[雙語翻譯]外文翻譯--玻璃纖維增強(qiáng)尼龍66的力學(xué)性能研究實(shí)驗(yàn)研究（英文）

1、POLYMER TESTINGPolymer Testing 25 (2006) 544–552Material BehaviourA study of the mechanical behaviour of a glass fibre reinforced polyamide 6,6: Experimental investigationB. Mouhmida,?, A. Imada, N. Benseddiqa, S. Benmed

2、akhe ` neb, A. MaazouzcaLaboratoire de Me ´canique de Lille, CNRS UMR 8107, Ecole Polytech’Lille, Universite ´ de Lille1, Cite ´ Scientifique, Avenue Paul Langevin, 59 655 Villeneuve d’Ascq cedex, France b

3、AETech—Acoustic Emission Technology, 66, Av de Landshut, BP 50149, 60201 Compie `gne cedex, France cINSA de Lyon, Avenue Jean Capelle, 69621 Villeurbanne cedex, FranceReceived 30 January 2006; accepted 12 March 2006Abstr

4、actIn this experimental work, we studied the mechanical behaviour of a short glass fibre reinforced polyamide frequently used in the automobile industry. In order to investigate the influence of glass fibre content, temp

5、erature and strain rate, we carried out a series of uniaxial tensile loadings on an unfilled polyamide and glass fibre reinforced polyamide with different weight fractions: 15, 30 and 50 wt%. Experimental results showed

6、that the studied composite is a strain rate, temperature and fibre volume fraction dependant material. Both elastic modulus and tensile strength increase with strain rate and decrease with temperature. Glass fibre reinfo

7、rced PA66 exhibits improvement in its mechanical strength. The evolution of the normalized modulus and tensile strength as functions of relative density can be described by a type of power function. The acoustic emission

8、 (AE) technique, which is recognized as an effective tool for non-destructive testing and material evaluation, has been used to determine the damage threshold and obtain information about fracture mechanisms in the studi

9、ed composites. Scanning electron microscopy (SEM) analysis was made on the fracture surfaces to visualize the damage process: fibre fracture, matrix rupture and interface rupture. r 2006 Elsevier Ltd. All rights reserved

10、.Keywords: Polyamide 66; Glass fibres; Mechanical behaviour; Damage; Acoustic emission1. IntroductionGlass fibre reinforced polyamides continue to be used with increased frequency in many applications, such as stressed f

11、unctional automotive parts (fuelinjection rails, steering column switches) and safety parts in sports and leisure (snowboard bindings). These materials are known for their stiffness, toughness and resistance to dynamic f

12、atigue. Fibre reinforced thermoplastics compounds may be processed by conventional methods, such as injection moulding, and offer improvements in mechanical properties over unreinforced ones. These composites compete wit

13、h metals in manyARTICLE IN PRESSwww.elsevier.com/locate/polytest0142-9418/$ - see front matter r 2006 Elsevier Ltd. All rights reserved. doi:10.1016/j.polymertesting.2006.03.008?Corresponding author. Fax: +3 28 76 73 11.

14、 E-mail address: bouchaib.mouhmid@polytech-lille.fr (B. Mouhmid).clearly that the increase in fibre content leads to an increase in tensile strength and elastic modulus. In order to explain these evolutions, the elastic

15、modulus and the tensile strength can be modelled using a simple rearrangement of the rule of mixture equations: E ¼ avf Ef þ 1 ? vf ð Þ Em and sr ¼ bvf srf þ 1 ? vf ð Þ srm where E

16、f; srf are the modulus and the tensile strength of the fibre (Ef ¼ 76 GPa and srf ¼ 3200 MPa) and Em; srm are, respectively, the experimental values of the modulus and the tensile strength of the unreinforced P

17、A66, vf is the fibre volume fraction and a and b are the fibre orientation factors [8]. In our case, the average values of a and b are: a ¼ 0:24 and b ¼ 0:072, these values depend on the fibre length and orient

18、ation. The evolution of these two mechanical para- meters can also be modelled using a phenomen- ological description based upon the relative representations: normalized tensile strength sr=srm, normalized elastic modulu

19、s E=Em versus relative density r=r0 where r0 is the density of unreinforced PA66. Figs. 3 and 4 illustrate these evolutions and show that they are described by power relationships as follows:sr srm ¼ rr0? ?2:8 and E

20、Em ¼ rr0? ?3:7 ,with a good correlation coefficient: R2 ¼ 0:99 for both formulas. Imad [9] has suggested similarexpressions in a study about the mechanical behaviour of expanded polystyrene. This observation is

21、 in good agreement with literature data [10,11] and can be explained by the contribution of the glass fibre as a brittle and tough material. The loss of ductility is confirmed by theARTICLE IN PRESS120.00%50%30%15%180.01

22、60.0140.0100.080.060.040.020.00.0 0.0 5.0 10.0 15.0 20.0 25.0 30.0ε (%)σ (MPa)Fig. 2. Stress–strain curves with different glass fibre ratios at 20 1C and 5:6 ? 10?3 s?1.1ρ/ρ ρ/ρ01.5 1.4 1.3 1.2 1.12.802.602.402.202.001.8

23、01.601.401.201.00σr/σ /σr0y = 1x2.8R2 = 0.99Fig. 3. Variation of normalized tensile strength as a function of relative density.1ρ/ρ ρ/ρ0E /E04.003.503.002.502.001.501.001.1 1.2 1.3 1.4 1.5y = 1x3.7R2 = 0.99Fig. 4. Variat