# Suspension simulation

Question asked by Mark Pugh on Apr 26, 2017
Latest reply on Apr 26, 2017 by Gian Flavio Violi

I'm currently doing my final year dissertation in Mechanical Engineering.

I've created 1/4 of a car suspension system based around a model of a r.c car i found online.

I need to run a simulation of the setup so that i can make adjustments to the damping coefficient and spring rate to see what effect this will have on the time it takes the system to stop oscillating.

I know how to add the spring and damper to the assembly, and i can start a simulation. The first problem is when i add in gravity. The wheel drops to the lowest position allowable. I have set the "bump limits" using a distance mate either side of a center line inside the damper. How can i make the wheel sit in its central position, as if it were resting on a solid ground? Do i need a solid ground to achieve this? I've tried creating one several times, but have been unable to make the wheel and the surface have the correct collision,

If i rectify the first problem, how can i generate the deflection in the wheel needed to represent a collision with a bump/kerb/pot hole? I was initially using the linear motor function in the motion study, however i dont think that will give me any results that are usable. Surely if i make the wheel move up and down using a motor, the deflection plot of the oscillations will just represent the input i specified for the motor?

I know that this is possible, i found a pdf white paper about motion study on the solidworks site, it describes exactly what id like to achieve. However this is only outlining the possibilities so was no help practically. Below is a picture I've screen shotted from the pdf.

I've also attached a drop box link of what i think is my model correctly zipped using pack and go. All of the components are there and the assembly is titled assembly for sim 7. (I've had numerous failed attempts)

I'm literally staring to panic with this. The university support is utterly useless, verging on non existent, and everybody who has claimed to know the in's and out's of Solidworks has been out of their depth immediately trying to run simulations.

Any help or advice would be greatly appreciated. Thanks