All Information You need to Set up, Run and Analyze Your Multibody Dynamics Simulation – Complemented with some Usefull Tips from principia MBS

In our former blog articles, we discussed Motion Analysis and some key facts about this topic. Now, in this blog we want to combine this theoretical knowledge with some practical stuff. Therefore, we will introduce you to the basic functions of our software principia MBS and how you install and use it in your Onshape environment.   

Who and What is principia MBS – A Short Recap on Motion Analysis

First, let’s start with a short introduction to our company principia MBS GmbH. The company was founded in March 2023 as a solution provider for design validation tools, that can be integrated in established CAE platforms. Our five founders combine expertise in the fields of numerical solvers for modelling dynamical systems and algorithms for dynamical analysis, UI and UX design, and web development.  

With our first product principia MBS, the first truely cloud-native software, we provide users with a powerful tool for modelling, simulating and analyzing multibody systems. As a virtual test bench, it closes the gap between design and design validation that currently exists in all engineering cloud solutions.  

What is Multibody Simulation?

Talking about Multibody Simulation (MBS) – also called Multibody Dynamics (MBD), Multibody Dynamics Simulation, or Motion Analysis – we talk about the analysis of multibody systems and their movements. With multibody systems we thereby mean systems consisting of several parts that are interconnected and moveable. With appropriate software you can let them move virtually long before you hold them in hands. You can get information about acting forces and gain insights into the system’s behavior. You can evaluate performance, identify issues, and optimize components and parameters. To name just a few. 

So, what can we now do with MBD? Typical key applications are functionality checking by virtual testing and analyzing mechanical systems. This results in reduced risk and cost associated to physical prototyping. Further, scaling of parts and machine elements by providing insights into component performance under different conditions. Another application is load generation by generating loads on parts and investigating their effects on mechanical systems. You will find MBD applied in industries like automotive, robotics, agricultural technology, energy, as well as logistics and biomechanics. You see, quite a broad range of applications. 

Now you have a glimpse about what Motion Analysis and principia MBS are. So let’s continue with the actual usage of the tool.  

How to Use principia MBS in Onshape

Before we start with explaning how principia MBS is used, in this case, how it’s used in Onshape, here’s a short description of the tool itself. 

A Brief Introduction to the Software

principia MBS is the first true cloud-native solution for modelling, simulating and analyzing multibody systems. With its highly efficient mathematical solvers and algorithms it can calculate highly complex multibody simulations in a short time. This means tremendous time savings for companies developing mechanical machinery or systems. The software further helps to decrease physical prototyping as it delivers virtual results of the system’s behavior. 

How to Use principia MBS in PTC Onshape?

Before you can start your first Multibody Dynamics Simulation in principia MBS, you need to get and install it. Just go to the Onshape App Store and subscribe to our 30-day free trial version of principia MBS and do your first simulation steps for free. For your further professional usage you can contact our Sales Specialist at any time. As soon as you have added principia MBS to your Onshape environment, you can start right away. By clicking on the principia icon at the bottom of the taskbar you can switch directly to principia. Now you can bring your CAD models to life virtually. 

principia MBS integrated in Onshape with your first simple geometry ready for simulating

So, now you can either create a new geometry or design, or you choose existing geometries out of your Onshape library and start setting up your simulation. First, you have to build up your multibody system by connecting your geometries. Additionally, principia MBS not only takes over the geometry, but also settings you have made during the design. These can be either material parameters or the kinematics by interpretation of mates and mate connectors.   

Key Areas in principia MBS concisely Explained

Now that you have imported your geometries with the correct names and configured all connectors in your assembly, it is time to set up your simulation run. The software guides you through defining all necessary parameters within its modeling interface. This consists of five sections: Bodies, Constraints, Forces, Sensors, and Settings

In the Bodies section, you will find a summary of all bodies imported from Onshape. Here you have the option to make modifications like adjusting inertia properties. The Constraints section summarizes all mate features imported from Onshape. It allows you to modify locked degrees of freedom as needed. 

Forces, Sensors, and Settings are specific to principia MBS. In the Forces section, you can define external forces acting on your system. The Sensors section allows you to set up sensors for data collection during simulation. Finally, the Settings section provides additional configuration options tailored to principia MBS. 

Once all parameters are configured to your specifications, you can initiate the simulation by clicking the prominent blue Start Simulation button within the modeling interface. The button changes to yellow and displays Processing, indicating that principia MBS is now computing your simulation.


principia MBS user interface in PTC Onshape with all parameters to set and simulation running

Now, you are only a few seconds away from your results to be listed in the principia Simulations tab. There you can watch your simulation run and see your results and all the parameters you have set. If your results are not as expected, you can check whether you have set some parameters incorrectly or not at all. You can then refine your input and start the next simulation.   

Simulation results in principia MBS shown in a graph and below the documentation with all simulation inputs is listed

Getting Started with Motion Analysis and principia MBS

Now that you have familiarized yourself with Motion Analysis and tried out principia MBS, it is time to carry out your first simulation. If you haven’t already, grab the 30-day free trial of principia MBS to start. It’s easy to find in the Onshape App store. Just search for principia MBS, and you’re ready to roll. Once it’s installed, you’ll see it right there in your Onshape CAD software. 

Even though you are sticking with Onshape, there might be some new stuff to figure out in principia MBS. But do not worry – practice makes perfect! Start with the multibody system we provide, watch the video tutorial, and give it a shot. You might surprise yourself! 

The content of this blog article is also available as a video, in a slightly longer and detailed version, in our webinars. So, feel free to watch, if you need some additional information. 

If you have any questions not yet answered, please leave us a message. We are always here for you and pleased to help you with our expertise.