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Gauranga
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Guys i need a little help in finding the moment of inertia of a part of a machine which looks like the part of a torus as the arc of a circle.Can somebody help me out with it please?
Gauranga said:Guys i need a little help in finding the moment of inertia of a part of a machine which looks like the part of a torus as the arc of a circle.Can somebody help me out with it please?
Gauranga said:I am an engineer doing and i know the basic equation but the problem is with the part.Basically it is an arm of an instrument which moves and i have to calculate the moment of inertia of it . But the form of it is a little complex. It is a hollow section of solid steel which is similar to a section of a torus.I tried to find formulas of moment of inertia for different structure but the one i need like a 3d hollow arc could not be found.So it will be great if u can help me in that. Ok may be it could be described if u cut the one third of a torus and want to find the moment of inertia of it.Where the arc length is given.the torus diameter is given.The radius of the torus from the center is given to find out the moment of inertia.May be it can be related to some formula?I just can't get it...
gsal said:Yes, somebody could...but while the original reason for this thread might have been understandable and you might be all into it by now...don't give up on the net...can you just google something by yourself? like your last question? come on...
Gauranga said:So i have the uniform accelaration.My rpm is 3.6,acceleration time is half second and my moment of inertia is 71502884 gm cm^2 and in case i have the mass also 75.8 kg.Can somebody help me to use these values to find the torque.
Gauranga said:i think i have found it out by founding angular accn 0.75 rad/sec^2 and by the general formula torque = moment of inertia * angular accelaration.The result is 5.39 kgm^2 rad/sec^2 where i think the rad is not the mater.So the unit seems good.But i was not sure.can someone say that the method was right?
Looks good. And you're correct about the units, as "rad" is considered unitless.Gauranga said:Guys can you please just check the method i applied for torque calculation.
First of all i found the moment of inertia.Then i have the value of a stroke, from where i calculated the rpm.
Then by the formula 2.pi.rpm/60 ,i got the angular acceleration in rad/sec.So i devided the acceleration time by it and got the angular acceleration in rad/sec^2 .
I multiplied that with moment of inertia which was in kg m^2 and got a value in kg.m^2rad/ sec^2.
Where i think rad has no play.so the resulting unit will be Nm which is the right unit for torque.
Can somebody just have a look on the method and say me if i am right?
The moment of inertia for a machine is a measure of its resistance to changes in rotational velocity. It takes into account the mass of the machine and how that mass is distributed around its axis of rotation.
The moment of inertia is calculated by multiplying the mass of each individual component of the machine by its distance from the axis of rotation, squared. These individual moments of inertia are then summed together to get the total moment of inertia for the machine.
The moment of inertia is important for machines because it affects their ability to resist changes in rotational motion. A larger moment of inertia means that more force is needed to change the rotational speed of the machine, making it more stable and efficient.
The shape of a machine can greatly affect its moment of inertia. Objects with a larger radius of rotation will have a greater moment of inertia, while objects with a smaller radius of rotation will have a smaller moment of inertia. Additionally, the distribution of mass within the machine can also impact its moment of inertia.
Yes, the moment of inertia for a machine can be changed by altering its mass and/or the distribution of that mass. For example, if a machine is made more compact by moving its mass closer to the axis of rotation, its moment of inertia will decrease.