Introduction
This calculator allows the user to analyse and check each bolt within a bolt group to ensure compliance with the Australian Standard AS 4100. The user defines the bolt group geometry by inputting the number of rows and columns of bolts. Using user input loads, the calculator then checks the shear force and tension (pull-out) force in each bolt.
A typical connection with a bolt group is a beam to column bolted connection.
❗This calculation has been written in accordance with AS 4100.
Calculation
⬇️Inputs
Bolt Properties
Bolt grade
:8.8
Bolt category / tightening method
:S
Threads in shear plane?
:1
Length of lap splice
:0mm
Slip factor
:100
Bolt Group Geometry
Number of rows in bolt group
:4
Spacing between rows
:50mm
Number of columns in bolt group
:2
Spacing between columns
:50mm
Width of baseplate
:100mm
Depth of baseplate
:200mm
Loads
In-Plane Load:
F*x
:100kN
F*y
:200kN
ey, F*x eccentricity,
:0.1m
ex, F*y eccentricity
:0.2m
M*z (kNm)
:30Note, ex & ey are the force eccentricities from the weld group centroid. Refer to Output --> Weld Group Geometry for the coordinates of the weld group centroid in order to determine your ex and ey.
Out-of-Plane Load:
V*o
:100kN
e, V*o eccentricity
:0.3m⬆️Outputs
Bolt Properties
Bolt type
:8.8/S
Capacity reduction factor, ϕ
:0.8
Reduction factor for lap connections, kr
:1.0
Minimum tensile strength of a single bolt, fuf
:830MPa
Bolt Group Geometry
Total number of bolts
:8
Location of the Instantaneous Centre of Rotation (ICR):
x coordinate of bolt group centroid (mm)
:25.0mmx coordinate of bolt group centroid (mm)
y coordinate of bolt group centroid (mm)
:75mmy coordinate of bolt group centroid (mm)
Second moment of areas:
I_x (mm4)
:25000
I_y (mm4)
:5000
I_p (mm4)
:30000
Loads
In-Plane Resultant Forces:
Resultant applied in-plane moment, M*1 (kNm)
:60.0Out-of-Plane Resultant Forces:
Resultant applied out-of-plane moment, M*o (kNm)
:30.0
⬆️Design Checks
Critical shear force applied on the bolt group, V*f
:180kN
Critical tearout force applied on the bolt group, N*tf
:45kN
Minimum required bolt
:M30
Evaluation of each bolt in the bolt group:
| 139.75 | 45 | | | | | SAFE | SAFE | |
2 | | 45.07 | 15 | | SAFE | SAFE | SAFE | SAFE | SAFE |
3 | | 67.31 | -15 | | | SAFE | SAFE | SAFE | SAFE |
4 | | 164.41 | -45 | | | | | SAFE | SAFE |
5 | | 156.62 | 45 | | | | | SAFE | SAFE |
6 | | 83.85 | 15 | | | SAFE | SAFE | SAFE | SAFE |
7 | | 97.63 | -15 | | | | SAFE | SAFE | SAFE |
8 | | 178.97 | -45 | | | | | SAFE | SAFE |
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💬 We'd love your feedback on this template! It takes 1min
Explanation
Connections in building structures use a minimum of two bolts and often more than eight bolts. The bolts used in a connection form a bolt group. A bolt group may be acted on by loads and bending moments in the plane of the bolt group (in-plane) or at right angles to it (out-of-plane loading).
See below for tabulated bolt data and information about the analysis of bolt groups.
Analysis of bolt groups
Geometry for Class 4.6 and 8.8 bolts
Design capacity for Class 4.6 and 8.8 bolts