from self-weight or local stress concentrations.

## Inspectable vector

One of 4 source-bound review vectors:

````
{
  "inputs": {
    "P": 20000,
    "P_unit": "N",
    "A": 400,
    "A_unit": "mm^2",
    "L": 2000,
    "L_unit": "mm",
    "E": 200000,
    "E_unit": "N/mm^2"
  },
  "expected_outputs": {
    "σ": "50 MPa",
    "ε": "0.00025",
    "δ": "0.5 mm"
  },
  "working": "σ=P/A=20000/400=50 N/mm^2=50 MPa. ε=σ/E=50/200000=0.00025. δ=PL/(AE)=(20000×2000)/(400×200000)=40000000/80000000=0.5 mm."
}
````

## Failure boundary

**BREAK_CLAIMED** · SELF_FLAGGED

An input of A=0 makes sigma and delta undefined through division by zero; the calculator should reject it rather than expose non-finite JavaScript results.

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/axial-stress-strain-calculator/>)[03**Implementation**](<https://guthlabs.ai/docs/instruments/axial-stress-strain-calculator/implementation/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/axial-stress-strain-calculator/qualification/>)

## Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

- `VERIFIED_LEDGER.json`

- `evidence-tranche4/tranche4-results.json`

- `BOUNDARY_HAZARD_CATALOG.json`