Run a handling study
Open Handling Study, or choose Full Car under Vehicle Dynamics and the Handling Study analysis. The one applied assembly supplies sprung and four unsprung masses, CG-to-axle distances and tracks. Yaw inertia and four lateral tires are applied physical components; speed, steering, duration, step and initial conditions belong to the handling scenario.
The illustrative defaults use yaw inertia 2,500 kg m², each corner’s stiffness 80,000 N/rad and friction 0.9. These are generic examples, without measured calibration. Start at 15 m/s with a 0.02 rad steering step at 0.5 s, duration 5 s and step 0.002 s. Positive steering gives a leftward initial force and positive yaw.
Configure and apply a tire
Choose Configure lateral tire, edit stiffness and effective friction, then Apply to Vehicle. Edits remain separate drafts until Apply. Reload active tire discards that corner’s draft. The vehicle-corner lateral preview uses the same nominal flat load as handling; wheel and road displacement do not change it. Standalone reference inspection retains its separate vertical-contact load pathway. Longitudinal and combined-slip parameters remain inspection only.
Read and export results
Run executes a dedicated Worker. Six time plots show actual completed yaw rate, lateral acceleration, body sideslip, lateral velocity, steering and four tire-frame lateral forces. The XY trajectory uses equal metre scaling with start, end and heading direction. Sample tables remain available if plots fail. Edited inputs mark the preceding completed record stale; exports continue to describe that completed definition.
Global Export supplies all 46 SI channels as CSV and a provenance JSON containing the completed model, solver, physical parameters, scenario, channel frames and limitations. Handling PDF and video publishing are deferred. Global Save Project writes workspace-project.v2 without result arrays. Open restores physical inputs, scenario and drafts; Run reproduces deterministic Float64 outputs. Historical v1 projects migrate with generic handling components and retain their original analysis and 14-state Full-Car initial conditions.
Physics and operating envelope
Body +x is forward, +y left, +z up. Positive steer and yaw turn left. State [v,r,psi,X,Y] contains two dynamic states and three world kinematic states. Constant positive body speed U is prescribed. The equations are v̇=ΣFy/m−Ur, ṙ=ΣMz/Iz, ψ̇=r, Ẋ=Ucosψ−vsinψ and Ẏ=Usinψ+vcosψ.
Each rigid corner has velocity [U−ry,v+rx], rotated into its wheel frame. Slip α=atan2(Vy,abs(Vx)); the shared lateral tire law gives Fy=clamp(−Cαα,−μFz,+μFz). Rotation into body coordinates gives Fx=−sinδFy and Fy_body=cosδFy; moment xFy_body−yFx retains the track lever arm. A constraint supplies longitudinal action to maintain U.
All vehicle mass is lumped at the declared assembly CG. Flat static axle equilibrium gives each front load mgb/(2(a+b)), each rear load mga/(2(a+b)), with equal left/right support. This assumption is separate from the 7-DOF vertical model.
Inputs: U 2–60 m/s, steering ±0.35 rad, duration 0.01–30 s, step 0.0001–0.01 s and at most 100,001 samples. Additional damping-resolution and body bounds reject poorly resolved configurations. Runtime rejects non-forward corner motion below 0.5 m/s, slip beyond 60°, |r| above 3 rad/s, excessive lateral motion and nonfinite states. This is a numerical qualification envelope, not an experimentally established vehicle envelope.
Fixed RK4 splits exactly at a step-steering event; output steering is right-continuous. A short final interval preserves exact duration. Smooth convergence is fourth order in tested cases; clipping transitions require finer-step comparisons.
Boundaries and verification
Flat level ground, rigid body and fixed nominal loads only. No dynamic load transfer, suspension coupling, longitudinal or combined slip, wheel spin, drive/brake torque, camber thrust, aligning moment, tire relaxation, steering mechanism/compliance, powertrain, controllers, sensors, experimental correlation, OEM qualification or ADAS safety validation.
Independent numerical evidence compares the small-angle bicycle limit, separately coded nonlinear integration, force transformations, static equilibrium, saturation and timestep refinement.