Analysis of an Overlapping Bolted Connection of Steel Sheets with Ordinary Bolts

Objective: Check the mode for calculating bolted connections

Task: Check an overlapping connection of 300х14 mm sheets with ordinary bolts from steel grade С275 for a shear force.

Source: Moskalev N.S., Pronosin J.A. Steel Structures. Handbook / M.: ASV Publishing House, 2010. p. 100.

Compliance with the codes: SNiP II-23-81*, SP 16.13330, DBN B.2.6-163:2010.

Initial data file:

2.5.sav;
report — Kristall2.5.doc

Initial data:

N = 800 kN	Shear force;
Rbp = 450 MPa,	Steel grade C275; Thickness of the gusset plate 8 mm, middle plate 14 mm;
Rbs = 190 MPa,	Bolts of 5.6 strength class and C accuracy class; Diameter of bolts 20 mm, diameter of holes 22 mm;
γc = 1,1	Service factor;
γb = 0,9	Service factor  of the bolted connection.

 

KRISTALL parameters:
Steel: C275

Group of structures according to the table 50* of SNiP II-23-81* 3

Importance factor	1
Service factor	1
Service factor  of members to be joined	1
Product of the joint service factor (γb) and the service factor  of members to be joined (γc)	1
Design shear strength of bolts Rbs	190 N/mm2
Design bearing strength of bolt elements Rbp	459.139 N/mm2

 

Type:	Bolts:	Parameters:
	Diameter of bolts 20 mm Clearance 2 mm Diameter of holes 22 mm Class of bolts 5.6 Accuracy class B or C	m = 1 n = 3 a = 60 mm b = 70 mm c = 50 mm t = 8 mm t0 = 14 mm

 

Internal forces and moments:

N = 800 kN
M_y = 0 kN*m
Q_z = 0 kN

Manual calculation (SNiP II-23-81*):
1. Design shear resistance of the bolts was calculated as follows
R_bs = 0.38R_bun = 0.38 × 500 = 190 MPa (see table 5*).
2. Design bearing resistance of the bolts was calculated as follows (see table 5*):

\[ R_{bp} =\left( {0,6+340\frac{R_{un} }{E}} \right)R_{un} =\left( {0,6+340\cdot \frac{370}{2,06\cdot 10^{5}}} \right)\cdot 370=447,95 \quad MPa. \]

3. Shear strength of the bolts was calculated according to the following formula:

\[ N_{bs} =R_{bs} A_{b} n_{s} \gamma_{b} \gamma_{c} =190\times 10^{3}\times 3,14\times 10^{-4}\times 2\times 0,9\times 1,1=118,127 \quad kN. \]

4. Bearing strength of the bolts was calculated according to the following formula:

\[ N_{bp} =R_{bp} D\left( {\sum\limits_i {t_{i} } } \right)_{\min } \gamma_{b} \gamma_{c} =447,95\times 10^{3}\times 20\times 14\times 10^{-6}\times 0,9\times 1,1=124,172 \quad kN. \]

Comparison of solutions:

Factor	Manual calculation	KRISTALL	Deviation from the manual calculation, %
shearing of bolts	800/8/118,127 = 0,8465	0,846	0,06
bearing	800/8/124,172 = 0,805	0,809	0,5