Model files are composed of many different parts, or entities. MotionView allows you to change the display attributes of each entity in a graphic. Visual properties such as shading, color, and
mesh lines can be assigned using the Graphic Entity Attributes panel.
The System/Assembly panel allows you to add new systems and assemblies to your model, modify attachments, and set
initial conditions and options for systems and assemblies.
The Command Sets panel allows you to create command sets for the solver-command file. The command sets for a model are
order dependent, since they define the contents of the solver command file.
Use the Deformable Surfaces tool to create and edit deformable surfaces. These entities can change shape during the simulation
and can be used with advanced joints and contacts.
Use the Advanced Joints tool to create and edit a set of special constraints called higher pair joints. Typically, these are constraints
that involve a curve or surface on at least one of the two bodies.
A point to curve joint consists of a fixed point on one body sliding on a curve that is fixed on a second body. The
point is not allowed to lift off the curve. The curve on the second body should be a 3D curve and needs to be specified
using a MotionView curve (which is a reference entity).
The curve to curve constraint consists of a 3D curve fixed on one body rolling and sliding on a 3D curve fixed on
a second body. The curves are required to have a unique point of contact and a common tangent at that point of contact.
The curve-to-curve constraint is useful for modeling cams where the point of contact between two parts changes during
the motion of the system. The curves always maintain contact, however, even when the physics of the model
might dictate that one curve lift off the other.
A point to surface joint constrains a fixed point on a body to slide along a surface. The point to surface joint provides
five degrees of freedom: three rotational at the instantaneous point of contact and two translational DOF.
The surface to surface constraint consists of a surface on one body rolling and sliding on the surface of a second
body. Each of the surfaces are required to have a unique contact point. The surface to surface joint constrains the
two surfaces as follows: the surfaces have exactly one contact point, and the normal at the contact point for each
is anti-parallel.
The point to deformable curve joint constrains a fixed point on a body to slide along a curve that passes through
the origins of a specified set of markers. These markers may belong to different bodies. As the markers move in space,
the curve is calculated at every time step using CUBIC spline interpolation through the marker origins. Hence, the
curve deforms as the markers move about.
The point to deformable surface joint constrains a fixed point on a body to slide along a surface that passes through
the origins of a specified set of markers. These markers may belong to different bodies. As the markers move in space,
the surface is calculated at every time step using CUBIC spline interpolation through the marker origins. Hence, the
surface deforms as the markers move about.
Constraint mates offer higher pair constraints in the form of distance, coincidence and tangency between two analytical
geometries. The geometries could be point, line, sphere, cylinder, cone or a plane. The geometry is defined analytically
using bodies and points.
Use the Fields tool to create a compliant connection between two bodies where stiffness or damping in one direction can be a function
of displacement in another direction
Use the Variables tool to create solver variables that can be used to create an algebraic expression of state variables, as well as
other solver variables. This can then be referenced in function expressions throughout the solver input file.
Use the Arrays tool to create solver arrays and set solver array data. Solver array types include X array, Y array, U array, IC
array, Plant Input array, and Plant Output array.
Use the Strings tool to create a solver string and set solver string data. A solver string provides a string that can be accessed
within the model, for example, to pass into a user subroutine.
Use the Diff Equations tool to set solver differential equations. These equations can be used to add additional states to the mechanical
system being modeled.
Use the Advanced Joints tool to create and edit a set of special constraints called higher pair joints. Typically, these are constraints
that involve a curve or surface on at least one of the two bodies.
Point to Curve (PTCV)
A point to curve joint consists of a fixed point on one body sliding on a curve that is fixed on a second body. The point is not allowed to lift off the curve. The curve on the second body should be a 3D curve and needs to be specified using a MotionView curve (which is a reference entity).
Curve to Curve (CVCV)
The curve to curve constraint consists of a 3D curve fixed on one body rolling and sliding on a 3D curve fixed on a second body. The curves are required to have a unique point of contact and a common tangent at that point of contact. The curve-to-curve constraint is useful for modeling cams where the point of contact between two parts changes during the motion of the system. The curves always maintain contact, however, even when the physics of the model might dictate that one curve lift off the other.
Point to Surface (PTSF)
A point to surface joint constrains a fixed point on a body to slide along a surface. The point to surface joint provides five degrees of freedom: three rotational at the instantaneous point of contact and two translational DOF.
Curve to Surface (CVSF)
The curve to surface joint provides five degrees of freedom: three rotational at the instantaneous point of contact and two translational DOF.
Surface to Surface (SFSF)
The surface to surface constraint consists of a surface on one body rolling and sliding on the surface of a second body. Each of the surfaces are required to have a unique contact point. The surface to surface joint constrains the two surfaces as follows: the surfaces have exactly one contact point, and the normal at the contact point for each is anti-parallel.
Point to Deformable Curve (PTDCV)
The point to deformable curve joint constrains a fixed point on a body to slide along a curve that passes through the origins of a specified set of markers. These markers may belong to different bodies. As the markers move in space, the curve is calculated at every time step using CUBIC spline interpolation through the marker origins. Hence, the curve deforms as the markers move about.
Point to Deformable Surface (PTDSF)
The point to deformable surface joint constrains a fixed point on a body to slide along a surface that passes through the origins of a specified set of markers. These markers may belong to different bodies. As the markers move in space, the surface is calculated at every time step using CUBIC spline interpolation through the marker origins. Hence, the surface deforms as the markers move about.
Constraint Mates
Constraint mates offer higher pair constraints in the form of distance, coincidence and tangency between two analytical geometries. The geometries could be point, line, sphere, cylinder, cone or a plane. The geometry is defined analytically using bodies and points.