Recent content by jprecinos

Hi Gyao. I am reading all the threads in your post and this is what I understand: 1. You have a machine that weights 4.5 Tons. 2. The machine is sitting on 4 shock absorbers. 3. You are trying to calculate how many G's your machine will be subject to during shipping. Is this correct...

yes CAD and FEA is my plan B. But I was hoping that there would be an experimental way to find a solution ... Like those little intertia apparatus they have at the physics labs. An experiment along those lines I was hoping :)

Well the purpose of most simulators is to give you a plattform to recreate dynamics of a variety of vehicles during different scenarios. They do have some starting imput parameters but they won't have real properties on all vehicles out there. I do have access to some engineering databases and...

Agreed! If you are trying to determine if two impact scenarios are equivalent or "similar" like the original post thread, then you need the momentum analysis also. Total energy only gives you one side of the picture. I can bring my car from 60mph to zero at the stop sign….the big difference...

Yes you are missing the ΔT factor that the Momentum Analysis gives you. Both scenarios are pretty bad for the drivers, no doubt. But they won’t necessarily have the same deceleration rates during impact.

I am not a physics major but I can tell you there is a strong conceptual difference between PHY I and PHY II. In my case they each tickled a different part of the brain. The first one is very easy to grasp conceptually because you can connect it to everyday things like how is that building...

Inertial paramaters of a dynamic object: 1. CG location - easy to get. no problem 2. Moments of inertia: Yaw, Pitch, Roll how to calculate the moments experimentally? Yes, most simulators model vehicle dynamics as a spring, damper system, some use a more complexe model than others (with...

I have been playing with several vehicle dynamics simulators for a while now, and many of them require vehicle inertial properties to create realistic simulations. There is very limited published data out there so I was wondering how could one calculate these properties experimentally...

The short answer is no. The 120mph collision is harder. The common sense reason is because a wall barrier has infinite mass and infinite stiffness. For the explanation you can take two approaches: conservation of momentum or conservation of energy. But you have to be careful how you define the...

thanks for the quick replies. So one last question to clear my mind of any doubts :) Say a person is watching the all scenario at the bottom of the cliff and from his reference he can calculate the deceleration of the vehicle after impact. The value that he will calculate in the global system...

I am a bit confused about what accelerometers actually measure and hopefully somebody can help me resolve the following scenario: Say we have a vehicle with mass m, fixed CG location and subject to gravity. The vehicle is traveling at constant speed in the X direction heading to a cliff...