International Journal of Scientific & Engineering Research, Volume 4, Issue 9, September-2013 178
ISSN 2229-5518
Effect of Fiber-Reinforced Type on the Dynamic
Behavior of Composite Plate
Dr. Ahmed N. Al-Khazaraji, Dr. Farag Mahel Mohammed, and Mustafa Baqir Hunain
Abstract— an experimental investigation had been done to demonstrate the effect of fiber-reinforced type on the dynamic behavior of composite plate. The composite plates are manufactured at (2, 4, and 6 layers), from unsaturated polyester as a matrix with the fiber at (30%) volume fraction. Three type of fibers reinforcement are used; i) E-glass woven roving, ii) E-glass mat chopped, and iii) carbon. The tensile strength and Charpy impact tests are used to evaluate the mechanical properties. In fatigue tests, the specimens are investigated to estimate the basic S-N Curve and deduced there relations. The plate was fixed from all sides. Two steel balls of 16g and 23g were freely dropped from height of 0.5 m. The dynamic response of the plate was measured using vibration data collector (TVC 200). The results showed that the mechanical properties and the endurance limits increased while the deflection decreased with using carbon fibers- reinforced in compare with using E-glass fibers-reinforced.
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IBER reinforced composite material are known by their higher strength / weight and stiffness / weight ratios than metals; therefore, they are used in numerous light weight engineering applications, particularly in aircraft design. How- ever, the impact loads of external objects are still a major con- cern for such laminates in comparison to similar metallic structure that can cause internal material damage. Typical im- pact scenarios in aircraft design range from a tool dropped on the laminate surface, over runway debris thrown up by tires or hail to bird strike during flight. In this study the dynamic response test, fatigue test and Charpy impact test are used to demonstrate the dynamic behavior of laminated composite material experimentally. In the literature there are many stud- ies concern with the impact load on the composite structure, Alpaydin and Turkmen [1], were investigated the dynamic behavior of sandwich panels subjected to the impact load ex- perimentally and numerically, they investigated the dynamic response of the panel by measuring strain on a particular loca- tion on the panel. Vogler, et al [2], reported that the dynamic behavior of a tungsten carbide filled epoxy composite under planner loading condition. Planar impact experiments were conducted to determine the shock and wave propagation characteristics of the material. Jaafer [3], studied the effects of fiber on damping behaviors of composite materials with vol- ume fraction (Vf=1%, 2% and 3%). It was concluded that the stiffness, natural frequency, vibration damping and damped
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• Dr. Ahmed N. Al-Khazaraji, Mechanical Engineering Department, Uni- versity of Technology, Baghdad, Iraq.
• Dr. Farag Mahel Mohammed, Electromechanically Engineering Depart- ment, University of Technology, Baghdad, Iraq.
E-mail: drfaragmahel@yahoo.com
• Mustafa Baqir Hunain, Mechanical Engineering Department, College of
Engineering, Babylon University, Babylon, Iraq.
E-mail: hnain99@yahoo.com.
period increased with the increases of volumefraction of rein- forcement material. Heimbs, et al [4], were studied (experi- mentally and numerically) the influence of a compressive pre- load on the low velocity impact behavior of a carbon fiber – reinforced composite plate (CFRP). They were developed modeling strategies for low velocity impact simulation of CFRP plate under compressive preload with LS – DYNA with emphasis on the laminate delimitation and preload modeling. Sinan [5], demonstrate the effect of filler on the dynamic be- havior of sandwich panel, and present that the deflection de- crease with the graphite filler increase up to 7.5%. The main objective of this study is to investigate, experimentally the effect of fiber on the behavior of composite laminate plate un- der dynamic load.
The materials used in this investigation are the fiber and un- saturated polyester of (1.4g/cm3) density as a matrix. The fi- bers, which are compatible to unsaturated polyester resin, were used as the reinforcement. The fibers are carbon, E-glass woven roving and E-glass mat chopped. All the composite laminated plates were manufactured by dry hand lay-up pro- cedure. The unsaturated polyester resin was mixed with the hardener in the ratio 100:2 by weight. The stacking procedure of fiber-polyester composites was constructed by placing the fiber ply one above the other with the resin mixed well to spread between the plies by using mould of (300×200×20) mm. This process was repeated with a constant volume fraction of (30%) [6]. The inside wall of the frame was covered by a nylon paper to prevent the adhesion between the mould and the specimen. A steel cover was applied to prevent any shrinkage and removing any air bubbles trapped under the reinforce- ment during the curing process. The curing process was com- pleted in 24 hours at room temperature. After complete solidi- fication of composite sheet specimen, the product laminate was left for 3 hours in oven at 70 ◦C in order to achieve a suffi- cient curing. The product is a composite plate of (300×200)
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International Journal of Scientific & Engineering Research, Volume 4, Issue 9, September-2013 179
ISSN 2229-5518
mm with (2, 4 and 6) layers. To produce the test samples re- quired, the plate was cut into the appropriate dimensions us- ing a tipped cutter.
The mechanical properties demonstrated by using the tensile strength test and Charpy impact test. The tensile test speci- mens are manufactured according to ASTM D3039 standards [7], as shown in Fig. 1. While the Charpy test specimens are manufactured according to ISO-179 [8]. The test results are listed in Tables 1 and 2.
Fatigue is the failure or decay of mechanical properties after repeated applications of cycle stress lower than ultimate ten- sile stress of material [9]. Using an alternating-bending fatigue testing machine shown in Fig. 2, which performed at stress ratio of (-1). The equation of power law regression trend is a typical for composite fatigue data [10]. The regression con- stants (a, & b) and the correlation coefficient (R2), that repre- sent the fatigue trends results are given in Table (3).
The composite plate of (200×200 mm) has been fixed from all sides using eight bolts and an accelerometer has been glued at the center of the sheet in the back side. A metal pipe is fixed by a suitable structure over the sheet. This structure was used as a guide to be able to drop the steel ball on the center of the plate from a height of 0.5 m. The structure setup is shown in Fig. 3. Spherical steel balls of 16g and 23g were freely dropped on the top side of the composite plate. The strain is digitized and transferred to the vibration data collector (TVC 200) de- vice. The data transferred to a computer by connect the (TVC
200) to it. The data was analyzed by utilizing MCM3 software program to represent the dynamic response (deflection and frequency) of the tested plates.
The mechanical properties test results are listed in tables (1&2). The results show that the mechanical properties im- proved with the layer increased. With using carbon fiber rein- forced the mechanical properties increased rather than that of using E-glass. At six layers composite plate, the modules of elasticity, tensile strength and toughness of carbon fiber are increase by 300%, 200% and 110% respectively rather than of using E-glass woven roving fibers. In fatigue tests, the speci- mens are investigated to estimate the basic S-N Curve (fatigue only).The results with the deduced relations for the effect of layers and fiber reinforced are shown in Figs. (4, 5, 6 and 7). The endurance limit for using E-glass mat chopped fiber rein- forced at 106 is 5, 10 and 35 Mpa for 2, 4, and 6 layers respec- tively. While the endurance limit for using carbon fiber rein- forced at 106 is 12, 19 and 54 Mpa for 2, 4, and 6 layers respec- tively. At 6-layers, the endurance limits of carbon fibers and E- glass woven roving fibers are increased by 50% and 28% ra- ther than of using E-glass mat chopped fiber reinforced as
shown in fig. 7. The deflection in z-direction was measured at the center on the back side of the plate. Figs. 8, 9 and 10 repre- sent the behavior of E-glass mat chopped, woven roving and carbon fibers laminated plates respectively with impact loads of (16 & 23 ) g. The results showed that the laminated plates have the same deflection behavior but differ in magnitude. The deflection increased as the impact load increased due to the momentum increased. In general the deflection of 6-layers plate was decreased by 11% in comparison to the 2-layers. The deflection of the carbon fibers and E-glass woven roving fibers are less than the deflection of E-glass mat chopped fibers by
12% and 6% respectively, as shown in figure 8. Due to have a
higher toughness than the E-glass mat chopped fibers plate.
The following conclusions can be drawn:
1. The mechanical properties of are greater than of using E-
glass fibers.
2. The endurance limits of using carbon fibers are increased
rather than of using E-glass fibers.
3. The deflection of 2-layers using carbon fibers increased
by 11% than that of 6-layers.
4. The deflection of the carbon fibers is less than the deflec-
tion of E-glass fibers.
[1] Namik K. Alpaydin and Halit S. Turkmen, “The Dynamic Response of the Sandwich Panel Subjected to the Impact Load”, IEEE Xplore,
2009, 176-180. (www.ivsl.org).
[2] T. J. Vogler, C. S. Alexander, J. L. Wise, and S. T. Montgomery, Jour- nal of Applied Physics, 2009, 107, 1-13.
[3] H. J. Jaafer, “Effects of Fibers on Damping Behavior of Composites Materials”, M.Sc. Thesis, University of Technology, Department of Applied Scinces, Iraq. 2010.
[4] S. Heimbs, S. Heller, P. Middendorf, “Simulation of Low Velocity Impact on Composite Plates with Compressive Preload”, Material II- Composites, 7. LS-DYNA Anwenderforum, Bamberg, 2008, 11-24. (www.ivsl.org).
[5] Sinan Zuhair, “Improvement of polymer matrix composite material
behavior using optimum additive percentage of graphite and alumi- num under low velocity impact”, MSc. Thesis, AL-Mustansiriya Uni- versity, Baghdad-Iraq, 2013.
[6] Geoff eckold, “Design and manufacture of composite structures”, Jaico publishing house, 1995.
[7] J. M. Hodgkinson, “Mechanical Testing of Advanced Fiber Compo- sites”, Wood head published limited, Cambridge, England, 2000.
[8] Dieter Urban and Koichi Takamura, “Polymer Dispersions and Their
Industrial Applications”, Wiley-VCH Verlag GmbH & Co. KGaA,
2002.
[9] V. Rajendran, “Materials since”, Tata McGraw-Hill Publishing lim- ited, chapter 21, 2004.
[10] D. Samborsky, “Fatigue of E-Glass Fiber Reinforced Composite mate- rials and Substructures”, MSc Thesis, Montana State univerity, Bo- zeman, Montana, 1999.
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International Journal of Scientific & Engineering Research, Volume 4, Issue 9, September-2013 180
ISSN 2229-5518
Table- 1: Tensile test results
No. of layers | E-glass (mat chopped) fibers | E-glass (woven roving) fibers | Carbon fibers | |||
No. of layers | E1 (Gpa) | σt (Mpa) | E1 (Gpa) | σt (Mpa) | E1 (Gpa) | σt (Mpa) |
2 | 2.215 | 85.09 | 4.410 | 132.90 | 11.602 | 302.198 |
4 | 3.125 | 93.50 | 5.157 | 160.57 | 19.186 | 486.731 |
6 | 3.289 | 96.15 | 6.163 | 174.66 | 25.851 | 654.84 |
Table- 2: Charpy Impact test results
No. of layers | E-glass (mat chopped) fibers | E-glass (woven roving) fibers | Carbon fibers |
No. of layers | K (MPa√m) | K (MPa√m) | K (MPa√m) |
2 | 20.802 | 28.57 | 55.313 |
4 | 25.874 | 34.678 | 67.254 |
6 | 31.873 | 38.416 | 83.507 |
Table-3: Regression parameters of fatigue data.
NO. of layers
E-glass chopped E-glass woven Carbon
a b R2 a b R2 a b R2
2 -0.22609 4.48446 0.947685 -0.123102 3.95514 0.98261 -0.116239 5.12588 0.994718
4 -0.178339 4.42729 0.986505 -0.114402 4.12329 0.986795 -0.0991045 5.07742 0.986169
6 -0.131254 4.11148 0.922938 -0.106179 4.31618 0.976405 -0.0965047 5.20172 0.993862
Fig. 1: Tensile test specimen (ASTM-D3039).
Fig. 2: Fatigue testing machine and specimen.
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24
E-glass chopped
22
2 layers
20 4 layers
6 layers
18
16
14
σ=-0.131254N4.11148
10
8 σ=-0.178339N4.42729
6
σ=-0.22609N4.48446
4
Fig. 3: The impact test setup.
2
0.0E+0 2.0E+5 4.0E+5 6.0E+5 8.0E+5 1.0E+6 1.2E+6
No. of cycles
Fig. 4: Experimental S-N curves for E-glass mat chopped fiber composite plates at different layers.
36
34 E-glass woven
32 2 layers
4 layers
30
6 layers
28
26
24
22
20
σ=-0.106179N4.31618
18
16
14 σ=-0.114402N4.12329
12
σ=-0.123102N3.95514
8
6
4
85
80 Carbon
2 layers
75 4 layers
6 layers
70
65
60
55
σ=-0.0965047N5.20172
45 σ=-0.0991045N5.07742
40
σ=-0.116239N5.12588
35
30
25
0.0E+0 2.0E+5 4.0E+5 6.0E+5 8.0E+5 1.0E+6 1.2E+6
No. of cycles
Fig. 5: Experimental S-N curves for E-glass woven roving fiber composite plates at different layers.
0.0E+0 2.0E+5 4.0E+5 6.0E+5 8.0E+5 1.0E+6 1.2E+6
No. of cycles
Fig. 6: Experimental S-N curves for carbon fiber composite plates at different layers.
85
80 6 layers
75 E-glass chopped
70 E-glass woven
65 carbon
60
55 σ=-0.0965047N5.20172
50
45
40
35
30
25
σ=-0.106179N4.31618
15 σ=-0.131254N4.11148
10
5
0
85
80 6 layers
75 E-glass chopped
70 E-glass woven
65 carbon
60
55 σ=-0.0965047N5.20172
50
45
40
35
30
25
σ=-0.106179N4.31618
15 σ=-0.131254N4.11148
10
5
0
0.0E+0 2.0E+5 4.0E+5 6.0E+5 8.0E+5 1.0E+6 1.2E+6
No. of cycles
Fig. 7: Effect of fiber type on the S-N curve of composite plates.
0.0E+0 2.0E+5 4.0E+5 6.0E+5 8.0E+5 1.0E+6 1.2E+6
No. of cycles
Fig. 8-a: Deflection behavior of E-glass mat chopped fiber com- posite plates at w=16g.
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ISSN 2229-5518
36
33
30
27
24
21
18
15
12
9
6
3
0
-3
-6
-9
-12
-15
-18
-21
-24
-27
E- glass chopped h = 0.5 m , w = 23 g
2 layers
4 layers
6 layers
0 30 60 90 120 150 180 210 240 270 300 330 360 390
Time (msec)
36
33
30
27
24
21
18
15
12
9
6
3
0
-3
-6
-9
-12
-15
-18
-21
-24
-27
E-glass woven h=0.5 m , w=16 g
2 layer
4 layer
6 layer
0 30 60 90 120 150 180 210 240 270 300 330 360 390
Fig. 8-b: Deflection behavior of E-glass mat chopped fiber com- posite plates at w=23g.
Fig. 9-a: Deflection behavior of E-glass woven roving fiber com- posite plates at w=16g.
36
33
30
27
24
21
18
15
12
9
6
3
0
-3
-6
-9
-12
-15
-18
E-glass woven h=0.5 m , w=23 g
2 layers
4 layers
6 layers
26
24
22
20
18
16
14
12
10
8
6
4
2
0
-2
-4
-6
-8
-10
-12
-14
-16
-18
Carbon
h=0.5 m , w=16 g
2 layers
4 layers
6 layers
-21
-24
-27
0 30 60 90 120 150 180 210 240 270 300 330 360 390
-20
0 30 60 90 120 150 180 210 240 270 300 330 360 390
Time (msec)
Fig. 9-b: Deflection behavior of E-glass woven roving fiber com- posite plates at w=23g.
Fig. 10-a: Deflection behavior of carbon fiber composite plates at w=16g.
30
27
24
21
18
15
12
9
6
3
0
-3
-6
-9
-12
-15
-18
-21
-24
Carbon
h=0.5 m , w=23 g
2 layers
4 layers
6 layers
0 30 60 90 120 150 180 210 240 270 300 330 360 390
Time (msec)
Fig. 10-b: Deflection behavior of carbon fiber composite plates at w=23g.
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