Recent content by marvincwl

If this is fastened in a random vibration machine and the fasteners used are socket head cap screws? The fasteners will only create a compressive force at the threads and at the contact of the cap and the block? so the g-force from the vibration is not transferred??!

Homework Statement It's not exactly a homework question, just want to see if i have the right concept in drawing free body diagrams See attached Picture. In case 1, the object is fastened on plane x-z and the rectangular block is fastened to the T-block in y-z plane. Will the force be...

thanks a lot everyone

Thanks potatoecannon.

Hi Jobrag, This is what I meant. I do not get why it must be the second case (lower drawing). Why can't both mating parts (top&bottom) be threaded?

I'm unsure as to why only one of two mating parts are threaded? The top part is usually a clearance hole and the thread is only applied to the bottom part. Why is this so?

Your first statement gave me clues. I went to look at the drawings for the vibration machine and it has only ONE accelerometer measuring a single axis. It is placed close to the specimen. However, upon reading some literature (attached file), the Grms and G-force values are correlated by a...

use Darcy weisbach eq http://en.wikipedia.org/wiki/Darcy%E2%80%93Weisbach_equation calculate the reynolds no. and find out the friction factor using the moody diagram, unless u can assume whether its laminar/turbulent/ if friction factor is already given

what is the full question, it is usually influenced by temperature at higher altitudes

can u clarify what you mean by "bending"

just plug in the limits to the substitutition. but usually you do not substitute a sec function, usually you would substitute a simpler function. gd luck.

You are both right. But thanks for the detail in explanation for the part on RMS @Vadar2012. I'm comparing because I want to ensure that the level of excitation at the component on the test specimen is really experiencing the desired magnitude of vibration that I've set on the vibration...

@vadar2012 - I want to reconcile the graphs as I want to confirm the magnitude of vibration applied by the vibration machine to the test specimen. ( however by using an accelerometer, it gives g-force while machine gives Grms) - The vibration machine is a random vibration machine, as such does...

Yes the accelerometer is of a larger value as I'm referring to the peak values and Grms is derived from the integral of the PSD plot. But how do i convert the g-force values of the accelerometer such that i can compare it with the Grms value the vibration machine gives? (both the...

m(a-g)+T= 2mg-T ma= 3mg-2T a=(3g-2(T/m)) this is the acceleration of the mass?