7. Dimensions and units¶
Below is a table showing the dimensions and its associated units in AGX Dynamics. Where possible, SI units are being used. Many of the units are derived from the gravitational acceleration \(g\). It has a default value in AGX Dynamics of 9.80665 m/s2 and can be found in agx/Math.h.
Dimension |
Unit |
|---|---|
Acceleration |
m/s2 |
Angle |
rad |
Angular velocity |
rad/s |
Angular acceleration |
rad/s2 |
Cohesion |
Pa |
Compliance (rotational) |
rad/Nm |
Compliance (translational) |
m/N |
Damping * |
s |
Damping (rotational) |
Nms/rad |
Damping (translational) |
Ns/m |
Surface viscosity † |
m/s/N or s/kg |
Density |
kg/m3 |
Electric potential |
V |
Electric resistance |
Ohm |
Force |
N |
Length |
m |
Mass |
kg |
Moment of inertia |
kg m2 |
Pressure |
Pa |
Speed |
m/s |
Stiffness (rotational) |
Nm/rad |
Stiffness (translational) |
N/m |
Torque |
Nm |
Young’s Modulus |
Pa |
- *
Damping in AGX Dynamics refers to the damping time constant. It is a holonomic constraint-stabilization parameter for the time integration, expressed in seconds. It indicates roughly how quickly a holonomic constraint takes to dissipate energy and get back to the rest state; the damping effect usually scales with the simulation time step \(\Delta t\).
- †
Surface viscosity is a regulerization parameter for nonholonomic constraint that quantifies how easily a force generates velocity; the unit \(m/s/N\) = \(s/kg\) denotes velocity per unit force (mechanical mobility).