easec13 presentation

BEHAVIOR AND STRENGTH OF COLD-FORMED STEEL

LIPPED CHANNEL SECTION WITH TRACK UNDER

COMPRESSION

WATANAPONG

HIRANMARN

PRAKIT PREMTHAMAKORN

PRAKIT CHOMCHUEN

NUTHAPORN

NUTTAYASAKUL

MAHANAKORN UNIVERSITY OF TECHNOLOGY, THAILAND

OUTLINE

INTRODUCTION

Load-Bearing Wall System

OBJECTIVE

SCOPE

EXPERIMENTAL INVESTIGATION

FINITE ELEMENT ANALYSIS

CONCLUSION


INTRODUCTION Load-Bearing Wall System

s


OBJECTIVE

The main objective is to present the compressivebehavior of stud-track from experimental investigation

and Finite Element Analysis (FEA)


SCOPE

Compression tests were conducted on 19 specimens for300mm and 800mm length cold-formed steel C-sectioncolumns with stud and stud-track

Finite Element Analysis (FEA) was conducted for 300mmlength stud specimens

The Ultimate experimental compressive strengths of thestuds are compared with the design strengths calculated(AISI 2007)


EXPERIMENTAL INVESTIGATIONo Test Specimens

(a) Stud Specimens (b) Stud-TrackSpecimens



H

B

D

t

r

H

B

t

r

o Section Dimensions

•Stud: 100x50x20x1.6mm

•tact,aver = 1.43mm

•Track: 105x50x1.6mm

•tact,aver = 1.53mm



o Material Properties (JIS Z 2241-1998)

Coupon fy (MPa) fu (MPa) E (MPa) Elogation (%)

Stud 292.25 358.68 218,385 40.6

Track 280.64 345.82 190,426 39.4



o Initial Geometric Imperfection

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

0 50 100 150 200 250 300Im

pe

rfac

tio

n (

mm

. )

Length ( mm. )

A

B_Left

B_Mid

B_Right

C

1 217f ,max

. mm 1 775w ,max

. mm

w

fl

fr


A

B

C


o Test Rig and Gauge Arrangement

Ten transducers were installed to record the displacements of the specimen under the

progressive increase in the axial compression, one for vertical and night for horizontal direction


EXPERIMENTAL INVESTIGATIONo Stud Test Results ( L= 300mm)

Specimen Pu

(kN)

Failure

modes

C300-1 62.98 L

C300-2

C300-3

C300-4

C300-5

C300-6

61.70

44.46

62.05

49.93

42.96

L

L

L

L

L

Average 54.010

5

10

15

20

25

30

35

40

45

50

55

60

65

70

0 1 2 3 4 5 6 7 8 9 10 11 12

Lo

ad

( k

N.

)

Displacement ( mm. )

C300-1 (Pu=62.98) C300-2 (Pu=61.70) C300-3 (Pu=44.46)

C300-4 (Pu=62.05) C300-5 (Pu=49.93) C300-6 (Pu=42.96)

Local

buckling

Max.

Min.

31.8% of

max.



o Stud Test Results ( Typical failure of C300-2)

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

5.5

6

6.5

7

0 1 2 3 4 5 6 7 8 9 10 11 12

Load

( T

on

. )




o Stud Test Results ( Typical failure of C300-2)



o Stud Test Results ( C300-3 specimen)


0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

5.5

6

6.5

7

0 1 2 3 4 5 6 7 8 9 10 11 12

Load

( T

on

. )



o Stud Test Results ( C300-3 specimen)


EXPERIMENTAL INVESTIGATIONo Stud Test Results ( L= 800mm)

Specimen Pu

(kN)

Failure

modes

C800-1

C800-2

C800-3

52.40

52.44

47.43

L

L

L

Average 50.76

Local

buckling


0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

0 1 2 3 4 5 6 7 8 9 10 11 12

Load

( k

N )


C800-1 (Pu=52.40) C800-2 (Pu=52.44) C800-3 (Pu=47.43)

Average C300 54.01Less than C300

about 6%


o Stud Test Results (Final failure shape of all C800 specimens)


EXPERIMENTAL INVESTIGATIONo Stud-Track Test Results ( L= 300mm)Specimen Pu

(kN)

Failure

modes

CT300-1 66.68 L

CT300-2

CT300-3

CT300-4

CT300-5

CT300-6

CT300-7

65.46

60.36

58.70

69.19

66.68

66.86

L

L

L+D

L

L

L

Average 64.85


0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

0 1 2 3 4 5 6 7 8 9 10 11 12

Lo

ad

( k

N.

)


CT300-1 (Pu=66.68) CT300-2 (Pu=65.46) CT300-3 (Pu=60.36)

CT300-4 (Pu=58.70) CT300-5 (Pu=69.19) CT300-6 (Pu=66.68)

CT300-7 (Pu=66.86)Average C300 54.01

More than C300

about 20%



o Stud-Track Test Results (Typical final failure shape of CT300-6 and -7)

EXPERIMENTAL INVESTIGATIONo Stud-Track Test Results ( L= 800mm)


0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

0 1 2 3 4 5 6 7 8 9 10 11 12

Lo

ad

( k

N.

)


CT300-1 (Pu=66.68) CT300-2 (Pu=65.46) CT300-3 (Pu=60.36)

CT300-4 (Pu=58.70) CT300-5 (Pu=69.19) CT300-6 (Pu=66.68)

CT300-7 (Pu=66.86)

Specimen Pu

(kN)

Failure

modes

CT800-1

CT800-2

CT800-3

62.23

63.18

67.92

L

L

L

Average 64.44

Local

buckling

Average C800 50.76More than C800

about 27%



o Stud-Track Test Results (Final failure shape of all CT800)

FINITE ELEMENT ANALYSISo Finite Element Model of Stud 300mm


•Stud : Shell Element (S4R)•Stud : Mesh size5x5 mm •Plate : Analytical rigid•Friction Coef. = 0.3•BC : Top Pl. move down only•BC : Bottom Pl is fixed.•Non-Linear Static Analysis, General

ABAQUS/CAE v. 6.11

0

50

100

150

200

250

300

350

400

450

0 0.02 0.04 0.06 0.08 0.1

Stre

ss (N

/sq

r.m

m)

Strain (mm/mm) True_Plastic

•Inclined section imperfection•Local imperfection



Section imperfection (Inclined section)o Finite Element Model of Stud C300-4

2-Planes



Section imperfection (Inclined section)o Finite Element Model of Stud C300-4



Local imperfection o Finite Element Model of Stud C300-4



o Finite Element Model of Stud C300-4

About 76% of AISI



o Finite Element Model of Stud C300-4

P = 0 kN P = 33.6 kN P = 61.0 kN (peak load) P = 24.2 kN Actual failure mode

CONCLUSIONo The results indicated that the ultimate compressive strength obtained from the

experiment results were only 56-82% of the estimated strength based on the Directstrength method (AISI 2007) at 76.7 kN

w


o The reduction of compressive strength indicates that just a little bit of inclinedsection imperfections may significantly reduce the ultimate strength of the shortstud

o The results of stud-track specimens indicate that the ultimate compressive strengthof stud can be increased and more consistency by connecting the studs with tracksat both ends

o The finite element model of 300mm length stud include inclined sectionimperfection indicate good agreement with the experiment results

easec13 presentation

Education

compressive behavior

length stud specimens

thailandintroduction

axial compression

strength of cold

seismic behavior of

main objective

design strengths