modelLineForceBase
Base model for line force elements
Extends from PartialTwoFrames (Base model for components providing two frame connectors + outer world + assert to guarantee that the component is connected).
Information
All line force elements should be based on this base model. This model defines frame_a and frame_b and computes the (guarded) relative distance s. An assertion is raised if the relative distance length became smaller as parameter s_small.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Advanced | |||
| SI.Distance | s_small | 1e-10 | Prevent zero-division if distance between frame_a and frame_b is zero |
| Advanced › If enabled, can give wrong results, see MultiBody.UsersGuide.Tutorial.ConnectionOfLineForces | |||
| Boolean | fixedRotationAtFrame_a | false | = true, if rotation frame_a.R is fixed (to directly connect line forces) |
| Boolean | fixedRotationAtFrame_b | false | = true, if rotation frame_b.R is fixed (to directly connect line forces) |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Interfaces.Frame_a | frame_a (from PartialTwoFrames) | Coordinate system a fixed to the component with one cut-force and cut-torque | |
| Interfaces.Frame_b | frame_b (from PartialTwoFrames) | Coordinate system b fixed to the component with one cut-force and cut-torque |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| SI.Distance | length | Distance between the origin of frame_a and the origin of frame_b | |
| SI.Position | s | (Guarded) distance between the origin of frame_a and the origin of frame_b (>= s_small)) | |
| SI.Position[3] | r_rel_0 | Position vector from frame_a to frame_b resolved in world frame | |
| Real[3] | e_rel_0 | Unit vector in direction from frame_a to frame_b, resolved in world frame |