Paper Titles
Characteristics of Complementary Plastic Energy Produced by Hysteresis Curves and Analyses of Microstructures in Fatigued Metals
p.513
Effects of Roller Working and Ion Nitriding on Fatigue Properties of Eutectoid Steel
p.519
Effect of Additional Shear Strain Layer on Microstructure and Tensile Strength of Fine Wire
p.525
EBSD-AFM Hybrid Analysis of Crack Initiation in Stainless Steel under Fatigue Loading
p.531
Effect of Mean Stress on Fatigue Strength of Short Glass Fiber Reinforced Polybuthyleneterephthalate
p.537
Effect of Plastic Working on Pulsating Fatigue Strength of Notched Specimen
p.543
Evaluation of Fracture Surface of 11/4Cr-1/2Mo Steel by Residual Magnetization Induced from Inverse-Magnetostrictive Effect
p.549
Techniques for Determining Mechanical Properties of Power-Law Materials by Instrumented Indentation Tests
p.555
Micro-Indentation of Metal Matrix Composite - An FEM Investigation
p.563

Effect of Mean Stress on Fatigue Strength of Short Glass Fiber Reinforced Polybuthyleneterephthalate

Article Preview

Abstract:

Tension-compression fatigue tests under various mean stress conditions were conducted with round bar specimens of short glass fiber reinforced polybuthyleneterephthalate made by injection molding. Under cyclic loading with high mean stresses, the creep phenomenon became predominant and the ratcheting deformation increased with the number of cycles. This phenomenon is characteristic of plastics including short glass fiber reinforced plastics. The experimental data of the fatigue strength at the stress ratios above 0.7 were lower than the prediction based on the modified Goodman diagram. We propose to use the creep rupture strength, σc, instead of the tensile strength, σB, as the strength without mean stress and the parabolic equation for a constant life in the amplitude-mean stress (σa-σm) diagram. Our new design equation for the mean-stress effect on the fatigue strength on plastics is as follows: σa = σw – (σw / σc 2) σm 2, where σw is the fatigue strength at the stress ratio R=-1 and σa is the stress amplitude under a mean stress of σm. We also proposed a method to obtain the constant-life relation from limited experimental data.

You might also be interested in these eBooks
Engineering Plasticity and Its Applications View Preview

Info:

Periodical:

Key Engineering Materials (Volumes 340-341)

Pages:

537-542

DOI:

https://doi.org/10.4028/www.scientific.net/KEM.340-341.537

Citation:

Cite this paper

Online since:

June 2007

Authors:

Hideki Oka, Ryoichi Narita, Yoshiaki Akiniwa, Keisuke Tanaka

Keywords:

Creep Strength, Fatigue Strength, Glass Fiber, Injection Molding, Mean-Stress Effect, PBT, Plastic, Polybuthyleneterephthalate, Ratcheting Deformation, Stress Ratio

Export:

RIS, BibTeX

Price:

Permissions CCC:

Request Permissions

Permissions PLS:

Request Permissions

Сopyright:

© 2007 Trans Tech Publications Ltd. All Rights Reserved

Share:

Citation:

References

[1] M. Hojo, K. Tanaka and G.C. Gustafson, Effect of stress ratio on near threshold propagation of delamination fatigue cracks in unidirectional CFRP, Composite Science and Technol., Vol. 29, pp.273-292 (1987).

DOI: 10.1016/0266-3538(87)90076-5

Google Scholar

[2] Y. Miyano, M. Nakada, M. K. Mcmurray, and R. Muki, Prediction of fatigue life for polymer composites under temperature condition, Materials System, Vol. 17, pp.63-71 (1998).

Google Scholar

[3] J. Petermann and K. Schulte, The effects of creep and fatigue stress ratio on the long-term behavior of angle-ply CFRP, Composite Struct., Vol. 57, pp.205-210 (2002).

DOI: 10.1016/s0263-8223(02)00084-3

Google Scholar

[4] H. Furue and K. Nirano, Effects of fiber reinforcement and orientation on fatigue strength characteristics of short fiber-reinforced thermoplastics", J. Mater. Sci., Japan, Vol. 41, pp.232-238 (1992).

DOI: 10.2472/jsms.41.232

Google Scholar

[5] H. Furue, K. Nonakaand Y. Hashimura, Effects of short fiber reinforcement and mean stress on tensile fatigue strength characteristics of polyetherketon, J. Mater. Sci., Japan, Vol. 46, pp.1197-1203 (1997).

DOI: 10.2472/jsms.46.1197

Google Scholar

[6] H. Suzuki, J. Nakazawa, A. Teranishi and T. Haraguchi, A baisc study on the fatigue reliability of advanced reinforced nylon 46, Trans. JSME, Aeries A, Vol. 61, pp.1185-1189 (1995).

Google Scholar

[7] J. A. Bannantine, J. J. Comer, J. L. Handrock, Fundamentals of Metal Fatigue Analysis. p.66 (1990).

Google Scholar

[8] General rules for testing fatigue of rigid plastics, JIS-K7118 (1972), Japanese Industrial Standard Committee.

Google Scholar