Eccentrically Loaded Bolt Group: ONLINE COEFFICIENT CALCULATOR

Here is another post for Structural Designers specializing Connection Design. Non-engineers may opt to skip reading this post. They might find this blogpost not interesting.

Topics on INSTANTANEOUS CENTER OF ROTATION method on bolted connection design are very scarce on the internet. Scarce as it may seem, the design of bolted connections using ICR Method is very cumbersome: an engineer needs a table of bolt coefficients to calculate strength of a Bolt Group. In my previous post, Eccentrically Loaded Bolt Group: Analysis and Design using 'INSTANTANEOUS CENTER of ROTATION METHOD' with VBA for Excel Implementation, I dealt with how the method offers both ease and difficulty in bolted connection design. Then, in an attempt to help fellow engineers in the same field surpass the same design problem, I provided in the same post a Visual Basic Code that calculates the instantaneous center of an eccentrically loaded bolt group that eventually calculates the bolt coefficient, C. The code is a VBA implementation that runs in Microsoft Excel Environment.

Not satisfied with the Visual Basic Code alone running in Excel, I thought of running the code within my blogpost. It took me at least one week of research, which includes studying the structures of Javascript and VBScript, before I finally come up with the design of this calculator. I opted for VBScript as the code for instantaneous center of rotation I did earlier is written in Visual Basic; it only needed some few tweaks. Before deciding to write this post, I searched the internet for similar program. I found one in WebCivil.com but is not fully functional: you need to buy a license to be able to use the program.

Here, I wrote and posted the program for free. I intend to help fellow engineers hasten their burden in design work. Just enjoy using the calculator.

ECCENTRICALLY LOADED BOLT GROUP -- COEFFICIENT CALCULATOR

BOLT GROUP DATA			BOLT GROUP GEOMETRY
Rows
Columns
Gauge		in.
Pitch		in.
Eccentricity		in.
Load Angle		deg
CALCULATION RESULTS:

Note: yRo is negative if I.C. lies below the horizontal red line and positive otherwise.

Parameter Descriptions:

ex Load Eccentricity c Number of Bolt Columns r Number of Bolt Rows I.C. Instantaneous Center

g Horizontal Spacing of Bolts p Vertical Spacing of Bolts Ø Load Rotation Angle Pa Allowable/Design Load

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Warning:
Running this program may cause your web browser to slow down. This may happen for a very large bolt input associated with non-zero eccentricity. When this happens, however, you will be prompted with a message by your web browser whether or not to stop running the script. You may also opt to press Ctrl+Break key combination to force-stop the script.

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