Impact Load Factor Calculator

Inspectable records

Ledger state

The current ledger marks this instrument verified clean within the source-bound verification corpus.

Area

Mechanical, Civil & Structural Engineering — Statics/Dynamics, Strength of Materials, Machine Design, Civil, HVAC, Vibration

Tranche

tranche-5

Evidence ID

t5-179

Ledger rows

1

No ledger note is attached.

Review findings

The amplification formula itself is standard under its stated idealized assumptions. Verdict is NEEDS_REVIEW because the specification claims a peak-stress output without providing static stress or another stress-calculation input, and because the exact sudden-load and falling-load application models are not fully defined.

Formula and scope findings

• The falling-load formula n=1+sqrt(1+2h/δst) is correct for an undamped, linear-elastic member when h is the drop distance before contact and δst is the static deflection caused by the falling load after it is applied.
• The sudden-load result n=2 at h=0 is correct only for an instantaneous step load on an initially stationary, linear, undamped elastic system; the specification does not define the load application model precisely.
• Dynamic deflection can be computed as δdynamic=n·δst, and peak stress can be computed as σdynamic=n·σst only when stress remains proportional to load. The listed inputs omit σst, so the claimed peak-stress output cannot be computed from the stated inputs.
• The phrase 'equivalent static load' is ambiguous: δst must correspond to the same load magnitude and structural configuration used for the impact calculation, not an unrelated static deflection.

Unit assumptions

• h and δst must use identical length units before evaluating 2h/δst; the ratio is dimensionless.
• Dynamic deflection uses the same length unit as δst.
• Static and peak stress must use the same stress unit; the numerical stress unit is preserved when multiplied by n.
• h is assumed nonnegative and δst is assumed strictly positive.
• The test vectors include σst as an additional required input because peak stress is otherwise under-specified.

Boundary hardening

BREAK_CLAIMED · SELF_FLAGGED

The formula is undefined when static deflection is zero, and a negative signed height can produce a negative square-root radicand unless the input is explicitly interpreted as a nonnegative drop-height magnitude.

Errata and corrections

No applied erratum is attached to this unique-name record.

Inspectable example

4 review vectors are recorded. One source-bound sample is shown below.

{
  "inputs": {
    "h": 0,
    "delta_st": 0.004,
    "static_stress": 80,
    "length_unit": "m",
    "stress_unit": "MPa"
  },
  "expected_outputs": {
    "impact_factor_n": 2,
    "dynamic_deflection": 0.008,
    "peak_stress": 160,
    "length_unit": "m",
    "stress_unit": "MPa"
  },
  "working": "2h/δst = 2·0/0.004 = 0. n = 1 + √(1 + 0) = 1 + 1 = 2. Dynamic deflection = n·δst = 2·0.004 = 0.008 m. Peak stress = n·σst = 2·80 = 160 MPa."
}

Related workflows

No source-defined multi-instrument workflow membership is recorded.

Sources and evidence

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

• VERIFIED_LEDGER.json · VERIFIED_CLEAN
• evidence-tranche5/tranche5-results.json
• BOUNDARY_HAZARD_CATALOG.json