Load details to be checked on trunnion support 2

[pantheist]

Hello,

There is a scenario where the lifting load & lateral load need to be checked. Attached illustration of trunnion support for reference.
Can anyone guide us with the basics?

Regards

Sundar

 

[r13]

Nothing from this sketch.

You need to shown to what, and how it is attached, what is the lifting mechanism, a radial gate? What is the darkened material in between plates?

 

[pantheist]

This is the sketch received from client. Darkened portion is composite block (Glass reinforced polyester material) which can withstand temperature up to +700 degree Celsius. compression strength is about 30 Mpa at its operating temperature (700 Deg C)

What are the factors which determines maximum lateral load & tension on this arrangement?

 

[r13]

Because of the great number of factors that define a GRP composite, the range of mechanical and other physical properties is very wide.

It is called a GRP composite. Ask the client for property sheet, especially flexibility in lateral deformation. As it deforms, the bolts might experience bending on top of applied shear (lateral) force.

 

[dhengr]

Sundarzplanet:
Many of you guys seem to have no idea how important general proportions, load magnitudes, etc. are to an experienced engineering eye, assuming you would like real answers to your questions. An 8” brick corbel and a 100’ flag pole are both cantilevers, but they are treated much differently in their design. I don’t give a damn about A, B, C and D dimensions, I would like to know if the plate side “A” is about 100mm or 1000mm, and if the lifted load is 100lbs. or 100 tons, give or take a few pounds. Have you really drawn and studied a free body diagram (FBD) of that system? Do you really know the mech. props. of the insulation material, the thermal washers, the stl. pls. and the bolts, etc. What is the approx. tension in the bot. bolts during the lifting process? What is the compression force in the insul. mat’l. and how is it distributed? What do the thermal washers do to the rotation and strength of the system? If you are really an engineer, you should be able to start sorting these things out, and providing a sketch showing them. Otherwise, your sketch just shows you have two levels of people who have no idea what they are doing, on an important design problem, the engineer and their client. Where is the lifting load applied, and what prevents it from slipping of the end of the trunnion? Answer the questions above and come back here with a good FBD and you might generate some meaningful discussion, otherwise you are asking us to waste our time playing 20 questions with you.

Edit: By the way, I would not expect the 4 bolts to take the shear loading in that detail during the lifting process.

 

[pantheist]

@dhengr - I have started my career & lacks experience in looking at things design point of view. I would say that the details given in your thread is really helpful to understand the basics of this kind of scenario in order to arrive arrive at a solution.

Details of the properties of the GRP is as follows:

Compressive strength (at 20 deg C) M Pa 90
Compressive strength (at 350 deg C) M Pa 38
Compressive strength (at 500 deg C) M Pa 31
Compressive strength (at 700 deg C) M Pa 29
Flexural strength (at 20 deg C) M Pa 30
Flexural strength (at 350 deg C) M Pa 16
Flexural strength (at 500 deg C) M Pa 13
Flexural strength (at 700 deg C) M Pa 13
Density g/cu cm 1.6

Bolt size is M20 which has the loading capacity as 15.5 KN

Thermal washer is of the same material. I am not sure whether the bottom plate is welded to the structure beneath (which is not shown in the sketch). I think that analyzing of lifting load is applicable only when the bottom plate is welded to the structure or had it been given with hold down guide. Please correct me if I am wrong

 

[dhengr]

Sundarzplanet:
But, you are begging one question, are you an engineer by education and do you think like an engineer? You should not be designing these types of things, or approving them, if you don’t know what you are doing. Do you have someone at your company who can help and guide you in this process? Can you draw a FBD of that trunnion, with dimensions, forces, moments, etc? Answer the rest of my questions in my first post. Reread the post for its full content. The sketch from your client may not be the best solution. If they had all the answers, they wouldn’t be coming to you for help and engineering. But, you better offer real engineering not just some b.s. Added questions: what is E (modulus of elasticity) of the insulating material, and is it the same in tension and compression, other mech props? What is the product name and the supplier? Is the compressive strength in the elastic range or is it a crushing strength (inelastic)? Do you ever need to lift this vessel when it is at max. temp, or only when it is cold? It looks like the whole issue is that they do not want these trunnions conducting heat and sticking out through an insulation layer/cover. Why not remove the trunnions after lifting the vessel, and provide an insulation cover over those areas, or just a complete cover over the trunnions? Of course, this will require some redesign of the whole trunnion and its insulation. You can not get by with such a vague sketch for a design problem like this, you are leaving way too much to the imagination of someone else. M20 stove bolts look a little sketchy to me, as do only four bolts. Are you upending this vessel and lifting it too?

 

[pantheist]

@dhengr

First of all, We are not designing any system. We have received an pipe support inquiry for suggestions & I am voluntarily picking this one to study the parameters under such conditions where we are able to give suggestions. Just collection data/information for my understandings on my own. But client neither give any details of the trunnion nor we know whether this structure comes beneath the vessel.
I can understand the question I put up is vague & lacks details to introspect.

So no big deals! - I am a novice

However, Thanks for the response