This calculator analyses and checks each bolt in a bolt group for in-plane and of-of-plane loading. The bolt group is analysed using the Instantaneous Centre of Rotation (ICR) concept. The shear force, tension (pull-out) force and combined action in each bolt is then checked to validate the bolt group.
All calculations are performed in accordance withAS4100-2020.
Calculation
Assumptions
Bolt Properties
Bolt grade
:8.8
Tensioning spec
:S
Bolt type
:8.8/S
fuf
:830MPa
Bolt category
lj
:0 mm
kr
:1.0
Bolt splice
Threads?
:Included
Threads included or excluded
n
:1
Shear planes
μ
:0.3
Slip factor (for 8.8/TF bolts only)
Bolt Group Geometry
In-plane Loads
Out-of-plane Loads
Single Bolt Capacities
Bolt Group Check
V*f_max
:126.7kN
N*tf_max
:20.5kN
Bolt Group Analysis
ϕ
:0.8
Capacity factor
Minimum required bolt
:M24
Evaluation of each bolt in the bolt group is provided below:
0
0
105
0
SAFE
SAFE
2
0
50
62
0
SAFE
SAFE
SAFE
3
0
100
74
7
SAFE
SAFE
SAFE
4
0
150
127
20
SAFE
SAFE
5
50
0
88
0
SAFE
SAFE
SAFE
6
50
50
22
0
SAFE
SAFE
SAFE
SAFE
7
50
100
47
7
SAFE
SAFE
SAFE
SAFE
8
50
150
113
20
SAFE
SAFE
👉Note,
xi,yi
are the bolt coordinates from an origin point defined by the bottom left bolt and are in
mm
. The design loads
Vf∗,Ntf∗
are in
kN
.
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).
A typical connection with a bolt group is a beam to column bolted connection.
Beam to column connection
Bolt capacity
Bolts are required to be checked individually for shear and tensile loads, as well as with a combined action check.
The shear and tensile capacities of bolts are both based on the minimum tensile strength
fuf
rather than the yield strength.
Explore the toggles below for the bolt capacity equations to AS4100.