Load cases to analyse a bus-chassis part?

[pedrorb]

Hi,

I have to evaluate via FEM a chassis part from a bus: the last transverse beam, which supports part of the motor weight. I am just wondering about the load cases I must consider. If the beam is 3-DOF restricted in its end, and the motor is simulated as a point-mass over the beam linked to it, how much should its weight be? 2g, 3g? If there is a braking, should I consider more than 1g?
I just don't want my motor to fall onto the street in any case....

Thak you everyone in advanced

PedroRB

 

[GregLocock]

That's a good question and not an easy one to answer. Such a simple model is no good for fatigue life prediction, so the simple answer is just what is the rest of the structure designed to? More usefully, I don't remember seeing more than 1g of dynamic load on a body part, so 2g vertically (ie 1g weight plus 1g dynamic), in total, would be a good start. 1g in each of the horizontal planes is also reasonable.

I emphasise that this is very crude, and not really of much use for anything more sophisticatd than a back-of-the-envelope-calculation in the real world. Cheers

Greg Locock