TRUE TO ENG¶
Converts a true stress–strain curve to its engineering (nominal) equivalent using the standard inverse relationships, with optional Poisson’s ratio correction and tension/compression mode selection. When post-necking failure modelling is enabled, the converted engineering curve is truncated at its peak (necking point) and extended to a user-specified failure point via a concave-down power-law decay.
When to use¶
Classification: process.
Tagged: compression, curve_transform, engineering_stress, failure_model, mat_24, necking, poissons_ratio, post_necking.
Inputs¶
| Label | ID | Type | Default | Required | Description |
|---|---|---|---|---|---|
| True Stress Vs Strain Curve | truestressstraincurve | vector | — | True stress vs. true strain curve to be converted (dimensionless strain, stress in consistent units); supplied as an (x, y) vector pair — leave empty only if chaining from an upstream curve output. | |
| Poisson’s Ratio | poissons_ratio | scalar | 0.0 | Poisson’s ratio of the material (dimensionless, e.g. 0.3 for steel); used to correct the lateral strain contribution during conversion — default 0.0 omits the correction. | |
| Tension/Compression Flag | tension_compression_flag | text | tension | Indicates whether the input curve represents a tension (‘tension’) or compression (‘compression’) test; controls the sign convention applied during the true-to-engineering conversion — default is ‘tension’. | |
| Model Post-Necking Failure | model_failure | select | no | Set to ‘Yes’ to truncate the converted engineering curve at its peak stress (necking onset) and append a concave-down power-law decay to the failure point; default ‘No’ returns the converted curve unmodified. | |
| Failure Strain (eng) | failure_strain | scalar | 0 | Engineering strain at failure (dimensionless); must exceed the necking strain — only used when Model Post-Necking Failure is ‘Yes’, default 0.0. | |
| Failure Stress (eng) | failure_stress | scalar | 0 | Engineering stress at failure (same units as the input curve); defines the terminal stress value of the appended power-law tail — only used 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 with t = (eps - eps_u) / (eps_f - eps_u). n = 2 (default) gives a zero-slope, concave-down decay that matches typical ductile metals; higher n keeps the curve flatter near necking. |
Outputs¶
| Label | ID | Type | Description |
|---|---|---|---|
| curve_truetoengstress_output_1 | curve_truetoengstress_output_1 | vector | Converted engineering stress vs. engineering strain curve (same stress units as the input); includes the optional post-necking failure tail when Model Post-Necking Failure is ‘Yes’. |
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=curve_truetoengstress
Auto-generated from transformation schema. Worker id: curve_truetoengstress. Schema hash: 7426ea59910e. Hand-curated docs in workerexamples/ override this page when present.