TRUE TO ENG¶
Converts one or more true stress–strain curves to engineering (nominal) stress–strain curves using the inverse of the standard logarithmic relations, with optional Poisson’s-ratio correction and tension/compression mode selection. An optional post-necking failure model can be appended uniformly to every input curve, truncating at the peak and adding a concave-down power-decay segment that terminates at a user-specified engineering failure point.
When to use¶
Classification: process.
Tagged: compression, curve-conversion, failure-model, material-testing, poissons-ratio, post-necking, stress-strain, tension.
Inputs¶
| Label | ID | Type | Default | Required | Description |
|---|---|---|---|---|---|
| True Stress Vs Strain Curve | truestressstraincurves | vector | — | One or more true stress vs. true strain curves (dimensionless strain, stress in consistent pressure units) to be converted to engineering stress–strain; accepts multiple curves in a single batch. | |
| Poisson’s Ratio | poissons_ratio | scalar | 0.0 | Poisson’s ratio of the material (dimensionless scalar, e.g. 0.3 for steel). The 0.0 default uses the incompressible plastic limit (the ν=0.5 result) for backward compatibility with existing workflows; set to the material’s actual ν for elastic-regime conversion. Has no effect when ‘Apply Poisson Correction’ is set to ‘No’. | |
| Tension/Compression Flag | tension_compression_flag | text | tension | Specifies whether the input curves represent tensile (‘tension’) or compressive (‘compression’) data, controlling the sign convention used in the conversion; default is ‘tension’. | |
| Model Post-Necking Failure | model_failure | select | no | When set to ‘Yes’, appends a post-necking failure extension to every converted curve, truncating at the curve’s own peak and adding a concave-down power-decay segment down to (Failure Strain, Failure Stress); default ‘No’ leaves curves as-is. | |
| Failure Strain (eng) | failure_strain | scalar | 0 | Engineering strain at fracture/failure (dimensionless); must exceed each curve’s necking (peak) strain — used only when Model Post-Necking Failure is ‘Yes’; default 0.0. | |
| Failure Stress (eng) | failure_stress | scalar | 0 | Engineering stress at fracture/failure (same pressure units as input curves); defines the terminal stress of the power-decay segment — used only when Model Post-Necking Failure is ‘Yes’; default 0.0. | |
| Post-Necking Exponent (n) | post_necking_exponent | scalar | 2 | Power n in sigma(t) = sigma_u - (sigma_u - sigma_f) * t^n. n = 2 (default) matches typical ductile metals. | |
| Apply Poisson Correction | apply_poisson_correction | select | yes | When ‘Yes’ (default), corrects the cross-section using the Poisson’s Ratio above (standard true-to-eng conversion for metals and polymers). When ‘No’, returns engineering stress equal to true stress with no area correction — use for foams or other materials with effectively zero lateral contraction. |
Outputs¶
| Label | ID | Type | Description |
|---|---|---|---|
| curve_truetoengstress_output_1 | curve_truetoengstress_output_1 | vector | Converted engineering stress vs. engineering strain curve(s) — one output curve per input true stress–strain curve, with the optional post-necking failure extension appended if requested. |
Disciplines¶
- data.curve.transform
- engineering.material.characterization
Runnable example¶
A runnable example is registered for this worker. Open the example workflow on the d3VIEW canvas: /api/workflow/example?id=curves_truetoengstress
Auto-generated from transformation schema. Worker id: curves_truetoengstress. Schema hash: 3d9d5a2e6039. Hand-curated docs in workerexamples/ override this page when present.