Fatigue resistance of natural rubber in seawater with comparison to air

Abstract

International audienceFatigue properties of filled natural rubber in seawater environment are investigated by uniaxial fatigue and crack propagation experiments, and the damage is analyzed by scanning electron microscopy. The behavior under relaxing and non-relaxing loading conditions is studied and the results are compared to those obtained in air environment. For relaxing loading conditions, fatigue behavior is the same in both environments. Under non-relaxing conditions at large strain levels, for which the influence of strain- induced crystallization is important, fatigue life is longer in seawater. Such behavior could be explained by increased internal temperatures of specimens tested in air due to lower heat conductivity of air as compared to seawater. Such conclusion is also supported by the damage mechanisms observed under non-relaxing loading conditions

The Effect of the Salt Water Aging on the Mechanical Properties of Epoxy Adhesives Compounds

“…A similar trend was observed in the present study despite the fact that salt water was compared to tap water. Narynbek Ulu et al [27] underlined that the damage mechanisms (in the case of elastomers) in seawater became complex and not completely understood. Further research on this subject is planned, because it is an interesting issue, especially in the field of using laminates and epoxy composites in the construction of yachts, as well as protective covers for vessels, which was also emphasized in Nash et al [33] work.…”

“…As already mentioned, epoxy adhesives and coatings used in the marine industry are often exposed to the impact of seawater, one of the most harmful environments affecting the service life of engineering structures. Diverse aspects of the seawater's environmental effect on the strength of adhesive joints and adhesives were analyzed by different authors [21][22][23][24][25][26][27]. Fernades et al [13] characterized the fracture envelope of a commercial epoxy adhesive used in the automotive industry as a function of the water content in the adhesive.…”

Effect of Wall Thickness on Stress–Strain Response and Buckling Behavior of Hollow-Cylinder Rubber Fenders

“…For convenience, the polynomial function E s (e c ) is called the energy polynomial function hereafter and is given by Equation 13. (14) According to Equation 14, the value of S c at any given value of e c in the range of 0-50% can be estimated directly if the energy polynomial function is available. In other words, a further fourth-degree polynomial function can be derived for S c in terms of variable e c .…”

“…For convenience, the resulting polynomial function, S c (e c ), is denoted as the stress polynomial function in the remainder of this study. Figure 8a-e compare the measured S c − e c curves for the five rubber fenders with different wall thicknesses with the simulated ones obtained by using the proposed stress polynomial function based on Equation (14) and the coefficient values are summarized in Table 3. A good fit was observed between the simulated curves and the measured ones in all cases.…”

“…The fenders used in commercial docks, ports, and harbors are mostly fabricated from rubber because of its outstanding performances, like low transmission force and excellent energy absorption capacity. In addition, rubber has many more favorable properties such as high flexibility, good resilience, a long service life [1][2][3][4][5][6], an excellent resistance toward temperature [6][7][8][9][10][11][12], saltwater [13,14], and other environmental factors [15][16][17][18][19].…”