Verification & Validation

The Op³ V&V suite contains 140 active falsification gates across 15 test modules. All tests must pass before any commit reaches main.

Test summary

Module	Tests	Topic
`tests/test_code_verification.py`	4	Analytical closed-form references (Euler-Bernoulli, Rayleigh)
`tests/test_consistency.py`	4	Cross-path internal consistency
`tests/test_sensitivity.py`	5	Physical sensitivity invariants
`tests/test_extended_vv.py`	12	Damping, energy, reciprocity, units, coordinates, orthogonality
`tests/test_pisa.py`	9	PISA conic + 6x6 stiffness invariants
`tests/test_cyclic_degradation.py`	10	Hardin-Drnevich + Vucetic-Dobry
`tests/test_hssmall.py`	8	HSsmall constitutive wrapper + CSV round-trip
`tests/test_mode_d.py`	8	Mode D dissipation-weighted formulation
`tests/test_openfast_runner.py`	6	OpenFAST runner infrastructure
`tests/test_backlog_closure.py`	3	Static condensation, SACS round-trip, Mode B/C
`tests/test_uq.py`	13	MC propagation, PCE, Bayesian
`tests/test_op3_framework.py`	15	Framework integration, project I/O, visualization wiring
`tests/test_reproducibility.py`	6	Snapshot byte-identical reproduction
`scripts/calibration_regression.py`	4	Published-source frequency calibration
`scripts/test_three_analyses.py`	33	Eigenvalue + pushover + transient on 11 examples

Calibration regression

Example	Op³ f1 (Hz)	Reference (Hz)	Source	Error
NREL 5 MW fixed	0.316	0.324	Jonkman 2009 NREL/TP-500-38060	-2.5%
NREL 5 MW OC3 monopile	0.275	0.277	Jonkman & Musial 2010 NREL/TP-500-47535	-0.4%
SiteA 4 MW class tripod	0.235	0.244	PhD Ch. 5 field OMA	-3.7%
IEA 15 MW monopile	0.188	0.170	Gaertner 2020 NREL/TP-5000-75698	+10.6%

Standards conformance

DNV-ST-0126 audit (9 clauses x 4 examples = 36 checks): 35/36 PASS. The single failure is the SiteA tripod 1P frequency separation (6.8% < 10% required), which is a real engineering finding.

IEC 61400-3 audit (12 clauses x 4 examples = 48 checks): structural and foundation provisions all PASS; DLC coverage is partial as documented in the OpenFAST runner section.

Cross-validation against published benchmarks

In addition to the internal V&V tests above, Op³ has been cross-validated against 39 independent benchmarks from 20+ published sources, achieving a 92% verification rate (35/38 in-scope).

See Cross-Validation Against Published Benchmarks for the complete cross-validation report including OptumGX bearing capacity factors (0.8–7.8% error vs Vulpe 2015), foundation stiffness (3–26% vs Doherty 2005 / OxCaisson), and the Bothkennar field trial comparison (-21% vs measured K_r).