Bolt Calculation

Make a sketch since your description is not clear enough.

why are bolts being used as load bearing element?

negelcting self-weight, each bolt would be acted on by uniform load of the molten iron [total weight of iron/14]

assuming self-weight, load acting on a bolt would be sum of load acting due to molten iron in crucible + load exerted due to weight of all bolts above the bolt in consideration

For the bolt on top, self-weight acting would be zero. For bolt below it self-weight acting = (weight of each bolt)x(number of bolts above it)

add this load to the load acting on a column [total load of molten iron/14] and you will get load acting on each bolt

the formula you must use to compute the force exerted due to weight of the iron = mass density of molten iron X base area of cylinder X height of cylinder X acceleration due to gravity

the formula you have used has a different purpose

thanks for your reply, the formula i used is because of the "ferrostatic phnomenon". this is same as the case of dam. the vertical face of dam is facing the hydrostatic load of water apart from self weight of water on the base of river. its true that the weight load on top bolts will be zero and also the ferrostatic load will be zero. i have checked the bolt on self load+molten metal load condition and it is safe. but i want to check for ferrostatic load. i dont know how to send the sketch in this group.

you may upload the image on http://imageshack.us/ and just post the link here - it should suffice

hi slugger here is the image link for my crucible question. kindly bail me out http://img399.imageshack.us/my.php?image=83498920ct6.png link:

The image is very different from what I had imagined it to be, based on which I responded

My answer is no longer relevant/applicable

i couldnt understood your reply. are you still on the way for the solution. kindly try for it.

I will try to help you out as well, now that it is more clear with the sketch -

Just to make sure I fully understand, I have a few questions -

1. Is the crucible fully supported on the bottom, so that there is no "weight" load of the molten iron (ie no shear loading on bolts)?
2. Is the only load on the bolts due to the deformation of the crucible radially?
3. Do we need to account for thermal expansion?
4. Do you envision the only load on the bolts as compressive?
5. Are the bolts preloaded at all? If so, at what temperature (ambient or hot)?
6. What are the other dimensions? Crucible thickness, bolt size, bolt length to column

Just wondering if you could look at this another way -

Can you measure any deflection in the columns from a cold & empty state to a hot & full state? If so, would it be possible to approximate the loads by "reverse" calculating the column loading.

I wouldn't necessarily say that the bolt loads at the bottom are maximum, because the bottom of the cylinder will add a lot of support to the wall and thus restrict radial strain due to pressure loading. I don't have the formula with me right now for stress/deflection in a cylinder - because how I am looking at this is to find the deflection in the walls due to the loading and superimpose that position into each bolt at each particular elevation.

This will of course require a bit more information:

1. Elevations of the bolts / distances between them in relation to crucible top/bottom.
2. Thicknesses and material of the crucible.
3. Are the bottoms of the columns fixed as well as the top?

dear slugger/guest here is the detailed dimension (image file) and answers of your question. 1. Is the only load on the bolts due to the deformation of the crucible radially? – Yes But In Addition To Thermal Expansion Load We Have Take The Account Of Ferrostatic Loading. 2. Do we need to account for thermal expansion? - Yes 3. Do you envision the only load on the bolts as compressive? - Yes 4. Are the bolts preloaded at all? If so, at what temperature (ambient or hot)? -Yes , Preload of 8000lb, at 1400 degree c 5. What are the other dimensions? Crucible thickness, bolt size, bolt length to column- Crucible Thickness= 6", Bolt Size= 1.5"Dia And 12" Length 6. Elevations of the bolts / distances between them in relation to crucible top/bottom. – See image at "http://img227.imageshack.us/my.php?image=loadingqt7.png" 7. Thicknesses and material of the crucible- Thickness Is 6" And Material Is LC45 Cement. 8. Are the bottoms of the columns fixed as well as the top?- Yes It Is Fixed At Top As Well As Bottom the total load of metal is 35 ton steel do ask more if required regards manas