Mini Guide: SiemensNX MCD - Key Simulation Concepts Explained

This quick-reference guide explains the essential elements you’ll use when building simulations in Siemens NX Mechatronics Concept Designer (MCD). It’s ideal for beginners or as a refresher before modeling a Digital Twin.

Rigid Body

A rigid body is any component that should physically interact in the simulation. Once an element is marked as a rigid body, it can interact with other objects, move, and be constrained by joints or forces.

• Example: A piston, conveyor belt plate, or workpiece must be set as a rigid body to take part in the physics simulation.

• Tip: In SiemensNX MCD, use Rigid Body Colour to have a preview of components that have rigid bodies created

Collision Body

Collision bodies define the shapes that will participate in collision detection. These are derived from faces or bodies and are essential for sensors or realistic interaction.

• Example: A workpiece falling into a slide should bounce or stop due to a collision with a body.

Collision Material

Collision materials define how objects interact when they collide, including bounce, friction, and dampening effects. They can be applied to collision bodies to simulate different material behaviours.

• Example: A rubber stopper versus a metal slide will react differently depending on the material assigned to them.

Transport Surface

A transport surface moves parts along its direction. It requires a surface and a velocity vector to guide the object’s motion. Commonly used for conveyor belts.

• Tip: Ensure the velocity vector is aligned parallel to the surface.

• Example: A conveyor that transports workpieces from one station to another.

Fixed Joint

Used to permanently lock two rigid bodies together. No movement is allowed.

• Example: A sensor holder mounted to a frame.

Sliding Joint

Allows linear movement between components. Limits can be added to ensure it will only perform movement to X millimetres.

• Example: A piston sliding in a cylinder.

Hinge Joint

Allows rotational motion around one axis. Often used with rotary actuators.

• Example: A gripper arm or rotating base.

Position Control

Enables control over joint movement via programmable logic controller (PLC) signals. Define named positions (e.g., ON, OFF) and send input signals to move the mechanism.

• Example: Moving a suction cup from UP to DOWN.

Collision Sensors

These detect when a specific collision body is touched. You typically define them as lines, planes, or faces. Their signal state (TRUE/FALSE) changes during simulation.

• Example: A sensor that detects a workpiece has arrived.

Signals

Signals are the digital link between Siemens NX and TIA Portal. Each actuator or sensor can have associated signals (inputs or outputs).

• Example: PICK_Suction_ON signal to engage the suction cup.

Signal Mapping

This is the process of linking NX signals to PLC Tags from TIA Portal. If names match exactly, you can use automapping.

• Tip: Keep naming consistent for easy integration.

Object Source

Defines where new parts (workpieces) are spawned in the simulation. Time intervals and offsets can be adjusted to meet requirements.

• Example: A magazine feeding parts onto the conveyor.

Object Sink

Represents where parts leave the system. Often used to simulate sorting or removal.

• Example: Sinks at the end of slides to collect sorted workpieces.

Prevent Collision

A sensor option that disables physical interaction. This allows a sensor to detect without disturbing the part’s motion.

• Example: Used for colour sensors.

Gripper / Suction Cup

Suction cups simulate the process of picking and releasing objects. You control them using signals and collision logic.

• Standard Setup: Attach the suction cup to a slide or rotary joint. Add two signals: one for suction ON and one for OFF (Grip, Release).