Revolved Solid

Solid revolved element with geometry, inertia, and color

Libraries:
Simscape / Multibody / Body Elements

Description

The Revolved Solid block is a rotational sweep of a general cross section with geometry center coincident with the [0 0] coordinate on the cross-sectional XZ plane and revolution axis coincident with the reference frame z axis.

The Revolved Solid block adds to the attached frame a solid element with geometry, inertia, and color. The solid element can be a simple rigid body or part of a compound rigid body—a group of rigidly connected solids, often separated in space through rigid transformations. Combine Revolved Solid and other solid blocks with the Rigid Transform blocks to model a compound rigid body.

A reference frame encodes the position and orientation of the solid. In the default configuration, the block provides only the reference frame. A frame-creation interface provides the means to define additional frames based on solid geometry features. You access this interface by selecting the Create button in the Frames expandable area.

Examples

Using the Common Gear Block

Models a pair of gears with parallel axes. The assembly contains the two gears and all constraints required for the gear set. The assembly can be configured to model an external or internal gear set by adjusting parameters in the mask.

Open Model

Full Vehicle on Four Post Testrig

Models a passenger vehicle on a four-post testrig. The posts move up and down to replicate the vertical movement of the wheels as it travels along a road. The simulation results and animation show the response of the vehicle body and suspension as it is subjected to the motions from the testrig. The roll and pitch of the vehicle body can be observed, and by varying the inputs wheel hop frequencies can be determined. The vehicle model can be configured to use different suspension types for the front suspension with different linkage combinations.

Open Model

Limitations

On Mac, the visualization pane runs slow if the generated geometry has a large number of triangles or vertices. To mitigate this issue, you can decrease the number of points in the cross-section.

Ports

Frame

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R — Reference frame
frame

Local reference frame of the solid. This frame is fixed with respect to the solid geometry. Connect this port to a frame entity—port, line, or junction—to resolve the placement of the reference frame in a model. For more information, see Working with Frames.

Geometry

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CH — Convex hull representation
geometry

Convex hull that represents the geometry of the solid. Connect this port to a Spatial Contact Force block to model contacts on the convex hull.

Dependencies

To enable this port, under Geometry, expand Export and select Convex Hull.

Parameters

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Geometry

Revolution: Cross-section — Cross-section coordinates specified on the XZ plane
`[1 1; 1 -1; 2 -1; 2 1] m` (default) | two-column matrix with units of length

Cross-sectional shape specified as an [x,z] coordinate matrix, with each row corresponding to a point on the cross-sectional profile. The coordinates specified must define a closed loop with no self-intersecting segments.

The coordinates must be arranged such that from one point to the next the solid region always lies to the left. The block revolves the cross-sectional shape specified about the reference frame z axis to obtain the revolved solid.

Revolution: Extent of Revolution — Selection of a full or partial revolution
`Full` (default) | `Custom`

Type of revolution sweep to use. Use the default setting of Full to revolve the cross-sectional shape by the maximum 360 degrees. Select Custom to revolve the cross-sectional shape by a lesser angle.

Revolution: Revolution Angle — Sweep angle of a partial revolution
`180` (default) | positive scalar

Angle of the rotational sweep associated with the revolution.

Convex Hull — Generate a convex hull representation of the true geometry
`off` (default) | `on`

Select Convex Hull to generate a convex hull representation of the true geometry. This convex hull can be used for contacts by connecting the Spatial Contact Force block.

Dependencies

To enable this option, select Convex Hull under the Export.

Inertia

Type — Inertia parameterization to use
`Calculate from Geometry` (default) | `Point Mass` | `Custom`

Inertia parameterization to use. Select Point Mass to model a concentrated mass with negligible rotational inertia. Select Custom to model a distributed mass with the specified moments and products of inertia. The default setting, Calculate from Geometry, enables the block to automatically calculate the rotational inertia properties from the solid geometry and specified mass or mass density.

Based on — Parameter to base inertia calculation on
`Density` (default) | `Mass`

Parameter to use in inertia calculation. The block obtains the inertia tensor from the solid geometry and the parameter selected. Use Density if the material properties are known. Use Mass if the total solid mass if known.

Density — Mass per unit volume of material
`1000 kg/m^3` (default)

Mass per unit volume of material. The mass density can take on a positive or negative value. Specify a negative mass density to model the effects of a void or cavity in a solid body.

Mass — Total mass of the solid element
`1 kg` (default) | scalar with units of mass

Total mass to attribute to the solid element. This parameter can be positive or negative. Use a negative value to capture the effect of a void or cavity in a compound body (one comprising multiple solids and inertias), being careful to ensure that the mass of the body is on the whole positive.

Custom: Center of Mass — Center-of-mass coordinates
`[0 0 0] m` (default) | three-element vector with units of length

[x y z] coordinates of the center of mass relative to the block reference frame. The center of mass coincides with the center of gravity in uniform gravitational fields only.

Custom: Moments of Inertia — Diagonal elements of inertia tensor
`[1 1 1] kgm^2` (default) | three-element vector with units of masslength^2

Three-element vector with the [I_xx I_yy I_zz] moments of inertia specified relative to a frame with origin at the center of mass and axes parallel to the block reference frame. The moments of inertia are the diagonal elements of the inertia tensor

$(\begin{matrix} I_{x x} \\ I_{y y} \\ I_{z z} \end{matrix}),$

where:

$I_{x x} = \int_{m} (y^{2} + z^{2}) d m$
$I_{y y} = \int_{m} (x^{2} + z^{2}) d m$
$I_{z z} = \int_{m} (x^{2} + y^{2}) d m$

Custom: Products of Inertia — Off-diagonal elements of inertia tensor
`[0 0 0] kgm^2` (default) | three-element vector with units of masslength^2

Three-element vector with the [I_yz I_zx I_xy] products of inertia specified relative to a frame with origin at the center of mass and axes parallel to the block reference frame. The products of inertia are the off-diagonal elements of the inertia tensor

$(\begin{matrix} I_{x y} & I_{z x} \\ I_{x y} & I_{y z} \\ I_{z x} & I_{y z} \end{matrix}),$

where:

$I_{y z} = - \int_{m} y z d m$
$I_{z x} = - \int_{m} z x d m$
$I_{x y} = - \int_{m} x y d m$

Calculate from Geometry: Derived Values — Display of calculated values of mass properties
button

Display of the calculated values of the solid mass properties—mass, center of mass, moments of inertia, and products of inertia. Click the Update button to calculate and display the mass properties of the solid. Click this button following any changes to the block parameters to ensure that the displayed values are still current.

The center of mass is resolved in the local reference frame of the solid. The moments and products of inertia are each resolved in the inertia frame of resolution—a frame whose axes are parallel to those of the reference frame but whose origin coincides with the solid center of mass.

Dependencies

The option to calculate and display the mass properties is active when the Inertia > Type block parameter is set to Calculate from Geometry.

Graphic

Type — Graphic to use for visualization
`From Geometry` (default) | `Marker` | `None`

Type of the visual representation of the solid, specified as From Geometry, Marker, or None. Set the parameter to From Geometry to show the visual representation of the solid. Set the parameter to Marker to represent the solid as a marker. Set the parameter to None to hide the solid in the model visualization.

Visual Properties — Parameterizations for color and opacity
`Simple` (default) | `Advanced`

Parameterizations for specifying visual properties. Select Simple to specify Diffuse Color and Opacity. Select Advanced to specify more visual properties, such as Specular Color, Ambient Color, Emissive Color, and Shininess.

Dependencies

To enable this parameter, set Type to From Geometry or Marker.

Shape — Shape of marker to represent to the solid
`Sphere` (default) | `Cube` | `Frame`

Shape of the marker by means of which to visualize the solid. The motion of the marker reflects the motion of the solid itself.

Dependencies

To enable this parameter, set Type to Marker.

Size — Width of the marker in pixels
10 `pixels` (default) | scalar

Width of the marker in pixels. This width does not scale with zoom level. Note that the apparent size of the marker depends partly on screen resolution, with higher resolutions packing more pixels per unit length, and therefore producing smaller icons.

Dependencies

To enable this parameter, set Type to Marker.

Color — Color of light due to diffuse reflection
[0.5 0.5 0.5] (default) | 3-by-1 or 1-by-3 vector with values in the range of 0 to 1 | 4-by-1 or 1-by-4 vector with values in the range of 0 to 1

Color of the graphic under direct white light, specified as an [R G B] or [R G B A] vector on a 0–1 scale. An optional fourth element (A) specifies the color opacity on a scale of 0–1. Omitting the opacity element is equivalent to specifying a value of 1.