Failure strain, %

Part I 材料機械性質檢測

綱要:

„ 拉伸性質

„ 撓曲性質

A. 拉伸性質

„

1. 應力 (σ): F/A

_o

²

²

2. 應變 (ε): ∆L/L

_o

3. 初始 楊式模數(

E

4. 屈服應力: 0.2% 偏位(off-set)法.

ε σ /

=

E

A.拉伸性質

試片準備

萬能強力試驗機

Instron 5582

PEEK 試片

銅貼片(防止應力集中)

PEEK 試片

拉伸後之PEEK 試片

PEEK 試片(dog-bone shape)

試片夾持

延伸計(Extensometer)

架延伸計量測楊式模數

m f

f f

L V E V E

E = + ( 1 − )

利用ROM (rule of mixtures) 評估

f m f

f

m f

T E V E V

E E E

+

= −

) 1

(

m f

f f

L V σ V σ

σ = + ( 1 − ) ) 2

1

( π

σ

σ _T = _m − ^{V f}

E _L : 縱向彈性模數.

E _T : 橫向彈性模數.

σ _L : 縱向拉伸應力.

σ _T : 橫向拉伸應力.

V _f : 纖維強化相體積分率.

E _f : 纖維彈性模數.

E _m : 基材彈性模數.

σ _f : 纖維拉伸應力.

σ _m :基材拉伸應力.

20 25 30 35

0 2 4 6 8 10

15 nm SiO2 30 nm SiO2 30 nm Al2O3

H

mi cr oh ar dn es s

Nano particle content, %

微硬度及室溫拉伸性質

Micr ohardness, Hv

3.5 4 4.5 5 5.5

0 2 4 6 8 10

15 nm SiO2 30 nm SiO2 30 nm Al2O3

El as ti c m od ul us , G P a

Nano particle content, % (a)

Modulus, GPa

80 90 100 110 120

0 2 4 6 8 10

15 nm SiO2 30 nm SiO2 30 nm Al2O3

UTS, MP a

Nano particle content, % (b)

UTS, MPa

0 5 10 15

0 2 4 6 8 10

15 nm SiO2 30 nm SiO2 30 nm Al2O3

T en si le el on gat ion , %

Nano particle content, % (c)

Failur e strain, %

Cal _{C al} Cal Cal

Mg/CF/PEEK夾層複材室溫拉伸性質檢測(縱向)

1. ASTM standard E8M-89.

2. 應變速率: 4×10 ^-4 sec ^-1 . 3. 架延伸計.

4. 縱向及橫向檢測.

0.00 0.02 0.04 0.06 0.08

0 200 400 600 800 1000

UTS 932 MPa

(a)

Engineering stress, MPa

Engineering strain

0.00000 0.0002 0.0004 0.0006 0.0008 0.0010 25

50 75

(b)

74.6 GPa

Engineering stress, MPa

Engineering strain

Young's Modulus

(L): 最大抗拉強度(UTS) 932 MPa, 92% of ROM value.

多重破壞

(L): E 74.6 GPa, 90% of ROM value.

拉伸後之 Mg/CF/PEEK 夾層複材試片

室溫拉伸性質檢測(橫向)

0.000 0.01 0.02 0.03 0.04

50 100 150 200 250

UTS 188 MPa

(a)

Engineerin g stress, MPa

Engineering strain

0.00000 0.0002 0.0004 0.0006 0.0008 0.0010 5

10 15 20 25 30 35

(b)

30.8 GPa

Engineering stress, MPa

Engineering strain

Young's Modulus

(T): UTS 188 MPa.

100% of ROM value.

單調破壞.

(T): E 30.8 GPa.

99% of ROM value.

室溫拉伸性質檢測

與商用金屬結構材比較.

室溫拉伸性質檢測

與CARALL (2024Al/CF/epoxy) 夾層複材比較

室溫拉伸性質檢測

室溫拉伸性質檢測

0.000 0.002 0.004 0.006 0.008 0.010 0.012 0.0140 200

400 600 800 1000

(a)

Engineering stress, MPa

Engineering strain

100^oC UTS 910 MPa

0.010 0.015 0.020 0.025 0.030

0 20 40 60 80 100 120 140 160 180

(b)

Engineering stress, MPa

Engineering strain

T100^oC UTS 163 MPa

0.0000 0.002 0.004 0.006 0.008 0.010 200

400 600 800 1000

(a)

Engineering stress, MPa

Engineering strain

L150^oC UTS 877 MPa

0.000 0.005 0.010 0.015 0.020 0.025 0.030 0.035 0

20 40 60 80 100 120 140 160

(b)

Engineering stress, MPa

Engineering strain

T150^oC UTS 144 MPa

(L) 100 ^o C UTS 910MPa.

93% of ROM value.

(T) 100 ^o C UTS 163MPa.

100% of ROM value.

(L) 150 ^o C UTS 877MPa.

95% of ROM value.

(T) 150 ^o C UTS 144MPa.

100% of ROM value.

室溫拉伸性質檢測

1. UTS 在100 及 150 ^o C 縱向減 少不多.

2. 碳纖維在縱向拉伸時扮演極

重要的角色.

撓曲性質檢測

„ 檢測標準

ASTM or CNS

„ 材料

Mg/CF/PEEK 夾層複材

撓曲性質檢測

„

„ 跨距:材料厚度= 28:1.

„

„

„

„

„

d ZL

R = ² / 6

R =夾頭速度, mm/min, L =跨距, mm,

D = 材料厚度, mm, and

Z = 外層纖維之應變速率, mm/mm/min. Z 為 0.01.

據此，夾頭速度為3.6 mm/min.

撓曲性質檢測

撓曲應力

2 2

/

3 PL bd

f =

σ

σ=樑中點處外層纖維之撓曲應力, MPa.

P = 最大荷重

b = 量的寬度, mm. 在此為12.7 mm.

d = 樑的厚度,mm.

撓曲性質檢測

/ 2

6 Dd L

f =

ε

ε f

撓曲應變

.

外層之撓曲應變, mm/mm.

D= 樑中點之彎曲量, mm.

L= 跨距長度, mm.

撓曲性質檢測

0.000 0.005 0.010 0.015 0.020 0.025 0.030 0.035 0

200 400 600 800

1000

Flexural Stress at Break, 960 MPa

Flexural Stress, MPa

Flexural Strain

Results

撓曲應力

0.0000 0.0005 0.0010 0.0015 0.0020 0.0025 0.0030 0

20 40 60 80 100 120 140 160 180

54.6 GPa

Flexural Stress, MPa

Flexural Strain

Flexural Modulus

Results

撓曲模數

照片

室溫撓曲性質檢測

„ 撓曲性質檢測(三點彎曲試驗):

1. ASTM D 790- 02 σ _f = 3PL/2bd ² .

P 荷重, L 跨距, b 寬度, d 厚度.

ε _f = 6Dd/L ²

D 中點之最大彎曲.

2. Span-to-depth 比 28:1.

3. 應變速率0.01 min ^-1 .

室溫撓曲性質檢測

0.000 0.005 0.010 0.015 0.020 0.025 0.030 0.0350 200

400 600 800 1000

(a)

Flexural Stress 960 MPa

Flexural stress, MPa

Flexural strain

0.0000 0.0005 0.0010 0.0015 0.0020 0.0025 0.00300 20

40 60 80 100 120 140 160 180

(b)

54.6 GPa

Flexural stress MPa

Flexural strain

Flexural Modulus

0.00 0.02 0.04 0.06 0.08 0.10 0

50 100 150 200 250 300 350

(a)

Flexural stress, MPa

Flexural strain

Flexural Stress 318 MPa

0.00000 0.0005 0.0010 0.0015 0.0020 10

20 30 40 50 60 70 80

(b)

36.5 GPa

Flex ural stress, MPa

Flexural strain

Flexural Modulus

L

T

室溫撓曲性質檢測

Modulus (L): 128/54.6 = 2.3 UTS (L): 1750/960 = 1.82. CF 主宰.

Modulus (T): 10.5/36.5 = 0.3 UTS (T): 165/318 = 0.52. Mg 主宰.

Compare with E and UTS: Tensile 74.6/45 = 1.7 932/290 = 3.2

Flexural 54.6/45 = 1.2 960/ 290 = 3.3

Room temperature flexural test

⇓ ⇓

1.

2.

象.

1.

2.