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Table of Contents
                            2302 Design of Joints
	2302.01 Types of Joints
		Introduction
		Joints in Primary Structures
			Welding
			Screws and Bolts
			Riveting
			Solid State Welding
			Friction Stir Welding
			Special Mechanical Joints
		Joints in Thin-Walled Structures
			Thread Forming Screws
			Blind Rivets
			Cartridge Fired Pin Connections.
			Spot Welding
		Adhesive bonded connections
	2302.02 Principles of Design
		Introduction
		Mechanical Properties of Fastenings (Qualitative)
		Classification of connections
		Forces in Connections
		Calculation of Forces in a Group of Fasteners
		Friction Type Bolt Joints
	2302.03 Failure Modes and Deformations
		Introduction
		Failure Modes of Fastenings
			Failure Modes of Fastenings Loaded in Shear
			Failure Modes of Fastenings Loaded in Tension
			Deformation of Connections
	2302.04 Design Strength of Mechanical Fasteners and Spot Welds
		Design Strength of Fasteners Loaded in Shear
			Shear of Fastener
			Hole Bearing
			Tilting and Sheet Tearing
			Edge Failure
			Block tearing failure
			Tension Failure of Net Section
		Design Strength of Fasteners Loaded in Tension
			Tensile Failure
			Pull-Through Failure and Pull-Over
			Pull Out from Underlying Member
		Mechanical Fasteners in Combined Shear and Tension
		Lap joints and pin connections
	2302.05  Design of Welded Connections
		Introduction
		Aluminium Alloys and Welding Technology
		Mechanical Properties of Weld Metal and Heat Affected Zone
		Design of Welds
			Introduction
			Butt Welds
			Fillet Welds
			Design of Welded Connections
		Design Recommendations
			Design Sections
			Resistance in the Ultimate Limit State
			Interaction in Connections
			Influence of Welds on Overall Strength
			Detailing of Welded Connections
	2302.06 Design of Friction Stir Welds
	2302.07 Design of Adhesive Bonded Connections
	2302.08 Literature/References
	2302.09 List of Figures
                        
Document Text Contents
Page 1

Equation Chapter 1 Section 1








TALAT Lecture 2302


Design of Joints


131 pages, 126 Figures (also available as overheads)


Advanced Level


prepared by:
T. Höglund, Royal Institute of Technology, Stockholm


updated according to EC9 by:

Federico M. Mazzolani, University Federico II, Naples


Updated in the aluMATTER project
T. Höglund, Royal Institute of Technology, Stockholm




Objectives:

to provide a view of types of joints in aluminium structures and how to design and

calculate frequently used joints


Prerequisites/Target Group:

Basic structural mechanics and knowledge of design philosophy, structural

aluminium alloys and product forms




Date of Issue: 1994
Revised: 1998
Updated: 2007

EAA - European Aluminium Association

Page 2

2302 Design of Joints

Contents

2302 Design of Joints ....................................................................................................... 2

2302.01 Types of JointsEquation Section 1 .............................................................. 4
Introduction .............................................................................................................. 4
Joints in Primary Structures...................................................................................... 5

Welding................................................................................................................. 6
Screws and Bolts................................................................................................... 8
Riveting............................................................................................................... 11
Solid State Welding............................................................................................. 13
Friction Stir Welding.......................................................................................... 17
Special Mechanical Joints.................................................................................. 19

Joints in Thin-Walled Structures ............................................................................ 25
Thread Forming Screws ..................................................................................... 25
Blind Rivets......................................................................................................... 26
Cartridge Fired Pin Connections. ...................................................................... 32
Spot Welding....................................................................................................... 32

Adhesive bonded connections ................................................................................ 36
2302.02 Principles of DesignEquation Section (Next) ........................................... 38

Introduction ............................................................................................................ 38
Mechanical Properties of Fastenings (Qualitative) ................................................ 40
Classification of connections.................................................................................. 42
Forces in Connections ............................................................................................ 44
Calculation of Forces in a Group of Fasteners ....................................................... 49
Friction Type Bolt Joints ........................................................................................ 53

2302.03 Failure Modes and DeformationsEquation Section (Next)..................... 55
Introduction ............................................................................................................ 55
Failure Modes of Fastenings .................................................................................. 55

Failure Modes of Fastenings Loaded in Shear .................................................. 55
Failure Modes of Fastenings Loaded in Tension ............................................... 56
Deformation of Connections............................................................................... 57

2302.04 Design Strength of Mechanical Fasteners and Spot Welds
Equation Section (Next) ........................................................................................... 60

Design Strength of Fasteners Loaded in Shear....................................................... 60
Shear of Fastener ............................................................................................... 63
Hole Bearing ...................................................................................................... 68
Tilting and Sheet Tearing ................................................................................... 72
Edge Failure ....................................................................................................... 73
Block tearing failure........................................................................................... 73
Tension Failure of Net Section ........................................................................... 74

Design Strength of Fasteners Loaded in Tension................................................... 74
Tensile Failure.................................................................................................... 76
Pull-Through Failure and Pull-Over ................................................................. 77

TALAT 2302 2

Page 65

Characteristic Shear Forces for Rivets
with Short Break Mandrels

2302.04.05

Diameter

d in mm
Aluminium
AA 5052
AlMg2.5

Stainless Steel
Austenitic

Material in Rivet Body

4,8

5,0

6,4

4,0

Aluminium
AA 5056 Steel Monel

800

1100

1100

1600

1700

2600

1600

2400

2600

4400

-

2000

2400

3500

-

6200

2800

4200

4600

-

Characteristic Shear Forces for Rivets
with Short Break Mandrels

alu

Training in Aluminium Application Technologies

Fv,Rk = Characteristic Shear Force Resistance (N/Screw) *

* The Characteristic Tensile Resistace Ft,Rk is Assumed to be 1,25 Fv,Rk (kN/Shear Plane)
The Design Resistace Fv,Rd = Fv,Rk/ M2 and Ft,Rd = Ft,Rk/ M2




H111 H14, H34 H111 H14, H34 T4 T6
4,0 1880 2260 1350 1800 1540 2260
5,0 2940 3530 2120 2820 2410 3530
6,0 4240 5080 3050 4070 3470 5080

Hole
diameter
d 0 mm

5019 5754 6082
EN AW



Shear connections are divided in EC9 into three categories, according to Table 8.4 (see
Appendix). The meaning of each category is summarised in the following:

Category A: Bearing type

In this category steel bolts (ordinary or high strength type) or stainless steel bolts or alu-
minium bolts or aluminium rivets should be used. No preloading and special provisions
for contact surfaces are required.

Category B: Slip-resistant at serviceability limit state

In this category preloaded high strength steel bolts with controlled tightening in con-
formity with prEN 1090-3 should be used. Slip should not occur at the serviceability limit

TALAT 2302 65

Page 66

state. The combination of actions to be considered should be selected depending on the
load cases where resistance to slip is required.

Category C: Slip resistant at ultimate limit state

In this category preloaded high strength steel bolts with controlled tightening in confor-
mity with prEN 1090-3 should be used. Slip should not occur at the ultimate limit state.

Tension connections are divided in EC9 into two categories, according to Table 8.4
(see Appendix). The meaning of each category is summarised in the following:

Category D: Connections with non-preloaded bolts

In this category bolts from class 4.6 up to and including class 10.9 or aluminium bolts or
stainless steel bolts should be used. No preloading is required. This category should not
be used where the connections are frequently subjected to variations of tensile loading.
However, they may be used in connections designed to resist normal wind loads.

Category E: Connections with preloaded high strength bolts

In this category preloaded high strength bolts with controlled tightening in conformity
with prEN 1090-3 should be used. Such preloading improves fatigue resistance. How-
ever, the extent of the improvement depends on detailing and tolerances.

According to EC9, in category C slip-resistant connections as well as in connections
where the design shear resistance Fv,Rd of a fastener is less than the design bearing
resistance Fb,Rd, the distribution of internal forces between fasteners due to bending
moment and to shear must be assumed proportional to the distance from the centre of
rotation and uniform, respectively (see Figure 8.7a of EC9 in the Appendix).
In other cases the distribution of internal forces between fasteners due to bending at the
ultimate limit state may be assumed plastic (see Figure 8.7b of EC9 in the Appendix).

EC9 provides rules for the evaluation of the design resistance of bolts and rivets. In
Table 8.5 (see Appendix) the expressions of the design shear resistance Fv,Rd, the
design bearing resistance Fb,Rd and the design tension resistance Ft,Rd for bolts and
rivets are supplied.
At the ultimate limit state the design shear force Fv,Ed on a bolt (Figure 2302.04.07)
shall not exceed the lesser of (see Table 8.5 in the Appendix):


the design shear resistance Fv,Rd;
the design bearing resistance Fb,Rd.


At the ultimate limit state the design tension force Ft,Ed, inclusive of any force due to
prying action, shall not exceed the design tension resistance BBt,Rd of the bolt-plate
assembly. This should be taken as the smaller of the design resistance Ft,Rd of the bolt
and the design punching shear resistance of the bolt head and the nut Bp,RdB , given by:


p,Rd m p u Mb0,6 /B d t f (4.4)

TALAT 2302 66

Page 130

Figure No. Figure Title (Overhead)
2302.05.03 Definition of Rupture Section and Stresses According to ECCS and

DIN 4113 in a Fillet Weld
2302.05.04 Definition of Stresses in Minimum Throat Section of Fillet Welds
2302.05.05 Design Sections for Butt Welds
2302.05.06 Depth of Design Section for Different Types of Welds with Incomplete

Penetration
2302.05.07 Design Section of Fillet Weld
2302.05.08 Tensile Properties of the Base Metal and the Heat Affected Zone
2302.05.09 Ultimate Tensile Strength of Weld Beads
2302.05.10 Resistance of Butt Welds
2302.05.11 Resistance of Fillet Welds
2302.05.12 Examples of Resistance of Fillet Welds
2302.05.13 Combined Action
2302.05.14 Welds Eccentrically Loaded in Shear
2302.05.15 Eccentrically Loaded Welds in Shear: Calculation of Resistance to Fatigue
2302.05.16 Calculation of Static Resistance I
2302.05.17 Calculation of Static Resistance II
2302.05.18 Eccentrically Loaded Group of Weld in Bending
2302.05.19 Double Fillet Weld in Bending
2302.05.20 Influence of Transverse Welds on Overall Strength I
2302.05.21 Influence of Transverse Welds on Overall Strength II
2302.05.22 Tapering of Thicker Element in a Butt Welded Connection
2302.05.23 Typical Joint Geometry for Tube to Tube-Sheet Weld
2302.05.24 Extended-Land Bevel for Welding Aluminium Pipe
2302.05.25 Example of a Weld at Neutral Axis of Beam
2302.05.26 Design Strength of Welded Joints
2302.05.27 Reinforcement of Welded Butt Joint
2302.05.28 Combining Lap and Butt Joints
2302.05.29 Groove Welds in Extrusions with Integral Backing
2302.05.30 Bulb on Extruded Flange for Improved Weldability
2302.05.31 Offset Flange on Extrusions
2302.05.32 Welds on Lap Joints
2302.05.33 Interlocking Faces on Extrusions
2302.05.34 Slotted Extrusions for Welding to Sheet Components
2302.05.35 Panel Stiffeners
2302.05.36 Tapered Ends on Stiffeners
2302.05.37 Fixed Ends on Stiffeners
2302.05.38 Typical Corner Constructions
2302.05.39 Intersecting Welds
2302.05.40 Slot Welds
2302.05.41 Bracket or Gussets
2302.05.42 Tee Joints at Other Than Right Angles
2302.05.43 Bulkhead to Shell Joints
2302.05.44 Typical Welded Joints in Sheet Metal

TALAT 2302 130

Page 131

Figure No. Figure Title (Overhead)
2302.05.45 Combining Welding and Mechanical Fasteners
2302.06.01 Types of Friction Stir Welds
2302.06.02 Strength of Friction Stir Welds


TALAT 2302 131

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