Effective width for fasteners 10

[dik]

When using a high strength bolt clamping two pieces of metal together. What effective width do you use on each side of the bolt hole to determine the effective flexural width? Is there a value prescribed by code? or by common useage? I typically consider 4 x the thickness of the material on each side for a total of 8 x the thickness.

For a 1/4" thick plate, I would normally use an effective width of 2".

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[canwesteng]

I don't think there is a basis for any multiple of t as the width. Usually a 45 degree angle is used, as kind of a quick and dirty assumption that it will be more conservative than a proper yield line approach. If you were to crunch the actual yield lines you would see the thickness does not affect the controlling pattern.

 

[dik]

A portion of the width will be effective... I was just wondering what others would use. I'm comfortable with 6xt for the total width, considering the bolt, nut and washer will contribute. It was just a 'meatball' approach that I often use for expediency.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[dik]

The thickness was just used for the example to determine the width. The actual plate is 5/8" thick.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[JLNJ]

I would specify a nice, thick washer to increase my effective width and use 4t from the washer edge.

 

[Tomfh]

The effective width is more a function of span and support conditions than it is plate thickness. A longer span mobilizes a much wider effective width. For a monolithic steel plate you will typically obtain an effective width similar to the span distance, which is reflected in Celt83's yield line drawing.

 

[dik]

Thanks, Tom...

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[dik]

dvd... thanks...

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[BAretired]

I would have answered this differently a couple of months ago, but I think this is the correct failure mode.

 

[dik]

I suspect it would be close... thanks, BART. I'll see how it compares to what I used. Project is already done and out.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[ALK2415]

Good research thoughts here
thanks to you ALL
Also, sine you want to increase flanged diameter of base plate, why you don't apply double nuts technic ?