Slip Critical Presentation - Joel Kerkhoff

8/2/2019 Slip Critical Presentation - Joel Kerkhoff

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3/26/2009 Slip Resisting Bolted Connections - Joel Kerkhoff

Slip Resisting Bolted

Connections

By: Joel Kerkhoff

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Source: Remi M. www.flickr.com/photos/remi_m
http://www.flickr.com/photos/remi_mhttp://www.flickr.com/photos/remi_m


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Outline

Introduction

Uses

History & Code dev.

Basic Theory

Code requirements

Spreadsheet

Research

Testing @ UBC Conclusion

Questions

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Port Mann Bridge deck connection

(Remi M. Flikr)


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Introduction

What is a slip-resisting connection?

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Two components

Tensioned bolts

Steel faying surfaces

A simple friction connection

source: unknown


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Where is it used?

Locations:

Stress reversal / fatigue

Vibration

Oversize/slotted holes

Bolts & welds share load

Where joint slippage is detrimental

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Where is it used? - examples

Slot-bolted connection

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Karuah Bridge,

South Wales, Australia

(source www.rta.nsw.gov.au Roadsand Traffic Authority, NSW)

Source: www.eng.nus.edu.sg/EResnews/9711/nov97p1.html
http://www.rta.nsw.gov.au/http://www.eng.nus.edu.sg/EResnews/9711/nov97p1.htmlhttp://www.eng.nus.edu.sg/EResnews/9711/nov97p1.htmlhttp://www.rta.nsw.gov.au/


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Where is it used? - examples

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Falkirk Wheel, ScotlandSource: www.lucs.org.uk/falkirk_wheel.htm

Source: www.pbase.com/geoff_c
http://www.lucs.org.uk/falkirk_wheel.htmhttp://www.pbase.com/geoff_chttp://www.pbase.com/geoff_chttp://www.lucs.org.uk/falkirk_wheel.htm


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History and code development

Historical

Rivets

Batho & Bateman 1934

RCRBSJ (now RCSC) 1947

ASTM 1949

American codes/guides:

RCSCwww.boltcouncil.org

Specification for Structural Joints Using

ASTM A325 or A490 Bolts AISC

Guide to Design Criteria for Bolted andRiveted Joints (Kulak, Fisher, Struik)

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http://www.boltcouncil.org/http://www.boltcouncil.org/


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Basic Theory

Bolts provide the Normal Force (N)

m depends on faying surfaces

Ff = mN Vr = ks * [bolt tension]

Complexities in both factors.

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Source:en.wikipedia.org/wiki/Friction
http://www.wikipedia.org/wiki/Frictionhttp://www.wikipedia.org/wiki/Friction


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Canadian Code Design

CAN/CSA-S16.1-01 cl. 13.12.2

Vs = 0.53*c1*ks*m*n*Ab*Fu

Fu = specified minimum tensile strength

Ab = bolt cross sectional area

n = number of bolts

m = number of shear planes

ks = mean slip coefficient

c1 = 5th percentile coefficient

Slip resistance is a Service Limit State

Must design as regular bolt connectionfor Ultimate Limit States!

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Canadian Code Design

CAN/CSA-S16.1-01 Table 3

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Contact Surface of bolted Parts Friction c1

Class Description ks A325 bolt

AClean Mill Scale, or blast-cleaned withClass A coatings 0.33 0.82

BBlast-cleaned, or blast-cleaned withClass B coatings 0.5 0.89

C

Hot-dip galvanized with wire brushed

surfaces 0.4 0.9


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Excel Spreadsheet

Compute slip resistance

Compute bolts for given shear

Simplify user input Check for errors

Eliminate need to use Blue Book

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source: Microsoft


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Research

Prof. J. Hajjar - University of Illinois

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600 kip MTS Uniaxial testing Machine

Blast cleaned steel test sample

& 50kip clamping force

Ongoing

International

Source: www.nsel.cee.illinois.edu

Source: www.nsel.cee.illinois.edu


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Testing at UBC

Steel test sample

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100 Ton Baldwin testing machine

12 samples

o As Is / Mill scaleo Blast-cleaned

3 Samples left

Image sources: Jalayer, Stiemer and Youn. Experimental Investigationsof Slip Resistant Connections for Weathering Steel


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Testing at UBC - results

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Table: Slip Test Results

Surface Type Specimen Type Mean Slip

Load [kips]

Standard Dev

[kips]

COV

As Is Plate-to-flange 63.0 9.0 0.14

As Is Plate-to-plate 68.1 5.1 0.07

As Is All specimens 65.0 7.9 0.12

Blast-cleaned Plate-to-flange 62.6 2.4 0.04

Surface

Type

Specimen

Type

5th Percentile Coefficient

of Friction [ ]

Estimated

ks [ ]

S16.01

ks

As Is Plate-to-flange 0.35 0.42 0.33

As Is Plate-to-plate 0.43 0.520.33

As Is All specimens 0.37 0.45 0.33

Blast-

cleaned

Plate-to-flange 0.42 0.46 0.50

Data source: Jalayer, Stiemer and Youn. Experimental Investigations of SlipResistant Connections for Weathering Steel


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Concluding comments

Summary

Simple

Complicated

Acknowledgements & Resources

Professor Stiemer & Professor Youn

G.L Kulak Various publications

University of Illinois NSEL website test pictures

Google for finding some of the pictures

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Questions

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Source: www.ezdiyelectricity.com/?p=526
http://www.ezdiyelectricity.com/?p=526http://www.ezdiyelectricity.com/?p=526

Slip Critical Presentation - Joel Kerkhoff

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