Variable Brick Solid

Solid brick with variable dimensions and mass properties

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  • Variable Brick Solid block

Libraries:
Simscape / Multibody / Body Elements / Variable Mass

Description

The Variable Brick Solid block models a solid brick whose dimensions and mass properties can change during simulation. The block uses the scalar equation

m=ρ∗lx∗ly∗lz,

where:

  • m is the mass of the solid brick.

  • ⍴ is the density of the solid brick.

  • lx, ly, and lz are the dimensions of the solid brick along its reference axes.

You can compute any variable by providing the other four variables. If the equation is rearranged and any variable appears in the denominator, ensure that this variable is nonzero to maintain the validity of the equation. Also, when calculating brick dimensions, mass and density must share the same sign.

To model a variable brick solid, select one parameter to compute automatically, then define the remaining parameters by using either constant values or time-varying physical signals. The reference frame is located at the center of the xy cross-section.

Variable brick solid with increasing length in z-dimension

Ports

Frame

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Reference frame of the variable brick solid, fixed at the center of the xy cross-section.

Input

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Length of the variable brick solid along the x-axis of its reference frame. The value must be nonnegative. In the x-direction, the solid brick expands and contracts symmetrically about the origin.

Parameter Dependencies

To enable this port:

  • Do not set Automatically Compute to X Length.

  • Under Geometry and Inertia, set X Length to Provided by Input.

Length of the variable brick solid along the y-axis of its reference frame. The value must be nonnegative. In the y-direction, the solid brick expands and contracts symmetrically about the origin.

Parameter Dependencies

To enable this port:

  • Do not set Automatically Compute to Y Length.

  • Under Geometry and Inertia, set Y Length to Provided by Input.

Length of the variable brick solid along the z-axis of its reference frame. The value must be nonnegative. The solid brick expands and contracts only in the positive z-direction.

Parameter Dependencies

To enable this port:

  • Do not set Automatically Compute to Z Length.

  • Under Geometry and Inertia, set Z Length to Provided by Input.

Density of the variable brick solid.

Parameter Dependencies

To enable this port:

  • Do not set Automatically Compute to Density.

  • Under Geometry and Inertia, set the Density parameter to Provided by Input.

Mass of the variable brick solid.

Parameter Dependencies

To enable this port:

  • Do not set Automatically Compute to Mass.

  • Under Geometry and Inertia, set the Mass parameter to Provided by Input.

Output

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Length of the variable brick solid along the x-axis of its reference frame.

Parameter Dependencies

To enable this port, under Sensing, select X Length.

Length of the variable brick solid along the y-axis of its reference frame.

Parameter Dependencies

To enable this port, under Sensing, select Y Length.

Length of the variable brick solid along the z-axis of its reference frame.

Parameter Dependencies

To enable this port, under Sensing, select Z Length.

Density of the variable brick solid.

Parameter Dependencies

To enable this port, under Sensing, select Density.

Mass of the variable brick solid.

Parameter Dependencies

To enable this port, under Sensing, select Mass.

Center of mass of the variable brick solid. The signal is a 3-by-1 vector that contains the Cartesian coordinates of the center of mass, expressed in the reference frame of the variable brick solid.

Parameter Dependencies

To enable this port, under Sensing, select Center of Mass.

Inertia matrix of the variable brick solid. The signal is a 3-by-3 matrix, expressed in the reference frame of the variable brick solid.

Parameter Dependencies

To enable this port, under Sensing, select Inertia Matrix.

Parameters

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Geometry and Inertia

Specify which variable of the brick solid that the block calculates based on the values of the other variables.

Length of the variable brick solid along the x-axis of its reference frame. To use a fixed value, select Constant. To specify a time-varying value via a physical signal, select Provided by Input.

Parameter Dependencies

To enable this parameter, do not set Automatically Compute to X Length.

Length of the variable brick solid along the x-axis of its reference frame. The length remains constant throughout the simulation.

Parameter Dependencies

To enable this parameter:

  • Do not set Automatically Compute to X Length.

  • Under Geometry and Inertia, set X Length to Constant.

Length of the variable brick solid along the y-axis of its reference frame. To use a fixed value, select Constant. To specify a time-varying value via a physical signal, select Provided by Input.

Parameter Dependencies

To enable this parameter, do not set Automatically Compute to Y Length.

Length of the variable brick solid along the y-axis of its reference frame. The length remains constant throughout the simulation.

Parameter Dependencies

To enable this parameter:

  • Do not set Automatically Compute to Y Length.

  • Under Geometry and Inertia, set Y Length to Constant.

Length of the variable brick solid along the z-axis of its reference frame. To use a fixed value, select Constant. To specify a time-varying value via a physical signal, select Provided by Input.

Parameter Dependencies

To enable this parameter, do not set Automatically Compute to Z Length.

Length of the variable brick solid along the z-axis of its reference frame. The length remains constant throughout the simulation.

Parameter Dependencies

To enable this parameter:

  • Do not set Automatically Compute to Z Length.

  • Under Geometry and Inertia, set Z Length to Constant.

Mass per unit volume of the material. To use a fixed value, select Constant. To specify a time-varying value via a physical signal, select Provided by Input.

Parameter Dependencies

To enable this parameter, do not set Automatically Compute to Density.

Density of the variable brick solid. The value remains constant throughout the simulation. To model the effect of a void or cavity in a compound body, use a negative value. The overall mass of the compound body must remain positive.

Parameter Dependencies

To enable this parameter:

  • Do not set Automatically Compute to Density.

  • Under Geometry and Inertia, set Density to Constant.

Mass of the variable brick solid. To use a fixed value, select Constant. To specify a time-varying value via a physical signal, select Provided by Input.

Parameter Dependencies

To enable this parameter, do not set Automatically Compute to Mass.

Mass of the variable brick solid. The value remains constant throughout the simulation. To model the effect of a void or cavity in a compound body, use a negative value. The overall mass of the compound body must remain positive.

Parameter Dependencies

To enable this parameter:

  • Do not set Automatically Compute to Mass.

  • Under Geometry and Inertia, set Mass to Constant.

Graphic

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.

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 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.

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 of the light due to diffuse reflection, specified as an [R,G,B] or [R,G,B,A] vector with values in the range of 0 to 1. The vector can be a row or column vector. The optional fourth element specifies the color opacity. Omitting the opacity element is equivalent to specifying a value of 1.

The diffuse color reflects the main color of the rendered solid and provides shading that gives the rendered object a three-dimensional appearance.

Dependencies

To enable this parameter, set:

  1. Type to From Geometry or Marker.

  2. Visual Properties to Advanced.

Graphic opacity, specified as a scalar in the range of 0 to 1. A scalar of 0 corresponds to completely transparent, and a scalar of 1 corresponds to completely opaque.

Dependencies

To enable this parameter, set:

  1. Type to From Geometry or Marker.

  2. Visual Properties to Simple.

Color of the light due to specular reflection, specified as an [R,G,B] or [R,G,B,A] vector with values in the range of 0 to 1. The vector can be a row or column vector. The optional fourth element specifies the color opacity. Omitting the opacity element is equivalent to specifying a value of 1. This parameter changes the color of the specular highlight, which is the bright spot on the rendered solid due to the reflection of the light from the light source.

Dependencies

To enable this parameter, set:

  1. Type to From Geometry or Marker.

  2. Visual Properties to Advanced.

Color of the ambient light, specified as an [R,G,B] or [R,G,B,A] vector with values in the range of 0 to 1. The vector can be a row or column vector. The optional fourth element specifies the color opacity. Omitting the opacity element is equivalent to specifying a value of 1.

Ambient light refers to a general level of illumination that does not come directly from a light source. The Ambient light consists of light that has been reflected and re-reflected so many times that it is no longer coming from any particular direction. You can adjust this parameter to change the shadow color of the rendered solid.

Dependencies

To enable this parameter, set:

  1. Type to From Geometry or Marker.

  2. Visual Properties to Advanced.

Color due to self illumination, specified as an [R,G,B] or [R,G,B,A] vector in the range of 0 to 1. The vector can be a row or column vector. The optional fourth element specifies the color opacity. Omitting the opacity element is equivalent to specifying a value of 1.

The emission color is color that does not come from any external source, and therefore seems to be emitted by the solid itself. When a solid has an emissive color, the solid can be seen even if there is no external light source.

Dependencies

To enable this parameter, set:

  1. Type to From Geometry or Marker.

  2. Visual Properties to Advanced.

Sharpness of specular light reflections, specified as a scalar number on a 0–128 scale. Increase the shininess value for smaller but sharper highlights. Decrease the value for larger but smoother highlights.

Dependencies

To enable this parameter, set:

  1. Type to From Geometry or Marker.

  2. Visual Properties to Advanced.

Extended Capabilities

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C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

Version History

Introduced in R2017b

See Also

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