High Performance Toughened Vinyl Ester Resins · single-edge-notch bending (SENB ) K 1c and G 1c ... Flexural Summary • CSRVE rebounds back to original position after testing •

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A novel approach to reduce fatigue cycling damage, impact resistance, and crack propagation in composite structures

High Performance Toughened Vinyl Ester Resins


Critical Damage/Recovery Properties of Vinyl Ester Resin with Rubber Modifier

Need to:

• Retain strength in the presence of flaws/damages

• Be able to store and recover large strains in response to temperature

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100 East Cottage Avenue | Carpentersville, IL 60110 | www.pccrusa.com 3

Typical Graphical Representation of Glass Transition Range using DMA


• Standard vinyl ester • Core shell rubber modified vinyl ester • Low viscosity epoxy resin used in the wind

industry

Resins Chosen for Study


• Flexural properties (ASTM D790) • Tensile properties (ASTM D638) • Plane-strain fracture toughness (ASTM D5045)

single-edge-notch bending (SENB) K1c and G1c

Clear Cast Mechanical Properties


• Short beam shear (ASTM D2344) • Drop ball impact • Fatigue testing

Fiber Reinforced Mechanical Properties


Flexural Test ASTM D790 on CSRVE at Maximum Deflection


Heating above Resin Tg (130°C) - Coupon Original Shape Recovered after 3 Minutes


Damage Recovery to Show Flexural Strength Retention

0

2000

4000

6000

8000

10000

12000

14000

16000

18000

20000

0.00 0.10 0.20 0.30

Stress (psi)

Extension (in)

123[4]


Flexural Strength Retention Data

Flexural Peak Stress

Original Anneal 1 Anneal 2 Anneal 3

20,000

16,000

12,000

8,000

4,000

0

(psi) Flexural Modulus

Original Anneal 1 Anneal 2 Anneal 3

500,000

450,000

400,000

350,000

300,000

250,000

200,000

(psi)


Flexural Test – ISO 178-2010 (similar to ASTM D790)

• CSRVE – (135 MPa) Flexural no breaks - no permanent

deformation • Epoxy – (125 MPa) Flexural no breaks, light permanent

deformation

• Vinyl standard – (145 MPa) Bending - breaking • Polyester standard – (115 MPa) Bending - breaking/shattered


Typical Tensile Properties of the Various Base Resins

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

11000

12000

13000

0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14

Stress (psi)

Strain (in/in)

Epoxy 2 CSRVE 2

DCPD

Standard VE

Epoxy 1 CSRVE 1


Tensile Elongation


Damage Recovery after Tensile Testing (ASTM D638)

Control Coupon — has not been tested

Coupon was stressed before failure

Coupon annealed above the glass transition andrecovered


Typical Tensile Properties of the Various Base Resins Plane-Strain Fracture Toughness (ASTM D5045) (SENB) – G1c

• K1C is standing for critical stress intensity factor • G1C is standing for critical energy release rate


Plane-Strain Fracture Toughness (ASTM D5045) (SENB) – K1c and G1c

specimen: 60 mm x 12.8 mm x 3.2 mm pre-crack: 6 mm depth by blade-tapping head speed: 1mm/min.


Elongation Comparison With Fracture Toughness, K1C


Energy per unit area of crack surface or critical strain energy release rate, G1C, at fracture initiation.


Apparent Interlaminar Shear Strength – Short-Beam Shear ISO 14130: 1997 (similar to ASTM D2334)

• Resistance test wing delamination of laminated carbon UD 300 g/m2 12K, 6-ply thickness 2mm

CSRVE deformation at 120 Mpa – no breaks

Standard VE resin deformation at 90 MPa crack breaking interlaminate


Apparent Interlaminar Shear Strength – Short-Beam Shear ISO 14130: 1997 (similar to ASTM D2334)

• Resistance wing delamination of laminated carbon UD 300 g/m2 12K, 6-ply thickness 2mm

DGEBA epoxy resin with 828 hardener dioxide MTHPA strain 110 MPa - no breaks


CSRVE Unique Toughness Properties

1-Lb. Steel Ball Dropped from 2 Feet on Un-Reinforced Castings

Standard VE CSRVE

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CSRVE Recovered

CSRVE Heat Treated and Recovered from Damage CSRVE Heat Treated and Recovered from Damage

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Drop Ball Impact on 3 Ply’s of E-Glass Mat from 2 Feet Drop Ball Impact on 3 Plys of E-Glass Mat from 2 Feet

Standard VE DCPD

CSRVE 1 CSRVE 2

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Drop Ball Impact on 4 Plys of 3K Carbon Weave Fabric From 3 Feet

CSRVE 2 Structural Epoxy

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Drop Ball Impact on 3 Ply’s of E-Glass Mat from 2 Feet Drop Ball Impact on 4 Plys of 3K Carbon Weave Fabric From All Heights

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Drop Ball Impact on 4 Ply of 3K Carbon Weave

0

1

2

3

4

5

3 4 5 6

Height (ft)

Cra

ck

Le

ng

th (

in)

Epoxy

CSRVE

Drop Ball Impact

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Toughness and Resistance to Fatigue of the Control Resin and CSRVE


0

20

40

60

80

100

120

140

160

VE CSRVE 1 CSRVE 2 Epoxy 1 Epoxy 2

Tem

pera

ture

(C)

HD

T

HD

T

HD

T

HD

T

HD

T

Tg

Tg

Tg

Tg

Tg

HDT and DSC Tg Properties


HDT Coupon Recovery


Straight Coupon was Bent after Heating


Heat Treated CSRVE Flat Coupon Made into a Coil


Recovery of Original Shape after Heat Treatment


Application Trial – CSRVE Vacuum Infusion of Transportation Deck


Hammer Impact Test on High Performance Olefin Yarn Comingled with 3K Carbon Fiber Helmet – No puncture!


Light Weight Moldable Parts using CSRVE Resin, Olefin, Carbon, Olefin/Carbon Hybrid Fabric, & Styrofoam Beads


Flexural Summary

• CSRVE rebounds back to original position after testing

• Epoxy would bend but would not recover • VE fractured • CSRVE above Tg will go back to original

shape – the same sample retested retained 80% of the original strength


Tensile Summary

• Epoxy and standard VE were sensitive to defects and reduced elongation by half

• CSRVE samples were not sensitive to defects,

very little reduction in elongation


G1c and Fatigue Summary

• G1c – CSRVE had 10 times the toughness of the

epoxy and VE • Fatigue test

– Control Resin pultruded spring – 125K cycles to failure

– CSRVE pultruded spring – 1 million cycles – did not break


Short Beam Shear

• CSRVE and epoxy did not shear – they bent

• VE sheared

• CSRVE had 120 MPa shear strength with no break, and epoxy resin had 110 MPa shear strength with no break

• Overall CSRVE has very good adhesion to carbon fiber


Drop Ball Impact Summary

• CSRVE using CS E-glass had the least damage compared to VE laminate

• Carbon fiber laminates made with CSRVE had

better crack resistances compared to the epoxy laminates

• Carbon fiber laminate made with epoxy broke in

half at 6-foot drop whereas the CSRVE laminate did not


HDT and DSC Summary

• Coupons after HDT testing show that CSRVE coupon rebounds back to original shape under static load – epoxy and VE did not have enough to rebound

• DSC scans show that all resins evaluated were

fully cured


Thank you! Questions?

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Documents

High Performance Toughened Vinyl Ester Resins · single-edge-notch bending (SENB ) K 1c and G 1c ... Flexural Summary • CSRVE rebounds back to original position after testing •