Hello, I am Clément Ganier with Siemens PLM Software.
Today, I'm going to present the Mount Design Assistant.
In automotive vehicles, the engine vibrations must be isolated
as much as possible, in order to ensure best comfort for the driver.
This is the goal of engine mounts, which are rubber or hydraulic isolators,
located between the chassis and the engine block.
The engine mounts properties, so positions,
orientation, stiffness and damping, play an important role in vehicle NVH,
noise, vibration and harshness, and it must be designed very carefully.
The Mount Design Assistant in LMS Imagine.Lab Amesim,
is a graphical user interface on top of the engine block submodels,
dedicated to the optimization of engine mounts properties.
Let's take a very simple model of a 3D engine block, connected to
a fix ground through three engine mounts.
Let's launch engine Mount Design Assistant.
We have a 3D view of the system here.
Suppose that first we have three 3D rigid bodies,
that can move in all the six degrees of freedom.
So, the longitudinal direction, lateral direction, vertical direction and all the
three rotations around those axes.
If we apply a torque to these three rigid bodies, on a defined direction,
then it will rotate around an axis, which is called the torque roll axis, TRA.
We can see the torque roll axis by clicking on this check box here,
and it will appear in black, in the drawing.
Here, these are the coordinates of the torque roll axis.
Now, suppose that we connect these 3D engine blocks to the chassis through the mounts.
The engine block will not have a perfect rotation around the torque roll axis,
but it will have a complex couple motion in all the directions.
This is what we call mode coupling. Mode coupling must be avoided
because il leads to poor comfort feeling for the driver.
That's why we can use the Mount Design Assistant and a metric, that we call
modal kinetic energy distribution, here.
So this is basically 6 by 6 matrix, with all the natural frequencies of the
system in line, and all the six degrees of freedom in column.
For given natural frequency, for example 32 hertz here, we see that the model energy
is splited between X and Z directions.
Its means that these modes and these degrees of freedom, x and z, are coupled together.
We can check with the model, if we launch an animation with these parameters,
and open the animation, here, we can see that
the engine block has a complex couple motion, with high amplitudes.
So the goal of the Mount Design Assistant is to find the optimal
properties, so positions, orientations and stiffnesses,
in order to decouple the engine block modes.
So now, let's click on this button, in order to compute the optimal properties.
So we have here the values of the positions, orientations and stiffnesses.
We can recheck that the model kinetic energy distribution
is now almost perfect diagonal matrix,
and each natural frequency is linked with a single degree of freedom.
Ok, so now let's apply this optimal values to the model,
and relaunch a simulation.
If we check the animation, we can see that, now,
the engine block has a perfect rolling motion
with small amplitude around the torque roll axis.
As a conclusion, the Mount Design Assistant allows you to optimize the mounts parameters,
in order to decouple the engine block modes, and in order to improve vehicle NVH.
Thank you for watching, for more information please visit our website.