CHANGES IN THE JULY 7 2016AISC SPECIFICATION

FROM THE 2010 EDITION

TED GALAMBOS, UNIVERSTY OF MINNESOTAFOR THE

2018 STRUCTURAL ENGINEERING SEMINARS

A PLACE TO LOOKAISC “MODERN STEEL CONSTRUCTION”SEPTEMBER 2017 ISSUE:

P. 17“STRUCTURAL INTEGRITY – AND REORGANIZATION”

P. 64“15TH EDITION OF STEEL CONSTRUCTION MANUAL NOW AVAILABLE”

18 “SIGNIFICANT” TECHNICAL MODIFICATIONS

• FOLLOWING ARE SOME OF THEM:• STRUCTURAL INTEGRITY:• PERFORMANCE CHARACTERISTIC OF A

STRUCTURE INDICATING RESISTANCE TO CATASTRPHIC FAILURE.

• MINIMUM STRENGTH OF CONNECTIONS AND BRACING MEMBERS

• INDEPRNDENT OF REGULAR STRENGTH DESIGN• MAY BE REQUIRED BY APPLICABLE BUILDING

CODE

SOME CHANGES ARE,WELL, YOU CHOOSE THE ADJECTIVE

• CHAPTER G: DESIGN OF MEMBERS FOR SHEAR• CHANGE A SHEAR BUCKLING COEFFICIENT

FROM 5.0 TO 5.34• PERMIT TENSION FIELD ACTION FOR

TRANSVERSELY STIFFENED SHEAR PANELS FOR PANELS WITH h/bf > 6 WITH A NEW FORMULA

MORE:

• INCREASED REBAR STRENGTH TO 80KSI FOR COMPOSITE COLUMNS

• ADDED PROVISIONS FOR DIRECT DESIGN FOR FRAMES WITH COMPOSITE MEMBERS

• REVISED RULES FOR WELDS COMBINED WITH BOLTS

• INCREASED STANDARD HOLE SIZE TO 1/8 “ ABOVE BOLT DIAMETER FOR 1” BOLTS AND BIGGER

WIDTH-THICKNESS LIMITS IN STEEL BEAM DESIGN 2010 AND 2016 AISC SPECIFICATIONS.

TED GALAMBOS, 2018 UNIVERSITY OF MINNESOTA

STRUCTURAL ENGINEERING SEMINAR SERIES

MATERIAL PROPERTIES Fy 50ksi:= E 29000ksi:= n 0.3:=

LENGTH OF BEAM: Lb 30ft:= CROSS SECTION: WT15X54

d 14.9in:= Sx 32in3:= wself 54lbfft

:=Lbd

24.161=

bf 10.5in:= Zx 57.7 in3:= Iy 73in4:=

tf 0.76in:= J 2.49in4:=

tw 0.545 in:= Cw 17.3in6:=Lb

10000.36 in=

dtw

27.339=

ry 2.15in:= ro 6.31in:=

y 4.01in:=Ix 349in4:=

Lbry

167.442=bf

2 tf×6.908=

Calculate nominal moment capacity under uniform moment. Bending is about the x-axis.

a) flange is in compression.

Mp min Fy Zx× 1.6 Fy× Sx×, ( ):= My Fy Sx×:=

Lateral-Torsional Buckling

Lp 1.76 ry×EFy

×:= Lr 1.95EFy×

Iy J×

Sx× 2.36

FyE

×d Sx×

J1+×:= B 2.3

dLb×

IyJ

×:=

MnLTB Mp Lb Lp£if

Mp Mp My-( )Lb Lp-( )Lr Lp-

×-éêêë

ùúúû

Lp Lb< Lr£if

1.95 E×Lb

Iy J×× B 1 B2++( )×éêë

ùúûotherwise

:=

MnLTB 2.086 103

´ in kip××=

Flange local buckling

bpf 0.38EFy

× 2× tf×:= brfEFy2× tf×:= Sxc

Ixy

:=

MnFLB 1.6 My×( ) bf bpf£if

min 1.6 My× Mp Mp 0.7Fy Sxc×-( )bf bpf-

brf bpf-×-

éêêë

ùúúû

, éêêë

ùúúû

bpf bf< brf£if

0.7 E× Sxc×

bf

2 tf×

æççè

ö÷÷ø

2otherwise

:=

MnFLB 2.56 103

´ in kip××=

MnFL min MnLTB MnFLB, ( ):= MnFL 2.086 103

´ in kip××=

b) Flange in tension

Lateral -torsional buckling MnLTBw min My1.95 E×Lb

Iy J×× B- 1 B2++( )×, éêë

ùúû

:=

MnLTBw 1.291 103

´ in kip××=

Web local buckling. (THIS IS NEW IN 2016)

dp 0.84EFy

× tw×:= dr 1.52EFy

× tw×:=

Fcr Fy d dp£if

Fy 1.43 0.515dtw×

FyE

×-æççè

ö÷÷ø

×éêêë

ùúúû

dp d< dr£if

1.52 E×

dtw

æçè

ö÷ø

2otherwise

:=

Fcr 42.268 ksi×=

MnWLB Fcr Sx×:=

MnWLB 1.353 103

´ in kip××=

Mnw min MnLTBw MnWLB, ( ):= Mnw 1.291 103

´ in kip××=

WIDTH-THICKNESS LIMITS IN STEEL COLUMN DESIGN1953, 1969-2010 AND 2016 AISC SPECIFICATIONS.

TED GALAMBOS, 2018 UNIVERSITY OF MINNESOTA

STRUCTURAL ENGINEERING SEMINAR SERIES

MATERIAL PROPERTIES Fy 50ksi:= E 29000ksi:= n 0.3:=

LENGTH OF COLUMN: L 14ft:=

N O N S L E N D E R

S L E N D E R

00

rl

w

dt

l =

yF

crF

CROSS SECTION: WT15X54

ALLOWABLE STRENGTH ACCORDING TO APR. 17 1963 EDITION

d 14.9in:= tw 0.545in:=dtw

27.339= bf 10.5in:= tf 0.76in:=

Sec 1.9.1, PROJECTING ELAMENTS UNDER COMPRESSION;

WHEN A PROJECTING ELEMENT EXCEEDS THE PRESCRIBED WIDTH-TO-THICKNESS RATIO , BUT WOULD CONFORM TO SAME AND WOULD SATISFY THE STRESS REQUIREMENTS WITH A PORTION OF ITS WIDTH CONSIDERED AS REMOVED, THE MEMBER WILL BE ACCEPTABLE.

EFFECTIVE WIDTH: de 0.7428EFy

× tw×:= de 9.75 in=

EFFECTIVE AREA: A 15.9in2:= Ae A d de-( ) tw×-:= Ae 13.093 in2×=

EFFECTIVE RADII OF GYRATION: rxe 2.557 in= rye 2.368 in=

COLUMN STRENGTH (Sec. 1.5.3) Cc2 p

2× E×Fy

:= re min rxe rye, ( ):=

FS53

38Lre×

1Cc×+

18

Lre

1Cc×æ

çè

ö÷ø

3×-

éêêë

ùúúû

Lre

Cc£if

2312

otherwise

:= FS 1.879=

Fa 112

Lre

1Cc×æ

çè

ö÷ø

2×-

éêêë

ùúúû

FyFS×

éêêë

ùúúû

Lre

Cc£if

p2 E×

Lre

æçè

ö÷ø

2 1223æçè

ö÷ø

×

otherwise

:=Fa 20.764 ksi×=

Pa Ae Fa×:= Pa 271.858 kip×=

ALLOWABLE STRENGTH ACCORDING TO FEB. !12, 1969 EDITION

SEC.1.91 UNSTIFFENED ELEMENTS UNDER COMPRESSION

Q 0.534:= Cc2 p

2× E×Q Fy×

:= Cc 146.423=

rx 4.69 in:= ry 2.15in:= r min rx ry, ( ):=

FS53

38

Lr×

1Cc×+

18

Lr

1Cc×æ

çè

ö÷ø

3×-

éêêë

ùúúû

Lr

Cc£if

2312

otherwise

:=

FS 1.848=Check Table C! limits

Limit "OK"bfd

0.5³tftw

1.1³Úif

"Not Accceptable" otherwise

:= Limit "OK"=

Fa 112

Lr1Cc×æ

çè

ö÷ø

2×-

éêêë

ùúúû

Q Fy×

FS×

éêêë

ùúúû

Lr

Cc£if

p2 E×

Lr

æçè

ö÷ø

2 1223æçè

ö÷ø

×

otherwise

:= Fa 12.392 ksi×=

Pa Fa A×:= Pa 197.035 kip×=

ALLOWABLE STRENGTH ACCORDING TO JUNE!22, 2010 EDITION

BUCKLING ABOUT X-AXIS

Fexp2 E×

Lrx

æçè

ö÷ø

2:= Fxcr 0.658

Q Fy×

Fex Q× Fy×

æççè

ö÷÷ø

Q Fy×

Fex2.25£if

0.877 Fex×( ) otherwise

:= Fxcr 25.395 ksi×=

BUCKLING ABOUT Y-AXIS

Feyp2 E×

Lry

æçè

ö÷ø

2:= Fycr 0.658

Q Fy×

Fey Q× Fy×

æççè

ö÷÷ø

Q Fy×

Fey2.25£if

0.877 Fey×( ) otherwise

:= Fycr 21.037 ksi×=

TORSIONAL BUCKLING

G 11200ksi:= J 2.49in4:= ro 6.31in:= FzcrG J×

A ro2×

:= Fzcr 44.052 ksi×=

TORSIONAL FLEXURAL BUCKLING

H 0.668:=

FtfcrFycr Fzcr+

2 H×

æçè

ö÷ø1 1

4 Fycr× Fzcr× H×

Fycr Fzcr+( )2--

éêêë

ùúúû

×:= Ftfcr 17.314 ksi×=

Fcr min Fxcr Ftfcr, ( ):= Fcr 17.314 ksi×= FaFcr1.67

:= Fa 10.368 ksi×=

Pa Fa A×:= Pa 164.848 kip×=

ALLOWABLE STRENGTH IF TORSIONAL-FLEXURAL BUCKLING IS IGNORED:

Fa1min Fxcr Fycr, ( )

1.67:= Fa1 12.597 ksi×=

Pa1 Fa1 A×:= Pa1 200.289 kip×=

ALLOWABLE STRENGTH IF Q=1 & TORSIONAL-FLEXURAL BUCKLING IS CONSIDERED

Fxcr 0.658

FyFex Fy×

æççè

ö÷÷ø

FyFex

2.25£if

0.877 Fex×( ) otherwise

:= Fycr 0.658

FyFey Fy×

æççè

ö÷÷ø

FyFey

2.25£if

0.877 Fey×( ) otherwise

:=

FtfcrFycr Fzcr+

2 H×

æçè

ö÷ø1 1

4 Fycr× Fzcr× H×

Fycr Fzcr+( )2--

éêêë

ùúúû

×:=

Fcr min Fxcr Ftfcr, ( ):= Fcr 23.304 ksi×= Fa2Fcr1.67

:= Fa2 13.955 ksi×=

Pa2 A Fa2×:= Pa2 221.88 kip×=

ALLOWABLE STRENGTH ACCORDING TO JULY 7 2016 EDITION

Cw 17.3in6:= Fex 223.062 ksi×= Fey 46.877 ksi×=

Fezp2 E× Cw×

L2G J×+

æççè

ö÷÷ø

1

A ro2×

×:= Fez 44.329 ksi×=

FetfFey Fez+

H

æçè

ö÷ø1 1

4 Fey× Fez× H×

Fey Fez+( )2--

éêêë

ùúúû

×:= Fetf 57.803 ksi×=

Fe min Fex Fetf, ( ):= Fe 57.803 ksi×=

Fcr 0.658

FyFe Fy×

æççè

ö÷÷ø

FyFe

2.25£if

0.877 Fe×( ) otherwise

:= Fcr 34.812 ksi×=Fcr1.67

20.846 ksi×=

SECTION E7

c2 1.49:=c1 0.22:= dr 0.75 tw×EFy

×:=

Felc2 dr×

d

æçè

ö÷ø

2

Fy×:= Fel 48.452 ksi×=

EFFECTIVE WIDTH

be d d drFyFcr

×£if

d 1 c1FelFcr

×-æççè

ö÷÷ø

×FelFcr

×éêêë

ùúúûotherwise

:=

be 13.016 in×=

EFFECTIVE AREA

Aeff in2×=AeffAeff A d be-( ) tw×-:=

Pcr kip×=PcrPcr Fcr Aeff×:=

Pa 164.848 kip×=PaPcr1.67

:=

SUMMARY:

ASD ALLOWABLE STRENGTH ACCORDING TO THE 1963, 1969 2010 AND 2016 EDITIONS OFTHE AISC SPECIFICATION FOR A 14 FT HIGH WT 15X54 COLUMN OF 50 KSI STEEL:

1963: 272 KIP 1969: 197 KIP2010: 165 KIP2010, IGNORING TFB 200 KIP :2010 Q=1: 222 KIP2016: 310 KIP

STRUCTURAL DESIGN WITH ALUMINUM ALLOY MEMBERS

TED GALAMBOSFebruary 27,2018

2018 STRUCTURAL ENGINEERING SEMINAR SERIES

COLLEGE OF PROFESSONAL EDUCATION

MORE TO BE LEARNED THAN CAN BE PRESENTED HERE

ASCE SEMINARS ON DEMAND , FALL 2017 AND WINTER 2018:ALUMINUM STRUCTURAL DESIGN WITH THE 2010 ALUMINUM DESIGN MANUAL.

J.R. KISSELL, R.L. FERRY “ALUMINUM STRUCTURES” JOHN WILEY,1995

M.L, SHARP, “BEHAVIOR AND DESIGN OF ALUMINUM STRUCTURES”, McGRAW-HILL, 1993

F.M. MAZZOLANI, “ALUMINUM ALLOY STRUCTURES”, PITMAN ADVANCED PUBLISHING PROGRAM, BOSTON, 1985

DESIGN SPECIFICATIONS• SPECIFICATION FOR ALUMINUM STRUCTURES,

ALUMINUM ASSOCIATION, PART OF A LARGE TOME OF THE ALUMINUM DESIGN MANUAL

• EUROCODE 9• CSA S157 (CANADA)• BS8118 (UK)• AS 1669 (AUSTRALIA)

MY ALUMINUM CREDENTIALS

• DEVELOPMENT OF LOAD AND RESISTANCE FACTOR (LRFD) METHOD ADOPTED BY THE SPECIFICATION OF THE ALUMINUM ASSOCIATION (1979)

• TAUGHT A SHORT COURSE ON DESIGN WITH ALUMINUM ALLOYS AT SYDNEY UNIVERSITY IN 1993.

SOME HISTORYLATIN “ALLUME”: MATERIAL OF DUBIOUS COMPOSITION, MENTIONED ALREADY BY THE

EGYPTIANs IN THE 17TH CENTURY BC.

1827: WHOELER OBTAINED FIRST ALUMINUM NUGGET IN GERMANY

1886: P. T. T. HEROULT (IN FRANCE) AND C. M. HALL (USA) INDEPENDENTLY INVENTED

AN ELECTROLYTIC PROCESS FROM WHICH THENINDUSTRIAL PRODUCTION OF

ALUMINUM BEGAN.

IN THE USA HALL’S INVENTION LED TO THE BIRTH OF THE

ALUMINUM COMPANY OF AMERICA (ALCOA)

INTERESTING COINCIDENCE: HEROULT AND HALL WERE BORN IN THE SAME YEAR,

STUDIED THE SAME SUBJECT, ACHIEVED EQUIVALENT RESULTS,

PROMOTED EQUIVALENT TECHNOLOGICAL INNOVATIONS, AND DIED IN THE

SAME YEAR (1863-1914)

ADVANTAGES• LIGHT WEIGTH (ABOUT 1/3 OF STEEL)• CORROSION RESISTANCE (FORMS HARD

PROTECTIVE LAYER, HEALS WELL)• SMOOTH SURFACE FOR PAINTING• EASE OF FABRICATION: MANY SHAPES• NON-MAGNETIC, NON-TOXIC• HIGH THERMAL AND ELECTRICAL CONDUCTIVITY• EASE OF DESIGNING ALLOYS FOR APPLICATIONS• EASE OF RECYCLING

DISADVANTAGES• HIGH COST• MODULUS OF ELASTICITY IS 1/3 OF THAT OF STEEL• LOSS OF STRENGTH FROM WELDING OF HEAT-

TREATED ALLOYS IN THE VICINITY OF THE WELD BEAD

• GALVANIC CORROSION WHEN DISSIMILAR METALS ARE IN CONTACT: AN ALUMINUM PART BOLTED TO A STEEL STRUCTURE WITH MOISTURE ALLOWED IN THE FAYING SURFACE A NONO!

CROSS-SECTION CHOICES = INFINITE.EXAMPLE:

SHAPE USED IN POWER LINE TOWERS

Buckminster Fuller Geodesic DomeSt. Louis, MO, Shaw’s Garden

BAUXITEORE

BAYERPROCESS

PUREALUMINUM

OXIDE

Al3O3 DISSOLVED IN NaOH AT HIGHTEMPERATURE

ELECTROLYSIS

PUREALUMINUM

ALLOYING ANDTEMPERING

INGOTS FOR FORMING:ROLLING, EXTRUDING, FORGING, CASTING

PRODUCTION OF ALUMINUM

INGOTS

SERIES ALLOYING ELEMENTS

COMMENTS

1000 91% + ALUMINUM2000 COPPER STRENGTH THROUGH HEAT-TREATMENT,

LOW CORROSION RESISTANCE, USE IN AIRCRAFT

3000 MANGANESE NOT HEAT TREATABLE, USED IN SHEET METAL CONSTRUCTION

4000 SILICON USED FOR WELD FILLER METAL, LOW MELTING POINT

5000 MAGNESIUM NOT HEAT TREATABLE, USED IN SHEET METAL AND WELDED CONSTRUCTION

6000 MAGNESIUM & SILICON

BEST COMBINATION OF STRENGTH AND CORROSION RESISTANCE, 6061 IS POULAR FOR STRUCTURALAPPLICATIONS

7000 ZINC STRONGER THAN 6000 SERIES, BUT NOT AS CORROSION RESISTANT

ALUMINUM ASSOCIATION AND ALCOA CLASSIFICATION

FURTHER CLASSIFICATION OF ALLOYS

• NON-HEAT TREATABLE• ALLOYS 1000, 3000,

4000, 5000• SUFFIX “H”• TEMPER IS ATTAINED

BY COLD-WORKING

• HEAT TREATABLE• ALLOYS

2000,6000,7000• SUFFIX “T”• TEMPER PRODUCED BY

HEAT TREATING• T5-T10 HAS FURTHER

STRENGTHENING THROUGH “ARTIFICIAL AGING”

OTHER DISTINCTIONS• WROUGHT ALLOYS: SHEET AND PLATE, EXTRUSIONS

AND FORGINGS• CAST ALLOYS: HAVE A DIFFERENT SET OF AA/ALCOA

NUMBERING SYSTEM!• MILITARY SPECIFICATIONS ARE DIFFERENT FROM AA

SPECS• STRONG ALLOY TO USE FOR STRUCTURAL ENGINEERING

USES: 6061-T6 EXTRUSIONS. SOLUTION HEAT TREATED THEN ARTIFICIALLY AGED, MAJOR ALLOYING INGREDIENTS: MAGNESIUM AND SILICON

THINGS TO CONSIDER BEFORE CALCULATION• CHOICE OF STRUCTURAL MATERIAL SYSTEM:• ALUMINUM• COLD-FORMED STEEL• STAINLESS STEEL• CHOICE OF ALUMINUM ALLOY• CORROSION PROTECTION• STRENGTH• DEFLECTION• CHOICE OF CONNECTION• WELDING• BOLTS• RIVETS

APPLICABLE CIVILIAN ALUMINUM DESIGN SPECIFICATIONS IN THE USA• AASHTO: “BRIDGE DESIGN SPECIFICATIONS”• AASHTO: “STANDARD SPECIFICATIONS FOR

STRUCTURAL SUPPORTS, HIGHWAY SIGNS, LUMINARIES AND TRAFFIC SIGNALS”

• ALUMINUM ASSOCIATION: “SPECIFICATION FOR ALUMINUM STRUCTURES”

SPECIFICATION FOR ALUMINUM STRUCTURES(AA Specs)

• ADMINISTRATOR:• THE ALUMINUM ASOCIATION (AA)• 1400 CRYSTAL DRIVE, SUITE 4300, ARLINGTON, VA 22202• WWW.ALUMINUM.ORG• AUTHORS:• THE AA ENGINEERING AND DESIGN TASK FORCE• ENGINEERING ADVISORY COMMITTEE

• (TVG WAS MEMBER OF 2000 EDITION ADVISORY COMMITTEE, • KEN VALERIUS IS MEMBER OF 2015 EDITION COMMITTEE)

• PUBLISHED SINCE 1967• IN TVG POSSESSION: 1986 (5TH EDITION), 2000 (7TH EDITION), • 2015 (10TH EDITION)

SOME GENERAL COMMENTS ON AA SPEC• “COMPUTATION OF FORCES, MOMENTS,

STRESSES AND DEFLECTIONS SHALL BE IN ACCORDANCE WITH ACCEPTED METHODS OF ELASTIC STRUCTURAL ANALYSIS AND ENGINEERING DESIGN”

• THE BASIC DESIGN PARAMETERS ARE STRESSES• SIMPLIFIED AND SAFE FORMULAS ARE THE

BASIS OF DESIGN CHECKING, BUT MORE RIGOROUS ANALYSIS IS PERMITTED

ONE MORE GENERAL COMMENT• THE BASIC STRUCTURE AND CONTENT OF THE

AA SPECS IS THE WORK OF THE RESEARCH CONDUCTED IN THE ALCOA LABORATORY (J. W. CLARK, M. L. SHARP AND CO-WORKERS),

• AT BUCKNELL UNIVERSITY (R.J.BRUNBRABER), IOWA STATE UNIVERSITY (W. W. SANDERS), CORNELL UNIVERSITY (T. PEKOZ) AND

• LEHIGH UNIVERSITY (J. W. FISHER), • AMONG MANY OTHERS WORLD-WIDE

THE 2015 ALUMINUM DESIGN GUIDE

• SPECIFICATION FOR ALUMINUM STRUCTURES• COMMENTARY ON THE AA SPECS.• DESIGN GUIDE• MATERIAL PROPERTIES• SECTION PROPERTIES• DESIGN AIDS• ILLUSTRATIVE EXAMPLES• GUIDELINES FOR ALUMINUM SHEET METAL

WORK IN BUILDING CONSTRUCTION

EXTRUDED SHAPES LISTED IN AA MANUAL

• CHANNELS, 2-12 INCHES IN DEPTH• ANGLES, 1x1 TO 8X8 INCHES IN SIZE• TEES, UP TO 8 INCHES IN DEPTH• ZEES, UP TO 8 INCHES IN DEPTH• I-BEAMS, 2-5 INCHES IN DEPTH• CIRCULAR, SQUARE AND RECTANGULAR

TUBES• MANY OTHER EXTRUDED SHAPES

PROPERTY SYMBOL VALUEPOISSON’S RATIO n 0.33

MODULUS OF ELASTICITY E 10,100 KSI

SHEAR MODULUS OF ELASTICITY G 3,800 KSI

COEFFICIENT OF THERMAL EXPANSION a 13´10-6/°F

DENSITY g 0.1lb/in3

SHEAR YIELD STRENGTH Fsv 0.6Fty

SHEAR ULTIMATE STRENGTH Fsu 0.6Ftu

COMMON MATERIAL PROPERTIES

THE ALUMINUM ASSOCIATION SPECIFICATIONS,OF 2000

• TWO VERSIONS:• SPECIFICATIONS FOR ALUMINUM

STRUCTURES• PART A: ALLOWABLE STRESS DESIGN*• PART B: BUILDING LOAD AND RESISTANCE

FACTOR DESIGN**• * BUILDINGS AND BRIDGES• ** BUILDINGS ONLY

THE ALUMINUM ASSOCIATION SPECIFICATIONS OF 2000

• THE DESIGN EQUATIONS ARE DEFINED AS THE STRENGTH AT THE LIMIT IN BOTH PARTS

• LOAD EFFECTS IN PART A (ASD) ARE BASED ON WORKING LOADS, AND NOMINAL STRENGTHS ARE DIVIDED BY SAFETY FACTORS

• LOAD EFFECTS IN PART B (LRFD) ARE BASED ON FACTORED LOADS, AND THE NOMINAL STRENGTHS ARE MULTIPLIED BY RESISTANCE FACTORS.

FACTORS OF SAFETY IN ASD2000 edition

• BUILDINGS & OTHER STRUCTURES

• BRIDGES

u

y

a

n 2.20n 1.85n 1.35

==

=

u: ultimate or bucklingy: yieldinga: appearance of buckling

u

y

a

n 1.95n 1.65n 1.20

==

=

RESISTACE FACTORS f IN LRFD

• 0.95 FOR GENERAL YIELD• 0.85 FOR BEAMS• 0.85 FOR ELEMENTS OF BEAMS AND

COLUMNS• 0.95 TO 0.85 FOR COLUMNS, DEPENDING ON

THE SLENDERNESS RATIO• 0.8 FOR ELASTIC BUCKLING OF TUBES• 0.90 FOR WEB CRIPPLING

TABLE OF CONTENTS 2000 EDITION

• 1.GENERAL• DESIGN PROCEDURE• 3. GENERAL DESIGN RULES• 4. SPECIAL DESIGN RULES• 5. MECHANICAL CONNECTIONS• 6. FABRICATION• 7. WELDED CONSTRUCTION• 8. TESTING

ALL FURTGER PARTS OF THIS LECTURE WILL BE ON THE 2015 EDITION OF THE

AA SPECIFICATION

TABLE OF CONTENTS OF 2015 EDITION• A. GENERAL PROVISIONS• B. DESIGN REQUIREMENTS• C. DESIGN FOR STABILITY• D. DESIGN OF MEMBERS FOR TENSION• E. DESIGN OF MEMBERS FOR COMPRESSION• F. DESIGN OF MEMBERS FOR FLEXURE• G. DESIGN OF MEMBERS FOR SHEAR• H. DESUGN OF MEMBERS FOR COMBINED FORCES AND TORSION • J. DESIGN OF CONNECTIONS• L. DESIGN FOR SERVICEABILITY• M. FABRICATION AND ERECTION• N. QUALITY CONTROL AND QUALITY ASSURANCE• APPENDIX 1. TESTING• APPENDIX 3. DESIGN FOR FATIGUE• APPENDIX 4. DESIGN FOR FIRE CONDITIONS• APPENDIX 5. EVALUATION OF EXISTING STRUCTURES• APPENDIX 6. DESIGN OF BRACES FOR COLUMNS AND BEAMS• FOLLOWS AISC SPES FORSTEEL BUILDINGS!

LIMIT STATES TO CHECK

WHAT TO CONSIDER• YIELDING• RUPTURE• STABILITY• FATIGUE• CORROSION• FIRE• SERVICEABILITY

WHAT IS NEEDED• MATERIAL PROPEETIES• TABLES A.3.1 – a.3.8• & AA MANUAL PART IV

• CROSS SECTION PROPERTIES

• @ AA MANUAL PART V.

UNIFIED DESIGN CRITERIA IN 2015 EDITION

• LRFD: • ASD

u nF Ff£ naFFW

£

Fu= required strength using LRFD load combinations, ASCE7, Sec. 2.3

Fa= required strength using ASD load combinations, ASCE7, Sec. 2.4

Fn= nominal strength

LIMIT STATE F W W

RUPTURE, 0.75 1.95 2.20YIELDING, BUCKLING 0.90 1.65 1.85

BOLTS, RIVETS 0.65 2.34 2.64SCREWS 0.50 3.00 3.5

BUILDINGS BRIDGES

MATERIAL PROPERTIES

• THE FOLLOWING MATERIAL PROPERTIES ARE LISTED

IN TABLE A 3.3 OF THE 2015 AA SPECIFICATIONS:

• Ftu and Fty in tension

• Fcy = compression equals Fty

• Ftuw and Ftyw in the heataffected zone

• For 6062-T6 extrusions: Ftu=38 ksi and Fy= Fcy=35 ksi

STRESS-STRAIN CURVE

STRESS

STRAIN

Fy

Eo

0 0.001 0.002

s0.2

s0.1

OFFICIAL REPORTED VALUE

n

o y

02

01

0.002E F

ln2n

ln

s se

ss

æ ö= + ç ÷ç ÷

è ø

=æ öç ÷è ø

RAMBERG-OSGOOD s-e CURVE

n 1

o

y y

1

E1 0.002n

F F

ts

-=æ öæ ö

+ ç ÷ç ÷ç ÷ç ÷è øè ø

TANGENT MODULUS

on

2

2

E

kLF

r

tp=æ öç ÷è ø

COLUMN FORMULA

STRESS

STRAIN

Fy

Eo

0 0.001 0.002

s0.2

s0.1

STRESS

STRAIN

Fy

Eo

0 0.001 0.002

s0.2

s0.1 TANGENT MODULUS

0 2 4 6 8 100

0.5

1

1.5RAMBERG-OSGOOD STRESS-STRAIN CURVES

NON-DIMENSIONAL STRAIN

NO

N-D

IMEN

SIO

NAL

STR

ESS

s/sy

e/ey

n=5

n=20

6061-t6

cyF

B

1S 2S00L / r

ALLOYS ARTIFICIALLY AGED,T5,T6,T7,T8,T9

B D( L / r )-

( )

2

2E

L / rp

cF

l

SLENDERNESS PARAMETERS, b/t. l/rl

l1 l2

APPROXIMATION OF TANGENT MODULUS METHOD IN AA SPECS

cF

cyF

B

1S 2S00L / r

ALLOYS NOT ARTIFICIALLY AGED,O,H,T1,T2,T3,T4

SLOPE IS CONTINUOUS

B D( L / r )-( )

2

2E

L / rp

( )

2

2E

L / rp

0 0.5 1 1.5 20.2

0.4

0.6

0.8

1COLUMN CURVE, n=20

Non-dimensional Length

N0n

-dim

ensio

nal S

treng

th

cyF

B

1S 2S00L / r

ALLOYS ARTIFICIALLY AGED,T5,T6,T7,T8,T9

B D( L / r )-

( )

2

2E

L / rp

cF

TANGENT MODULUS

AA SPECS

NOTE:FORMULAS FOR B & D & CARE GIVEN IN TABLES B.4.2

0 0.5 1 1.5 20.2

0.4

0.6

0.8

1COLUMN CURVE, n=5

Non-dimensional Length

N0n

-dim

ensio

nal S

treng

th

cF

cyF

B

1S 2S00L / r

ALLOYS NOT ARTIFICIALLY AGED,O,H,T1,T2,T3,T4

SLOPE IS CONTINUOUS

B D( L / r )-( )

2

2E

L / rp

( )

2

2E

L / rp

TANGENT MODULUS

NOTE:FORMULAS FOR B & D & CARE GIVEN IN TABLES B.4.1

MEMBER DESIGN FOR STRENGTH • CHAPTER D” DESIGN OF MEMBERS FOR TENSION• RUPTURE• YIELDING• NET AREA• EFFECTIVE NET AREA

nt t

n u e

y

t

g

tPP

F AF A

=

=

MEMBER DESIGN FOR STRENGTH

• CHAPTER E: DESIGN OF MEMBERS FOR COMPRESSION

• YIELDING• FLEXURAL BUCKLING• TORSIONAL AND FLEXURAL-TORSIONAL

BUCKLING• LOCAL BUCKLING à GO TO CHAPTER B

( )

P F Anc c g

F for cy 1

CcF B D 0.85 0.15 for c c c 1 2Cc 120.85 E

for > 22

l l

ll l l l

l

pl l

l

=

ì üï ï£ï ïï ï

æ öé ù-ï ïï ïç ÷ê ú= - + < £í ýç ÷-ê úï ïë ûè øï ïï ïï ïï ïî þ

c cy1 2 c

c

B F C

Dl l

-= =

aa

DEFINITION OF l

e

e

kLl arg est

2EF

F elastic torsional or flexural-torsional buckling

l

l p

=

=

=

BUCKLING CONSTANTS B, D, & C• THESE ARE EMPIRICAL FORMULAS THAT APPROXIMATE THE TANGENT

MODULUS METHOD, AND THEY ARE STRONGLY SUPPORTED BY EXTENSIVE TESTS.

• THEY ARE ONLY DEPENDENT OF THE YIELD STRENGTH AND THE MODULUS OF ELASTICITY

• DIFFERENT CONSTANTS ARE GIVEN FOR COLUMNS, BEAMS AND CROSS SECTION ELEMENTS

• TABLE B.4.1 APPLIES TO NON-HEAT-TREATBLE ALLOYS AND WELD AFFECTED ZONES (O,H,T1 – T4)

• TABLE B.4.2 APPLIES TO HEAT-TRETABLE ALLOYS (T5-T9)

cyc cy

c cc

cc

c

FB F 1

2250ksi

B BD10 E0.41BCD

é ù= +ê ú

ê úë û

=

=

cy

c

c

c

F 35ksi

E 10,100ksiB 39.4ksiD 0.246ksiC 65.7

=

==

=

=

FOR 6061-T6 ALLOY

MEMBER DESIGN FOR STRENGTH

• CHAPTER F: DESIGN OF MEMBERS FOR FLEXURE

• PLASTIC MOMENT• RUPTURE• LATERAL-TORSIONAL BUCKLING• LOCAL BUCKLING à GO TO CHAPTER B• SHEAR STRENGTH AND SHEAR BUCKLING à

GO TO CHAPTER G

( )np cy t ty cy

2xc

np c3c c

n2

xcc2

M min ZF 1.5S F ,1.5F

E SM 1 if C

C CM

ES if >C

p lll

pl

l

=

ì üæ ö- + £ï ïç ÷

ï ïè ø= í ýï ïï ïî þ

y 2bye w b

xye b

IL r C 0.038JL

Sr Cl = = +

LOCAL BUCKLING CHECK• SECTION B.5 “ELEMENTS”• ELEMENTS SUPPORTED ON ONE EDGE

• ELEMENTS SUPPORTED ON BOTH EDGES

• EDGE STIFFENED ELEMENTS

• ELEMENTS WITH AN EDGE STIFFENER

COMBINATION OF BUCKLING COEFFICIENTS

FLAT ELEMENTS

CURVED ELEMENTS

UNIFORM COMPRESSION

FLEXURAL COMPRESSION

Bp, Dp, Cp

Btb, Dtb, Ctb

B t, D t,

C t

Bbr , D

br , Cbr

NOTE:CAREFUL READING OF THIS SECTION BEFORE USE IS STRONGLY RECOMMENDED

sy 1w

s sy ss s s 1 2 1 2

w w s

2

22

n

w

w

s w

hF if t

B F Ch hF B -1.25D if < ; t t 1.25D 1.25

E h if > t1.25h

t

V F ht

l

l l l l

pl

ì üï ïï ï£ï ïï ïï ï -æ öï ï= £ = =í ýç ÷

è øï ïï ïï ï

=

ï ïæ öï ïç ÷ï ïè øî þ

G. DESIGN OF MEMBERS FOR SHEARG.2 MEMBERS WITH FLAT WEBS

SUPPORTED ON BOTH EDGES

H. DESIGN OF MEMBERS FOR COMBINED FORCES AND TORSION

INTERACTION EQUATION

ryrxr

c cx cy

MMP1

P M M+ + £

ADDITIONAL COMMENTS ON THE 2015 AA SPECS

• CAREFUL STUDY OF THE SPECIFICATION AND THE KISSEL-FERRY BOOK IS HIGHLY RECOMMENDED IF YOU ARE NEW TO ALUMINUM STRUCTURAL DESIGN!

• THE TRICKIEST PART IN THE WHOLE PROCESS IS THE DESIGN OF A MEMBER FABRICATED FROM PLATES BY WELDING!

COMMENTS ON CHAPTER C:DESIGN FOR STABILITY

• CONSIDER IN THE ANALYSIS:

• AXIAL, FLEXURAL AND SHEAR DEFORMATIONS

• SECOND ORDER EFFECTS, PD &Pd

• GEOMETRIC IMPERFECTION:

• “tolerances specified in the contract document”

• “the displacements shall be placed to cause the greatest destabilizing effect”

• Stiffness to be 85% 0f elastic stiffness

• Elastic stiffness to be reduced by a tangent modulus that was derived for steel structures!

EFFECT OF WELDING ALLOYS THAT ATTAIN STRENGTH BY BY HEAT TREATMENT: T5 – T9

• LOSS OF STRENGTH IN THE HEAT-AFFECTED ZONES

• For 6065-T6 PLATES: • Ftu=Fcu=42 ksi à Ftuw=Fcuw=24ksi • Fty=Fcy=35ksi à Ftyw=Fcyw=15ksi

TYPE OF WELD & HEAT AFFECTED ZONES

• TRANSVERSE WELD: AN ENTIRE CROSS SECTION ALONG THE MEMBER IS WELDED

nt ty

no

nw

TENSION MEMBER : P F A

COMPRESSION MEMBER : P if weld is within 0.05L of endP otherwise

=

TYPE OF WELD & HEAT AFFECTED ZONES

• LONGITUDINAL WELD:PART OF A CROSS SECTION IS AFFECTED

• THE AA SPECS USE “WEIGHTED AVERAGE METHOD”

tf

bf

tw

d

1"1"

1"HEAT AFFECTED ZONES

LONGITUDINAL FILLETWELDS

wz wzc co cw

g g

A AF F 1 F

A A

æ ö æ ö= - +ç ÷ ç ÷ç ÷ ç ÷

è ø è ø

CHAPTER J: DESIGN OF CONNECTIONS• GENERAL PROVISIONS• WELDS• BOLTS• RIVETS• TAPPING SCREWS• PINS• AFFECTED ELEMENTS OF MEMBERS AND CONNECTIONS• BEARING STRENGTH OF FLAT SURFACES• FLANGES AND WEBS WITH CONCENTRATED FORCES• ROOFING AND SIDING CONNECTIONS

COMMENTS ON CONNECTION CHAPTER• FASTENERS AND WELDS IN ONE CONNECTION ARE PROHIBITED• SLIP-CRITICAL BOLTED CONNECTIONS ARE INCLUDED• SHEAR STRENGTH OF FILLET WELDS: 0.6 (0.85Ftuw)• THE APPROPRIATE COMBINATION OF WELD FILLER METAL AND

WROUGHT ALLOYS IS PROVIDED IN TABLE M.9.1 FOR WROUGHT ALLOYS• FOR EXAMPLE: 6061ALLOY BASE METAL IS PAIRED WITH 5356 WELD

FILLER.• CHAPTER m: “FABRICATION AND ERECTION” ALSO CONTAINS

INSTRUCTIONS ON THE CONTACT OF ALUMINUMWITH DISSIMILAR MATERIALS: STEEL, STAINLESS STEEL, WOOD, FIBERBOARD ANDN OTHER POROUS MATERIALS.

• Paint it!

SERVICEABILITY, CHAPTER L

• WHEN THE SERVICEABILITY LOAD EFFECT EXCEEDS THE ELASTIC LOCAL BUCKLING STRENGTH, THEN A CROSS SECTION WITH AN EFFECTIVE WIDTH MUST BE USED IN CALCULATING THE DEFLECTION!

APPENDICES• 1. TESTING: • 2 METHODS ARE GIVEN • METHOD 1: Rn= Rtest-average-Ks• METHOD 2: COMPUTE f AND W WITH FIRST-ORDER

PROBABILITY FORMULA

• 3. DESIGN FOR FATIGUE • CONSTANT AMPLITUDE AND VARIABLE AMPLITUDE

USING MINER’S RULE

END OF ALUMINUM LECTURE

ALUMINUM DESIGN #1A DESIGN A CHANNEL COLUMN BY 2015 AA SPEC

TVG 009/19/201

CALCULATE THENOMINAL ALLOWABLE STRENGTH OF AN ALUMINUM COLUMN.TYPE OF STRUCTURE: BUILDINGMETHOD OF DESIGN: LRFDMATERIAL: 6061-T6 ALUMINUM ALLOYLENGTH: 10 FTMEMBER DESIGNATION: CS 12 X 8.27 AA STANDARD CHANNEL (TABLE 4) SEC. E2 IN ALUMINUM ASSOCIATION 2015 DESIGN SPECIICATION

Fcy 35ksi:= bf 4.00in:= A 7.04in2:= L 10ft:= xo 2.45in:=

E 10100ksi:= tf 0.47in:= rx 4.77 in:= Cw 281in6:=

d 12in:= ry 1.25in:= lLry

:= J 0.367in4:= '

tw 0.29in:= R 0.4in:=l 96=

FLEXURAL BUCKLING ABOUT Y-AXIS

FROM TABLE B.4.2, BUCKLING CONSTANTS, FOR TEMPER DESIGNATIONS BEGINNING WITH T5 - T9

Bc Fcy 1Fcy

2250ksi+

æçè

ö÷ø

×:= DcBc10

BcE

×:= Cc 0.41BcDc×:=

Bc 39.365 ksi×= Dc 0.246 ksi×= Cc 65.673= l 2 Cc:=

f c 0.9:= l 1Bc Fcy-

Dc:= l 1 17.762=

Fc Fcy l l 1£if

Bc Dc l×-( ) 8.85 0.15Cc l-( )Cc l 1-

×+éêë

ùúû

×éêë

ùúû

l 1 l< l 2£if

0.85 p2

× E×

l2

otherwise

:=

Fc 9.194 ksi×=

fP nc f c Fc× A×:=

fP nc 58.252 kip×=

CHECK LOCAL BUCKLING OF FLANGE SEC> B.5.4.1

k1 0.35:= k2 2.27:= b bf tw- R-:=btf

7.043=b 3.31 in×=

Bp Fcy 1Fcy

1500 ksi×

æçè

ö÷ø

13

+

éêêêë

ùúúúû

×:= Bp 45.001 ksi×= DpBp10

BpE

×:= Dp 0.3 ksi×=

Cp 0.41BpDp×:= Cp 61.423=

l pf1Bp Fcy-

5 Dp×:= l pf2

k1 Bp×

5 Dp×:=

l pf1 6.659= l pf2 10.487=

Fpfc Fcybtf

l pf1£if

Bp 5 Dp×btf×-æ

çè

ö÷ø

l pf1btf

< l pf2£if

k2 Bp E××

5 btf×

otherwise

:=

Fpfc 34.424 ksi×=

fP nfc f c Fpfc× A×:=

fP nfc 218.11 kip×=

CHECK LOCAL BUCLING STRENGTH OF WEB, sEC. B.5.4.2

bw d 2 tf R+( )×-:= bw 10.26 in×=bwtw

35.379=

l pw1Bp Fcy-

1.6 Dp×:= l pw2

k1 Bp×

1.6 Dp×:=

l pw1 20.81= l pw2 32.771=

Fpwc Fcybwtw

l pw1£if

Bp 1.6 Dp×bwtw×-

æçè

ö÷ø

l pw1bwtw

< l pw2£if

k2 Bp E××

1.6bwtw×

otherwise

:=Fpwc 27.035 ksi×=

fP nwc f c Fpwc× A×:=

fP nwc 171.295 kip×=

fP nc 58.252kip= fP nfc 218.11kip= fP nwc 171.295kip=

fP n min fP nc fP nfc, fP nwc, ( ):= fP n 58.252 kip×=

0 50 100 150 2000

0.2

0.4

0.6

0.8

1COLUMN CURVE FOR 6061-T6 COLUMNS

L/r

Fc.

Fcy

0 5 10 15 200

0.2

0.4

0.6

0.8

LOCAL BUCKLING OF FLANGE

b/t

Fc/

Fcy

0 20 40 60 800

0.2

0.4

0.6

0.8

LoCAL BUCKLING OF WEB

h/t

Fc.Fc

y

ALUMINUM DESIGN #2 BY 2016 AA SPECCHECK A ZEE COLUMN

TVG 09/25/2017

x

y

z

d

b

t

FROM AA MANUAL: Z4.00X3- 1/16X2.85; 6061-T6 EXTRUSION

d 4.0in:= E 10100ksi:=b 3.062in:= Fcy 35ksi:=t 0.25in:= Ftu 38ksi:=A 2.42in2:=

G 3800ksi:=Ix 6.31in4:=

L 5ft:=Iy 4.01in4:=

rz 0.668in:=

Lrz

89.82= Iz A rz2×:= Iu Ix Iy+ Iz-:= ro

Iz Iu+

A:=

Iz 1.08 in4×= Iu 9.24 in4×= ro 2.065 in×=

From p.52 of TVG "Structural Members and Frames":

a'b 0.5 t×-( ) t×

2 2 b 0.5 t×-( )× t× d t-( ) t×+[ ]×:=

a' 0.153=

Cw124 b 0.5 t×-( )3 d t-( )2× t×éë ùû× 1

6 a'× d t-( )×b 0.5 t×-

+éêë

ùúû

:= Cw 8.049 in6×=

J13 2 b 0.5 t×-( )× d t-( )+[ ]× t 3×:= J 0.05 in4×=

From Table B,4.2in the AA Specification:

Bc Fcy 1Fcy

2250 ksi×+

æçè

ö÷ø

×:= DcBc10

BcE

×:= Cc 0.41BcDc×:=

Bc 39.365 ksi×= Dc 0.246 ksi×= Cc 65.673=

l 2 Cc:=f c 0.9:= l 1

Bc Fcy-

Dc:=

l 1 17.762=

lLrz

:= l 89.82=BUCKLING ABOUT Z-AXIS:

Fc Fcy l l 1£if

Bc Dc l×-( ) 0.85Cc l-

Cc l 1-+

æçè

ö÷ø

×éêë

ùúû

l 1 l< l 2£if

0.85 p2× E×

l2

otherwise

:=

Fc 10.502 ksi×=

fP nz f c Fc× A×:= fP nz 22.874 kip×=

TORSIONAL BUCKLING, EQ. E.2.4 IN AA NLRFD SPECIFICATION

Fet1

A ro2×G J×

p2 E× Cw×

L2+

æççè

ö÷÷ø

×:= Fet 40.054 ksi×= l pEFet

×:= l 49.887=

Fc Fcy l l 1£if

Bc Dc l×-( ) 0.85Cc l-

Cc l 1-+

æçè

ö÷ø

×éêë

ùúû

l 1 l< l 2£if

0.85 p2× E×

l2

otherwise

:=

Fc 31.97 ksi×=

fP nT f c Fc× A×:= fP nT 69.631 kip×=

fP n min fP nz fP nT, ( ):= fP n 22.874 kip×=

ALUMINUM DESIGN #3ADESIGN A WIDE-FLANGE BEAM USING AA 2015 SPECIFICATION

TVG 09/25/2017

CALCULATE THE AVAILABLED STRENGTH OF AN ALUMINUM WIDE-FLANGE BEAMTYPE OF STRUCTURE: BUILDINGMETHOD OF DESIGN: LRFDMATERIAL: 6061-T6 ALUMINUM ALLOYSPAN:10FTMEMBER DESIGNATION: I 12X11.7 TtABLE 8, AA STANDARD I BEAMSCHAPTER F IN 2 015 AA SPECIFICATIONAPPLIED LOAD: A CONCENTRATED LOAD AT THE CENTER OF THE BEAMBENDUNG IS ABOUT X-AXIS. THE LOSAD ACTS AT THE CENTROID OF THE W-SECTION

Fcy 35ksi:= bf 7.0in:= A 9.92in2:= Ix 256in4:= L 10ft:=

E 10100ksi:= tf 0.47in:= rx 5.07in:= Sx 42.6in3:= Cw 894in6:=

G 3800ksi:= d 12in:= ry 1.65in:= Iy 26.9in4:= J 0.621in4:='

Ftu 38ksi:= tw 0.29in:= R 0.400in:= Zx 46.8in3:=

FROM TABLE B.4.2, FORMULAS FOR BUCKLINH CONSTANTS, FOR ALLOYS WITH TEMPERS T5 - T9

Bc Fcy 1Fcy2250ksi

+æçè

ö÷ø

×:= DcBc10

BcE

×:= Cc 0.41BcDc×:=

Bc 39.365 ksi×= Dc 0.246 ksi×= Cc 65.673=

CHECK FLEXURAL STRENGTH OF GROSS SECTION

CASE 1: THE BEAM IS FULLY BRACED AGAINST LATERAL-TORSIONAL BUCKLIN G

LIMIT STATE: YIELDING

f b 0.9:= Mnp min Zx Fcy× 1.5 Sx× Fcy×, ( ):= Mnp 1.638 103´ in kip××=

fM np f b Mnp×:= fM np 1.474 103´ in kip××=

LIMIT STATE RUPTURE

f r 0.7:= k1 0.5:= TABLE B.4.3 fM nrf r Zx× Ftu×

k1:=

fM nr 2.49 103´ in kip××=

CASE 2 : THE BEAM IS LATERALLY BRACED AT THE CENTER, UNDER THE LOAD

Cb12.5

2.5 0.75+ 2+ 2.25+:= Cb 1.667= Lb

L2

:=

ryeIySx

Cw 0.038 J× Lb2×+×:= rye 1.952 in×=

l

Lb

rye Cb×:= l 23.812=

Mnmb Mnp 1l

Cc-æ

çè

ö÷ø

× p2 E× l×

Sx

Cc3

×+éêêë

ùúúû

l Cc£if

p2 E× Sx×

l2

otherwise

:=Mnmb 1.401 103´ in kip××=

fM nmb f b Mnmb×:=

fM nmb 1.261 103´ in kip××=

CHECK LOCAL BUCKLING STRENGTH OF FLANGE, SEC. B.5.4.1FROM TABLE B.4.2

k2 2.04:=k1 0.5:= Bp Fcy 1Fcy

1500 ksi×

æçè

ö÷ø

13

+

éêêêë

ùúúúû

×:= DpBp10

BpE

×:=

Cp 0.41BpDp×:= b

bf tw-

2R-:=

btf

6.287=

Cp 61.423=Bp 45.001 ksi×= Dp 0.3 ksi×=

l 1Bp Fcy-

5 Dp×:= l 2

k1 Bp×

5 Dp×:= l 2 14.981=

Fc Fcy( ) btf

l 1£if

Bp 5Dpbtf×- l 1

btf

< l 2£if

k2 Bp E××

5btf×

otherwise

:=

Fc 35 ksi×=

f b Fc× Sx× 1.342 103´ in kip××=

CHECK LOCAL BUCLING STRENGTH OF WEB, SEC. B.5.5.1

h d 2 tf×-:= h 11.06 in×=htw

38.138= m 0.65:=

Bbr 1.3 Fcy× 1Fcy340 ksi×

æçè

ö÷ø

13

+

éêêêë

ùúúúû

×:= DbrBbr20

6BbrE

×:= Cbr23

BbrDbr×:=

Dbr 0.666 ksi×= Cbr 66.92=Bbr 66.824 ksi×=

l 1Bbr 1.5 Fcy×-

m Dbr×:= l 1 33.103= l 2

k1 Bbr×

m Dp×:= l 2 171.125=

Fb 1.5 Fcy×( ) htw

l 1£if

Bbr m Dbr×htw×-æ

çè

ö÷ø

l 1htw

< l 2£if

k2 Bbr E××

mhtw×

otherwise

:=

Fb 50.322 ksi×=

f b Fb× Sx× 1.929 103´ in kip××=

0 50 100 150 2000

0.2

0.4

0.6

0.8

1BENDING STRENGTH OF BEAM

Lb/r.y

M/M

p

DESIGN OF A WELDED ALUMINUM WIDEFLANGEBEAM

TVG 10/17/2017DETERMINE THE AVAILABLE CAPACITY OF AN ALUMINUM BEAM TO SUPPORT A UNIFORMLY DISTRIBUTED LOAD w APPLIED DOWNWARD ON TOP OF THE TOP FLANGEOF THE I-BEAM DURING ERECTION. BENDING IS ABOUT THE X-AXIS.

tf

bf

tw

d

1"1"

1"HEAT AFFECTED ZONES

LONGITUDINAL FILLETWELDS

bf 16in:= 6061-T6 ALUMINUMALLOY PLATES

tf 1.0in:=

d 48in:=

tw 0.375in:=

CROSS SECTION PROPERTIES: AREA OF ONE FLANGE: Afo tf bf×:=

AREA OF HEAT-AFFECTED ZONE IN ONE FLANGE: Afw tf 2 1× in tw+( )×:=

AREA OF WEB: Awo tw d 2 tf×-( )×:=

AREA OF HEAT-AFFECTED ZONE IN THE WEB: Aww 2 1× in tw×:=

TOTAL AREA: A 2 Afo× Awo+:=

Afo 16 in2×= Afw 2.375 in2×= Awo 17.25 in2×= Aww 0.75 in2×= A 49.25 in2×=

Ix

2 tf3× bf×

122 Afo×

d tf-

2

æçè

ö÷ø

2

×+tw d 2 tf×-( )3×

12+:= Ix 2.072 104´ in4×=

Sx

Ix

0.5 d×:= Sx 863.184 in3×= Iy

2 tf× bf3×

12

d 2 tf×-( ) tw3×

12+:= ry

Iy

A:=

ry 3.724 in×= Iy 682.869 in4×= Cw

d tf-( )2 Iy×

4:= Cw 3.771 105´ in6×=

J1

32 bf× tf

3× d 2tf-( ) tw3×+é

ëùû×:= J 11.475 in4×=

Zx 2 Afo×d tf-( )

2×

tw d 2 tf×-( )2×

4+:= Zx 950.375 in3×=

Properties for the design of the fillet weld:

Filler alloy for the fillet weld is specified in Table M.9.1. of the AA Specificationfor the plate alloy 6061-T6: Alloy 5356.

Tabl2 A.3.6. provides Ftuw=35ksi for alloy 5356 for the fillet strength calculationFnw=0.6x0.85Ftuw in Table J.2.2.

Properties for the plate material:Table A.3.1. specifies that Fcy=Fty from Table A.3.3.

For Alloy 6061-T6, in the zone unaffected by the welds, Ftu=42ksi and Fcy=35ksi.For Alloy 6061-T6, in the zone affected by the welds, Ftuw=24ksi and Fcy=15ksi.

Ftuw 35ksi:= Fnw 0.6 0.85× Ftuw×:= Fnw 17.85 ksi×=

Ftu 42ksi:= Fcy 35ksi:= Fcyw 15ksi:= E 10100ksi:=

For the local buckling calculations we will need the followingbuckling constants Bp , Dp ,Cp, for flange local buckling, and Bbr ,Dbr ,Cbr for web local buckling, from Tables B.4.1. for theweld affected yield stress Fcyw, and from Tables B.4.2. for theweld unaffected yield stress Fcy.Following is a calculation ofthe required buckling coefficients from these tables:

k2br 2.04:= m 0.65:=k1p 0.35:= k2p 2.27:= k1br 0.5:=

Bp Fcy 1Fcy

1500ksi

æçè

ö÷ø

13

+

éêêêë

ùúúúû

×:= DpBp10

BpE

×:= Cp0.41 Bp×

Dp:=

Bpw Fcyw 1Fcyw440ksi

æçè

ö÷ø

13

+

éêêêë

ùúúúû

×:= DpwBpw20

6BpwE

×:= Cpw2 Bpw×

3Dpw:=

Bbr 1.3Fcy 1Fcy340ksi

æçè

ö÷ø

13

+

éêêêë

ùúúúû

×:= DbrBbr20

6 Bbr×

E×:= Cbr

2 Bbr×

3 Dbr×:=

Bbrw 1.3Fcyw 1Fcyw340ksi

æçè

ö÷ø

13

+

éêêêë

ùúúúû

×:= DbrwBbrw20

6 Bbrw×

E×:= Cbrw

2 Bbrw×

3 Dbrw×:=

Bp 45.001 ksi×= Bpw 19.864 ksi×= Bbr 66.824 ksi×= Bbrw 26.39 ksi×=

Dbrw 0.165 ksi×=Dpw 0.108 ksi×= Dbr 0.666 ksi×=Dp 0.3 ksi×=Cbr 66.92= Cbrw 106.488=Cpw 122.742=Cp 61.423=

Flange local buckling stress, Sec. B.5.4.1

a) Element unaffected by welding

Rf1Bp Fcy-

5 Dp×:= Rf2

Cp5

:=Rfbf tw-

2 tf×:=

Rf1 6.659= Rf2 12.285=Rf 7.813=

Fcf Fcy Rf Rf1£if

Bp 5 Dp× Rf×-( ) Rf1 Rf< Rf2£if

k2p Bp E××

5 Rf×otherwise

:= Fcf 33.268 ksi×=

b) Element affected by welding

Rf1wBpw Fcyw-

5 Dpw×:= Rf2w

Cpw5

:=

Rf1w 9.016= Rf2w 24.548=Rf 7.813=

Fcfw Fcyw Rf Rf1w£if

Bpw 5 Dpw× Rf×-( ) Rf1w Rf< Rf2w£if

k2p Bpw E××

5 Rf×otherwise

:= Fcfw 15 ksi×=

Web local buckling stress, Sec. B.5.4.1

a) Element unaffected by welding

Rw1Bbr 1.5Fcy-

m Dbr×:= Rw2

k1br Bbr×

m Dbr×:=Rw

d 2 tf×-

tw:=

Rw1 33.103= Rw2 77.216=Rw 122.667=

Fcw 1.5Fcy Rw Rw1£if

Bbr m Dbr× Rw×-( ) Rw1 Rw< Rw2£if

k2br Bbr E××

m Rw×otherwise

:= Fcw 21.019 ksi×=

b) Element affected by welding

Rw1wBbrw 1.5Fcyw-

m Dbrw×:= Rw2w

k1br Bbrw×

m Dbrw×:=

Rw1w 36.226= Rw2w 122.871=Rw 122.667=

Fcww 1.5Fcyw Rw Rw1w£if

Bbrw m Dbrw× Rw×-( ) Rw1w Rw< Rw2w£if

k2br Bbrw E××

m Rw×otherwise

:=

Fcww 13.217 ksi×=

a) Element unaffected by welding

Fcf 33.268 ksi×= Fcw 21.019 ksi×=

b) Element affected by welding

Fcfw 15 ksi×= Fcww 13.217 ksi×=

Weighted Average Local Buckling Stress of the Compression Flange

Fc Fcf 1AfwAfo

-æççè

ö÷÷ø

× FcfwAfwAfo

×+:= Fc 30.556 ksi×=

Weighted Average Local Buckling Stress of the Web

Fb Fcw 1AwwAwo

-æççè

ö÷÷ø

× FcwwAwwAwo

×+:= Fb 20.68 ksi×=

Weighted Average Method of moment at local buckling, Sec. F.3.1

If = moment of inertia of the flangesIw = moment of inertia of the webccf = distance from center of the cross section to the center of the flangeccw = distance from center of the cross section to the edge of the web

ccfd tf-

2:= ccw

d2

tf-:= If 2 Afo× ccf2×:= Iw

tw d 2 tf×-( )3×

12:=

If Iw+ 2.071 104´ in4×= Ix 2.072 104´ in4×=

Mnlb FcIf

ccf× Fb

Iwccw×+:= Mnlb 2.571 104´ in kip××=

Plastic moment: Mnp min Zx Fcy× 1.5 Sx× Fcy×, ( ):= Mnp 3.326 104´ in kip××=

Rupture: Mnu Zx Ftu×:= Mnu 3.992 104´ in kip××=

Lateral-Torsional buckling:

Bracing spacing: 10ftAssume Cb = 1.0 in Center of spanLoad is on top of top flange; use Eq. F.4-5

Lb 10ft:= Cb 1.0:=

ryeIySx

d-4

d2

16

CwIy

+0.038 J× Lb

2×

Iy++

æççè

ö÷÷ø

:= rye 3.394 in×=

IySx

Cw 0.038 J× Lb2×+× 4.33 in×=

RltbLb

rye Cb×:= Rltb 35.357=

Lateral-torsional buckling moments:

We need Cc buckling coefficient from Tables B.4..1 (with Fcyw for theweld-affected section), and B.4.2 (with Fcy for the unwelded material)

Bcw Fcyw 1Fcyw

1000 ksi×+

æçè

ö÷ø

×:= DcwBcw20

6BcwE

×:= Ccw2 Bcw×

3 Dcw×:=

Bc Fcy 1Fcy

2250 ksi×+

æçè

ö÷ø

×:= DcBc10

BcE

×:= Cc0.41 Bc×

Dc:=

Bcw 16.837 ksi×= Dcw 0.084 ksi×= Ccw 133.318=

Bc 39.365 ksi×= Dc 0.246 ksi×= Cc 65.673=

Member unaffected by welding:

Mnmbo Mnp 1RltbCc

-æççè

ö÷÷ø

×p

2 E× Sx× Rltb×

Cc3

+éêêë

ùúúû

Rltb Cc£if

p2 E× Sx×

Rltb2

otherwise

:=

Mnmbo 2.61 104´ in kip××=

Member affected by welding:

Mnpw min Zx Fcyw× 1.5 Sx× Fcyw×, ( ):= Mnpw 1.426 104´ in kip××=

Mnmbw Mnpw 1RltbCcw

-æççè

ö÷÷ø

×p

2 E× Sx× Rltb×

Ccw3

+éêêë

ùúúû

Rltb Ccw£if

p2 E× Sx×

Rltb2

otherwise

:=

Mnmbw 1.176 104´ in kip××=

Weighted average lateral-torsional bockling moment:

Weld affected area: Awz 2 in× tw+( ) tf× 1 in× tw×+:=

Area 2/3 farther from the neutral acxis: Af bf tf×d6

tf-æçè

ö÷ø

tw×+:=

Awz 2.75 in2×= Af 18.625 in2×=

Mnmb Mnmbo 1AwzAf

-æççè

ö÷÷ø

× MnmbwAwzAf

×+:= Mnmb 2.398 104´ in kip××=

Minimum available moment capacity for LRFD method"

PHIb 0.9:= PHIu 0.75:=

PHIMn min PHIb Mnlb× PHIu Mnu×, PHIb Mnp×, PHIb Mnmb×, ( ):=

PHIMn 2.158 104´ in kip××=

Lateral-torsional buckling controls

STRUCTURAL DESIGN WITH STAINLESS STEEL MEMBERS

TED GALAMBOSFEBRUARY 27, 2018

2018 STRUCTURAL ENGINEERING SEMINAR SERIESCOLLEGE OF PROFESSIONAL EDUCATION

UNIVERSITY OF MINNESOTA

STAINLESS STEEL

• WHAT IS IT?• A FAMILIY OF CORROSION AND HEAT

RESSITANT STEEL ALLOYS CONTAINING A MINIMUM OF ABOUT10% CHROMIUM

TYPES OF STAINLESS STEELFOR STRUCTURAL APPLICATIONS

• 1) AUSTENITIC: 17-18% CHROMIUM, 8-11% NICKEL

• 2) FERRITIC: 5-18% CHROMUIUM• 3) DUPLEX: 20-26% CHROMIUM, 1-8%

NICKEL, 0.05-5% MAGNESIUM, 0.05-0.3% NITROGEN

• MARTENSITIC: SURGICAL INSTRUMENTS, ETC.• PRECIPITATION HARDENING: HIGH STRENGTH

WHY CHOOSE STAINLESS STEEL?• #1 REASON: CORROSION PROTECTION IN

CORROSIVE ENVIRONMENTS à INDUSTRIAL, MARTIME, ETC.

• Other reasons:• Architectural, artistic, aesthetic• Seismic structures à high ductility• Structures in cold regions à not susceptible to

brittle fracture• High residual scrap value: Life-cycle cost

TYPES OF CORROSION

• PITTING CORROSION• CREVICE CORROSION• GALVANIC CORROSION (DISSIMILAR

MATERIALS)• STRESS CORROSION CRACKING

PITTING CORROSION

SAINT LOUIS ARCH

SCHUBERT CLUB BANDSCHELLSt. Paul, MN

STAINLESS STEEL=FRANK GEHRI

From New Yorker Magazine

THE CHICAGO BUBBLE

EADS BRIDGE St. LOUIS 1874

Cross section of chord

AIR FORCE ACADEMY CHAPEL

WHERE TO LEARN ABOUT STAINLESS

STEEL STRUCTURAL DESIGN

• “STRUCTURAL STAINLESS STEEL”

• AISC STEEL DESIGN GUIDE 27, 2013

• BY NANCY BADOO, ASSOCIATE DIRECTOR,

STEEL CONSTRUCTION INSTITUTE (UK)

• This guide also contains a complete set of

DESIGN RULES for flat-plate welded shapes,

rolled shapes and extruded shapes

OFFICIAL STRUCTURAL DESIGN SPECIFICATIONS

• COLD-FORMED MEMBERS:

• ROLLED, WELDED, HSS SECTIONS

USA ASCE 8-02 2002Australia/New Zealand AS-NZS 2001South Africa SABS 1997Japan SSBA 2005

EUROCODE CEN 2006A 2006Japan SSBA 1995

SPECIFICATION FOR CF STRUCTURES

• SEI/ASCE 8-02, (ASCE 8-90, 1st edition)• “SPECIFICATION FOR THE DESIGN OF COLD-

FORMED STAINLESS STEEL STRUCTURAL MEMBERS”

• Fashioned after the 1986 AISI Cold—Formed Steel Specification.

• Based on research by Wei-Wen Yu, Ravindra, Hsiao, Lin and Galambos

• LRFD format. ANSI approved

CONTENTS OF ASCE 8-02

• GENERAL PROVISIONS• ELEMENTS• MEMBERS• STRUCTURAL ASEMBLIES• CONNECTIONS AND JOINTS• TESTS

DESIGN REQUIREMENTS FOR HOT-ROLLED STAINLESS STEEL STRUCTURES• CHAPTERS 3-13 IN AISC DESIGN GUIDE 27

“STRUCTURAL STAINLESS STEEL”• BASED ON THE 2010 AISC SPECIFICATION• NOT AN ANSI APPROVED DOCUMENT

CONTENTS OF AISC SDG 27 • DESIGN REQUIREMENTS• DESIGN OF MEMBERS FOR TENSION,

COMPRESSION, FLEXURE, SHEAR, COMBINED FORCES.

• DESIGN OF CONNECTIONS• FIRE RESISTANCE• FATIGUE• FABRICATION AND ERECTION• TESTING

ASTM MATERIAL STANDARDS• THERE ARE MANY: FOR COLD-ROLLED SHEETS;

HOT-ROLLED PLATES, SHAPES, TUBES, PIPES; BOLTS; CASTINGS.

• MAIN REASONS FOR CHOICE: CORROSION RESISTANCE, TOUGHNESS, STRENGTH

• ASCE 8-02 LISTS 16 TYPES• TENSILE STRENGTH: 35-150 KSI• YIELD STRESS: 30-100 KSI• DUCTILITY (IN 2 INCH COUPON): 6%-40%

FOR ASTM UNS S30400, AISI 304, ANNEALED ALLOY

• TENSILE STRENGTH = 75 KSI

• YIELD STRESS = 30 KSI• ELONGATION = 40%

• INITIAL MODULUS OF ELASTICITY = 28,000 KSI

TYPE Fu Fy ELONGATION

Austenitic , S30400 75 ksi 30 ksi 40%

Duplex, S32304 87 ksi 58 ksi 25%

Precipitation hardening, S17400 135-190 ksi 105-170 ksi 16-10%

AS STRENGTH GOES UP, DUCTILITY GOES DOWN

STRESS-STRAIN CURVE

STRESS

STRAIN

Fy

Eo

0 0.001 0.002

s0.2

s0.1

OFFICIAL REPORTED VALUE

STRESS

STRAIN

Fy

Eo

0 0.001 0.002

s0.2

s0.1 TANGENT MODULUS

SECANT MODULUS

n

o y

02

01

0.002E F

ln2n

ln

s se

ss

æ ö= + ç ÷ç ÷

è ø

=æ öç ÷è ø

RAMBERG-OSGOOD s-e CURVE

n 1

o

y y

1

E1 0.002n

F F

ts

-=æ öæ ö

+ ç ÷ç ÷ç ÷ç ÷è øè ø

TANGENT MODULUS

on

2

2

E

kLF

r

tp=æ öç ÷è ø

COLUMN FORMULA

STRESS

STRAIN

Fy

Eo

0 0.001 0.002

s0.2

s0.1

VARIETIES OF EFFECTIVE CROSS SECTION IN SEI/ASCE 8-02

• EFFECTIVE CROSS SECTION FOR:• STRENGTH DETERMINATION AT FACTORED LOADS• DEFLECTION DETERMINATION• APPEARNCE AT SERVICE LOADS• 1) NO VISIBLE BUCKLES PERMITTED• 2) SMALL BARELY PERCEPTIBLE

LOCAL DISTORTION PERMITTED

SEI/ASCE 8-02 effective width procedure, Sec. 2.2

0

1.052 w ft Ek0.221

l

lrl

æ ö= ç ÷è ø

-=

0.643?

l £effb w=

effb wr=

k: elastic local bucklingcoefficient. k=4 for stiffenedk=o.5 for unstiffeneduniformly compressedflat element

f: stress calculated from the elasticaxial strength or bending strengthof the full unreduced section

BEAM DESIGN IN SEI/ASCE 8-02

LIMIT STATES

AT SERVICE LOADS AT FACTORED LOADSLOCAL DISTORTION

SMALL NONE

DESIGN STRENGTH

YIELDING LATERAL-TORSIONALBUCKLING

LOCALBUCKLING

ALSO TO BE CONSIDERED: SHEAR STRENGTHWEB CRIPPLING STRENGTHCOMBINATION OF BENDING AND SHEARCOMBONATION OF BENDING AND WEB CRIPPLING

BEAM DESIGN: LIMIT STATE YIELDINGMETHOD 1

n e y

e y

b

b

M S F

S : elastic section modulus computed with f=F

0.90 for X-section with stiffened flanges0.85 for X-section with unstiffened flanges

ff

=

=

=

METHOD 2: FORGET IT!

BEAM DESIGN, LIMIT STATE LTB

cn c

f

c

f

cc

f

2 t cc o b 2

o b

MM S

S

M : critical LTB momentS : S of full unreduced X-section

MS : S of effective section calculated at a stress

S

E dIM E C for I shape

E Lp

æ ö= ç ÷ç ÷

è ø

æ öæ ö= ç ÷ç ÷

è øè ø

ADDITIONAL BEAM-DESIGN RULES

• LTB SINGLY-SYMMETRIC, POINT SYMMETRIC, UNSYMMERTIC SHAPES

• STRENGTH FOR SHEAR ONLY• STRENGTH FOR COMBINED BENDING AND

SHEAR• CRIPPILING STRENGTH• COMBINED BENDING AND WEB CRIPPLING

STRENGTH.

COLUMN DESIGN EXAMPLE

c

n e n2

tn 2

0.85P A F

EFkLr

f

p

=

=

=æ öç ÷è ø

STAINLES STEEL COLUMN DESIGNC-Section

SEI/ASCE 8-02 SpecificationTed Galambos, 08/08/2013

Cross section: Simple cold-formedC-sectionWall thickness=tFlanges (unstiffened elements)=BWeb (stiffened element)=BCorner radii=R

Section properties of full section (from AISI Handbook):

B 1.25in:= A 0.722in2

:= J 0.00121in4

:=

D 8in:= Ix 5.44in4:= Cw 0.854in6:=

t 0.071in:= rx 2.75in:= ro 3.4in:=

R 0.1875in:= Iy 0.0695in4:=

ry 0.31in:=

Flat widths of elements

R' Rt2

+:=

wflange Bt2

- R'-:= wweb D t- 2 R'×-:=

wflange 0.992 in×= wweb 7.483 in×=

Material properties:Fy 28ksi:=

Eo 28000ksi:=

Go 10800ksi:=

Buckling about y-axis of C. This is the minor axis.

L 31in:=Lry

100=

From Table B, for Longitudinal compression and annealed type 201, 301 304, 316:

n 4.1:=Equation 3.4.1-1:

Guess value: FnFy2

:=

Fcr root Fnp2

Lry

æçè

ö÷ø

2

Eo Fy×

Fy 0.002 n× Eo×FnFy

æçè

ö÷ø

n 1-

×+

×- Fn, éêêêêë

ùúúúúû

:=

Fcr 14.05 ksi×=

Effective area (Sec. 2.2.1 and 2.3.1):

For the flanges: k 0.5:= l flange1.052

k

wflanget

æçè

ö÷ø

×FcrEo

×:=

l flange 0.465=

r flange 1 l flange 0.673£if

10.22

l flange-

l flangeotherwise

:= r flange 1=

For the web: k 4:= lweb1.052

k

wwebt

æçè

ö÷ø

×FcrEo

×:=

lweb 1.242=

rweb 1 lweb 0.673£if

10.22lweb

-

lwebotherwise

:= rweb 0.663=

Aeff A t wflange 1 r flange-( )× 2× wweb 1 rweb-( )×+éë ùû×-:=

Aeff 0.543 in2×=

Pn Aeff Fcr×:= Pn 7.625 kip×=

SOME CAUTIONARY REMARKS• INCREASE OF YIELD STRESS AT BENDS: TMW• EFFECTIVE CROSS SECTIONS IN FLEXURE:

TMW• INCREASE OF NOMINAL BENDING MOMENT

INTO THE PLASTIC RANGE ( METHOD 2): TMW

• IGNORE INELASTIC FACTOR IN LOCAL BUCKLING FORMULAS AT WORKING LOADS

• TMW=TOO MUCH WORK!

MORE REMARKS ON THE ASCE CF SPECS:

• BASED ON RESEARCH PERFORMED AT CORNELL IN THE 1960’S (AL JOHNSON, WINTER, W.-W YU.)

• CODE DEVELOPMENT RESEARCH AT ROLLA BY W.W. YU, AND RAVINDRA, TVG, AND OTHERS IN THE 1970-S.

• A NEW SPEC. IS IN EXISTENCE ( CHAIR KIM RASMUSSEN).

• ASCE HAS LOST INTEREST.

AISC STEEL DESIGN GUIDE 27STRUCTURAL STAINLESS STEEL

• COPYWRIGHT AND DATE: AISC, 1983• INTENDED TO BE USED WITH THE 2010 AISC

SPECS! • OK TO USE WITH 2016 SPECS, EXCEPT BE

CAREFUL WITH Q-FACTORS VERSUS EFFECTIVE AREAS FOR SLENDER UNSTIFFENED ELEMENTS!

• NOT ANSI APPROVED! Check with approving authority!

AISC STEEL DESIGN GUIDE 27

• CHAPTER 2: MATERIALS:PROPERTIES, SELECTION, AND DURABILITY

• EXCELLENT DESCRIPTION OF STAINLESS STEEL• I CANNOT RECALL A BETTER INTRODUCTION

TO A BEGINNER!

AISC STEEL DESIGN GUIDE 27• APPENDIX A: THE CONTINUOUS STRENGTH

METHOD. • YOU REALLY CAN SKIP THIS.• APPENDIX B: COMMENTARY TO THE DESIGN

RULES• MOST OF THIS RELATES TO THE STATISTICS OF

THE DEVELOPMENT OF THE RESITANCE FACTORS: SAVE IT FOR A RAINY SUNDAY AFTERNOON IN SEPTEMBER

AISC STEEL DESIGN GUIDE 27• DESIGN EXAMPLES ARE VERY. VERY HELPFUL!!• THE IMPORTANT PART FOR THE DESIGNER ARE• CHAPTERS 3 THROUGH 13!• THESE CHAPTERS GIVE THE NECESSARY

DIFFERENCES THAT PERTAIN TO STAINLESS STEEL FLAT PLATE STRUCTURAL ELEMNTS BEFORE SENDING YOU BACK TO THE AISC HOT-ROLLED SPEC.

AISC STEEL DESIGN GUIDE 27

• CHAPTERS THAT ARE OF ESPECIAL IMPORTANCE, AND DIFFERENT FROM THE AISC SPEC:

• CHAPTER 10: FIRE RESISTANCE• CHAPTER 13: TESTING

END OF STAINLESS STEEL LECTURE