Match cyclic tests to OpenSees

Select a material model, adjust every required input, and compare the response and cumulative errors.

ACTIVE MODELSteel02Steel

1 Material model

Available OpenSees model

Giuffré–Menegotto–Pinto steel with isotropic strain hardening.

View parameter documentation ↗

Steel03 and Steel05 are not listed in the referenced OpenSeesPy material library. Steel4 is provided as the current advanced steel alternative.

2 Test-data generator

Common loading protocol

Strain-controlled symmetric coupon history with repeated yielding excursions.

8 amplitude stages703 data points

Regeneration retains the selected loading history and creates a new repeatable realization of measurement scatter.

3 Model parameters

Yield stressFyElastic modulusE0Hardening ratiobTransition radiusR0Transition coefficientcR1Transition coefficientcR2Compression hardeninga1Compression scalea2Tension hardeninga3Tension scalea4Initial stresssigInit

TEST–MODEL COMPARISON

Steel02 hysteresis

Prototype response

RMSE17.30

R²0.9962

Cumulative force error5.70%

Test cumulative energy168.82

Model cumulative energy163.09

Cumulative energy error3.39%

Force error = Σ|model − test| / Σ|test|Energy error compares total absolute trapezoidal work along both histories.

4 OpenSees material output

All parameters required for the selected material are shown below and included in the generated command.

Fy334

E0182816

b0.01101

R016.453

cR10.85378

cR20.11384

a10.02285

a20.91408

a30.01645

a40.91408

sigInit0

ops.uniaxialMaterial('Steel02', 1, 334, 182816, 0.01101, 16.453, 0.85378, 0.11384, 0.02285, 0.91408, 0.01645, 0.91408, 0)

5 Test-data preview

Representative points from the regenerated synthetic dataset using Steel coupon low-cycle.

703 rows

Step	Input	Test response	Model response	Error
0	0.000000	0.000	0.000	0.000
100	-0.000203	-60.519	-57.168	3.351
201	0.002433	105.170	104.685	-0.485
301	0.002433	326.597	321.058	-5.539
401	-0.003244	182.976	197.282	14.307
501	-0.007300	-393.395	-369.629	23.766
602	0.001622	-362.417	-354.954	7.463
702	0.000000	380.226	359.896	-20.330

Development note: Steel02 has the most direct browser implementation. All other response engines are transparent calibration scaffolds and command generators; validate them against direct OpenSees/OpenSeesPy execution before research or design use.