I recently took up a project where I had to quickly get up to speed on what Dynamic Simulation in Inventor was so I decided to do a quick FAQ on what think people would ask when confronted with this situation.

Where do I find Dynamic Simulation?

You will find it under the Environments tab on the left hand side.

Dynamic Simulation

So what is Dynamic Simulation?

The definition in the Autodesk Help files:

“With the dynamic simulation or the assembly environment, the intent is to build a functional mechanism. Dynamic simulation adds to that functional mechanism the dynamic, real-world influences of various kinds of loads to create a true kinematic chain.”

Is there a difference between the Assembly Environment and the Dynamic Simulation Environment?

Yes there is. The first main difference between the assembly environment (AE) and the dynamic simulation environment (DS) is the degrees of freedom. In AE you start with 6 degrees of freedom (DOF) and in DS you start off with 0 DOF.

What does this mean (0 DOF vs 6 DOF)?

6 DOF – you are able to move the component freely in the X,Y and Z directions. You are also able to rotate the component around the X,Y and Z axis.

0 DOF – you are not able to move or rotate the component at all.

In DS you have to then add DOF to your model. Essentially all your components are grounded and you will tell your parts and assemblies what to do. Do they move along the X,Y or Z axis or does it rotate around the X,Y and Z axis.

I have constrained my model in the Assembly Environment and it performs as it should. If Dynamic Simulation essentially grounds the components, then am I losing all the work I have done previously?

No. When you enter the dynamic simulation environment, you have the option to convert all the assembly constraints automatically to joints.   If you do not have the automatically convert constraints to joints setting on, then you can use the convert constraints command. You essentially select the 2 components that are constrained together and Inventor will convert it to the joint that looks like the most appropriate according to the constraints that are applied between the 2 components.

What is the difference between constraints and joints?

A constraint is used in the assembly to position parts in an assembly or to review motion.

A joint is a combination of contraints that allows you to review motion with the addition of properties such as friction, damping and stiffness.

Constraints just take the geometry into consideration and not real world properties like joints do.