Hunch moment connection 1

[hm5k]

Hello Friends,

Please help me to get some technical references or any sample calculation for hunch moment connection.

Thanks

 

[SteelPE]

Do you mean haunch moment connection? And, what material are you using for this connection, steel, concrete, other?

 

[KootK]

Assuming that we're talking steel, try AISC's design guide on tapered member design. MBMA collaborated on that which makes it extra credible in my opinion.

The greatest trick that bond stress ever pulled was convincing the world it didn't exist.

 

[hm5k]

Connection for steel,

See attached sketch for connection that i have to validate for 1.2 time of plastic moment capacity.

Connection design based on LSM

Please provide some information or connection sample.

thanks

 

[hm5k]

please help me on this

 

[JoshPlumSE]

Hmmm..... Basically a bolted end plate moment connection. Similar (but larger) than those shown in AISC Design Guide 4.

Some thoughts on this:
1) Get hold of some of the papers that DG-4 was based on. You can then derive your own yield lines for this connection and use that same procedure to come up with the flexural yielding of the plate. I'm specifically thinking of "unified design of extended end-plate moment connections subject to cyclic loading" a PhD dissertation by Emmett A. Sumner

2) Sloping the haunch back at that tight angle may make it difficult access or tighten some of those bolts. Something to keep in mind for construct-ability.

 

[Archie264]

Wow, that's quite a connection. What is "LSM", by the way?

 

[JedClampett]

Isn't there anyone in your office that can guide you on this? Someone apparently set this up. Ask them.
It seems that this is a pretty inefficient way to get help. Vague question followed one hour later with a sketch and three hours later with a "please help me on this."

 

[JoshPlumSE]

I should point out that the haunch is so deep that it should not be too difficult to achieve the 1.2*Mp. I'm not used to seeing haunches that are this deep. I've seen them increase the depth of the connection by 50%, not by 150% like this one seems to.

I would be cautious to make sure you design to 1.2*Mp + Vp*distance between hinge location and face of column. As the distance is significant enough to cause a good bit more moment.

 

[BAretired]

LSM is Limit States Method. My suggestion follows:

The moment arm is 170+600 = 770 mm. Tension = 1.2*Mp/770 to be taken by eight upper bolts. Bolts each take a shear of Vp/14 where Vp is the shear corresponding to 1.2*Mp.

Use yield line theory to check column flange and attached plate. Add doubler plates if necessary.

Compression is centered on lower stiffener plate and is numerically equal to tension, i.e. 1.2*Mp/770. Check bending of plate against column flange. Check bearing capacity of stiffener combined with the effective area of column web.

BA

 

[JoshPlumSE]

In the US, the practice is to assume that only the bolts on the compression side of the connection can resist shear. It makes the design procedure simpler. Because we can then ignore tension / shear interaction for the bolts.

If you assume that all the bolts resist shear then you would want to check how this affects the tension capacity of the most heavily loaded bolts.

 

[dhengr]

Hm5k:
I hope your analysis accounts for the fact that a haunched beam end like that will attract more negative moment, whatever the loading. And that, in your further analysis, the worst moment condition is likely to be near the inner end of the haunch and the primary beam.

 

[hm5k]

Hello to All,

Here i attached hunch moment connection design based on IS-800 (2007) Code with Limit State method.

Please review & provide you input for anything missing or wrong considerations.

Your comment will help me lot to correct it.

Thanks