SimSolid Finite Element Equivalents

Recommend equivalents in SimSolid relative to other finite element analysis entities.

Table 1.
SimSolid entity FE equivalent Use cases Key considerations
Connections
General connector RBE2 Used for stiff connections where relative motion is undesirable Be mindful of over-constraining, if applied broadly to large areas, as it can locally stiffen the model.
Bushing RBE2 + CBUSH Flexible connections with defined stiffness in translational and/or rotational directions

This is useful for simulating rubber mounts or flexible bearings where some deformation is expected.

 Requires input of translational and/or rotational stiffness values

Incorrect stiffness values can significantly affect results.
Remote mass -rigid RBE2 + CONM2 Represents a concentrated mass at a specific point (ideally at a COG of selected faces/spots) rigidly connected to selected faces/spots

This is useful for modeling components whose detailed geometry is not required but whose mass contribution is important.

 Ensure the mass is placed at the correct centroid if precise inertia effects are critical
Remote mass - Flexible RBE3* + CONM2 This option allows the connected faces/spots to deform independently while still associating the mass and inertia to them.

*The representation is closer to RBE3, but it introduces artificial local stiffening to the connected region.

 Ensure the mass and inertia values are accurate and the chosen connection entities properly reflect the real-world interface
Distributed Mass NSM (Non-structural mass) Applies a mass per unit area or mass across selected faces

This is useful for modeling coatings, insulation, or additional non-structural weight distributed over a surface.

 The mass is distributed evenly and does not contribute to stiffness.

Ensure correct units for mass per selected area
Pins - Rotating RBE2 + JOINTG-HINGE Simulates a pin joint allowing rotation about a defined axis while restraining translation

This is ideal for hinges, door mechanisms, or pivots.

 Requires selection of cylindrical faces which must be concave
Pins-Bonded RBE2 Models a pin that is rigidly fixed to the surrounding parts, preventing any relative motion like a welded or press-fit pin

This can be an alternative to a general connector for cylindrical interfaces where no relative motion is expected.
Pins-Sliding RBE2 + JOINTG-CYLINDRI Represents a pin that can slide along its axis while allowing rotation about it but restricting radial motion

This is useful for components like linear bearings or telescopic mechanisms.
Shock Absorber CBUSH, CELAS1, CELAS2 Models a damping and/or spring element between two spots or between a spot and ground (origin)

Captures energy dissipation (damping) and elastic restoration (spring)

 Primarily used for dynamic analyses and requires damping and/or stiffness
Rod CELAS1,CELAS2 Simulates a simple axial spring element

This is useful for modeling slender members that only carry axial loads (tension-only/compression-only) without bending.

 Requires axial stiffness definition
Cable CGAP Configured for tension-only behavior

For example, a pre-tensioned tie rod that's always under tension.
Rivet RBE2 Virtual rivets act like perfectly rigid nail-like structures between connected parts Must contain coaxial and/or blind holes, when modeling automatic rivets

A face can be picked on the geometry while modeling rivets manually.
Joints
Ball RBE2 + JOINTG-BALL Allows full spherical rotation about a point while restraining all translational degrees of freedom at the joint center

This is useful for modeling spherical bearings or universal joints where free angular motion in all directions is desired.

 NA
Hinge RBE2 + JOINTG-HINGE Allows rotation about a single axis while restraining translation

Similar to "Pins - Rotating"

This is used for door hinges, pivots, or any single-axis rotational mechanism.
Cylindrical RBE2 + JOINTG-CYLINDRI Allows translation and rotation about a single axis while restraining radial motion

Similar to "Pins - Sliding"

This is ideal for linear bearings, shafts in sleeves, or other mechanisms requiring both axial and rotational freedom.
Linear guide RBE2 + JOINTG-TRANSLAT Allows translation along a single axis while restraining all other translational and rotational degrees of freedom

This is perfect for linear slides, rails, or any component designed for purely linear motion.
Universal RBE2 + JOINTG-UNIVERSA Allows rotation about two orthogonal axes

This is often used in drive shafts to accommodate misalignment. More complex joint type allowing two rotational degrees of freedom.

 Define two axes of rotation
Table 2.
SimSolid entity FE equivalent Use cases Key considerations
Boundary conditions
Remote load on faces and spots Loads on RBE3* Applies a force or moment from a remote point, distributing it to selected faces or spots.

*The representation is closer to RBE3, but it introduces artificial local stiffening to the connected region.

 This is ideal for applying loads from inaccessible points or when the load source is external to the model.
Remote load on General connector Loads on RBE2 Applies a force or moment through a General Connector (RBE2)

This means the load is applied rigidly from the remote point.

 Use this when you want to apply a load that originates from a rigid attachment point. It can cause local stiffening if the RBE2 connects to a large deformable area.
Remote displacement Enforced displacement on RBE2 Applies a prescribed displacement or rotation from a remote point to selected faces or spots

The RBE2 ensures the displacement is applied rigidly.

 This is useful for simulating specific deflections, prescribed movements, or testing component stiffness under defined displacements.

Additional Guidelines

Directional constraints
  1. Use bushings
    • Use bushings to connect two parts or a ground bushing
    • Set all directional stiffness to either rigid or free (zero)
    Note: Always ensure your stiffness values are in the correct units (for example, N/mm, Nm/rad) and accurately reflect the physical properties of the bushing. Incorrect stiffness can lead to inaccurate results.
  2. Use enforced displacement
    • Set displacement to 0 to constrain all displacement in specific direction(s) on faces