COMPUTE THE PULSE INDEX BASED ON VEHICLE DISPLACEMENT AND ACCELERATION TIME-HISTORY DATA¶
Computes the Vehicle Pulse Index (VPI) from vehicle displacement and acceleration time-history curves, using a single-degree-of-freedom model parameterized by slack, stiffness, and mass. Use this worker to quantify crash pulse severity and structural aggressiveness for occupant safety assessments.
When to use¶
Classification: process.
Tagged: acceleration, crash_pulse, displacement, occupant_safety, pulse_severity, time_history, vehicle_pulse_index, vpi.
Inputs¶
| Label | ID | Type | Default | Required | Description |
|---|---|---|---|---|---|
| Vehicle Displacement | vehicle_displacement | vector | — | Vehicle displacement time-history curve (time vs. displacement, typically in mm or inches); used as the primary kinematic input to the VPI SDOF model. | |
| Vehicle Acceleration | vehicle_acceleration | vector | — | Vehicle acceleration time-history curve (time vs. acceleration, typically in g or mm/ms²); paired with displacement to drive the VPI calculation. | |
| Slack | slack | scalar | 1 | Slack (free travel) of the SDOF surrogate occupant model in displacement units (default = 1); represents the gap before contact force is engaged. | |
| Stiffness | stiffness | scalar | 1 | Stiffness of the SDOF surrogate occupant spring in force-per-displacement units (default = 1); controls the restraint load in the VPI model. | |
| Mass | mass | scalar | 1 | Mass of the surrogate occupant in the SDOF model in mass units (default = 1); scales the inertial force contribution to the pulse index. |
Outputs¶
| Label | ID | Type | Description |
|---|---|---|---|
| curve_vpi_output_1 | curve_vpi_output_1 | scalar | Scalar Vehicle Pulse Index (VPI) value computed from the supplied displacement and acceleration curves and SDOF parameters; higher values indicate a more aggressive crash pulse. |
Disciplines¶
- data.curve.pair
- engineering.crash.dynamics
- engineering.crash.occupant_safety
Runnable example¶
A runnable example is registered for this worker. Open the example workflow on the d3VIEW canvas: /api/workflow/example?id=curve_vpi
Auto-generated from transformation schema. Worker id: curve_vpi. Schema hash: 5eae8d01d864. Hand-curated docs in workerexamples/ override this page when present.