scholarly journals Effect of Temperature on the Tear Fracture and Fatigue Life of Carbon-Black-Filled Rubber

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 768 ◽  
Author(s):  
Wenbo Luo ◽  
Ming Li ◽  
Youjian Huang ◽  
Boyuan Yin ◽  
Xiaoling Hu

The mechanical behaviour of carbon-black (CB)-filled rubber is temperature-dependent. It is assumed that temperature affects the fatigue life of rubber products by changing the tear energy of the material. The static tearing behaviour and fatigue crack propagation behavior of CB-filled rubber at different temperatures were investigated in this study. The critical tear energy of the material was measured through static tear fracture tests at different temperatures; it is shown that the critical tear energy decreases exponentially with increasing temperature. A fatigue crack growth test of a constrained precracked planar tension specimen was conducted at room temperature; the measurements verify that the fatigue crack growth follows a Paris–Erdogan power law. Considering the temperature dependence of the critical tear energy, the temperature dependent fatigue crack growth kinetics of CB-filled rubber was established, and the fatigue life of the material at high temperatures was predicted based on the kinetics. The predictions are in good agreement with experimental measurements.


2003 ◽  
Vol 125 (1) ◽  
pp. 71-77 ◽  
Author(s):  
Muhammad Irfan-ul-Haq ◽  
Nesar Merah

This study addresses the effect of temperature on fatigue crack growth (FCG) behavior of CPVC. FCG tests were conducted on CPVC SEN tensile specimens in the temperature range −10 to 70°C. These specimens were prepared from 4-in. injection-molded pipe fittings. Crack growth behavior was studied using LEFM concepts. The stress intensity factor was modified to include the crack closure and plastic zone effects. The effective stress intensity factor range ΔKeff gave satisfactory correlation of crack growth rate (da/dN) at all temperatures of interest. The crack growth resistance was found to decrease with temperature increase. The effect of temperature on da/dN was investigated by considering the variation of mechanical properties with temperature. Master curves were developed by normalizing ΔKeff by fracture strain and yield stress. All the da/dN-ΔK curves at different temperatures were collapsed on a single curve. Crazing was found to be the dominant fatigue mechanism, especially at high temperature, while shear yielding was the dominant mechanism at low temperatures.



2012 ◽  
Vol 31 (3) ◽  
pp. 108
Author(s):  
Andrzej SKORUPA ◽  
Małgorzata SKORUPA ◽  
Tomasz MACHNIEWICZ ◽  
Andrzej KORBEL


Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1267
Author(s):  
Chunguo Zhang ◽  
Weizhen Song ◽  
Qitao Wang ◽  
Wen Liu

From tensile overload to shot peening, there have been many attempts to extend the fatigue properties of metals. A key challenge with the cold work processes is that it is hard to avoid generation of harmful effects (e.g., the increase of surface roughness caused by shot peening). Pre-stress has a positive effect on improving the fatigue property of metals, and it is expected to strength Al-alloy without introducing adverse factors. Four pre-stresses ranged from 120 to 183 MPa were incorporated in four cracked extended-compact tension specimens by application of different load based on the measured stress–strain curve. Fatigue crack growth behavior and fractured characteristic of the pre-stressed specimens were investigated systematically and were compared with those of an as-received specimen. The results show that the pre-stress ranged from 120 to 183 MPa significantly improved the fatigue resistance of Al-alloy by comparison with that of the as-received specimen. With increasing pre-stress, the fatigue life first increases, then decrease, and the specimen with pre-stress of 158 MPa has the longest fatigue life. For the manner of pre-stress, no adverse factor was observed for increasing fatigue property, and the induced pre-stress reduced gradually till to disappear during subsequent fatigue cycling.



2022 ◽  
Vol 154 ◽  
pp. 106554
Author(s):  
Shouwen Shi ◽  
Jiayao Li ◽  
Haiyan Li ◽  
Yihao Yao ◽  
Hailong Dai ◽  
...  


Author(s):  
Masayuki Kamaya ◽  
Takao Nakamura

Incorporation of the flaw tolerance concept in plant design and maintenance is discussed in order to consider the reduction in fatigue life due to the high-temperature water environment of class 1 components of NPPs. The flaw tolerance concept has been included in Section XI of the ASME BPVC. The structural factor (safety factor) for the flaw evaluation is considered in the stress, whereas it was considered in the design fatigue curve in Section III of the ASME BPVC. In order to apply the flaw tolerance concept to plant design and maintenance, it is necessary to assume the crack initiation and growth behavior. In this study, first, crack initiation and growth behavior during fatigue tests was reviewed and a relationship between the crack growth and fatigue life was quantified. Then, the safety factor was considered in the crack growth curve. It was shown that the crack size could be correlated to the usage factor and the flaw tolerance concept was reasonably considered in the plant maintenance by using the proposed virtual fatigue crack growth curve.



2018 ◽  
Vol 165 ◽  
pp. 09002
Author(s):  
Désiré Tchoffo Ngoula ◽  
Michael Vormwald

The purpose of the present contribution is to predict the fatigue life of welded joints by using the effective cyclic J-integral as crack driving force. The plasticity induced crack closure effects and the effects of welding residual stresses are taken into consideration. Here, the fatigue life is regarded as period of short fatigue crack growth. The node release technique is used to perform finite element based crack growth analyses. For fatigue lives calculations, the effective cyclic J-integral is employed in a relation similar to the Paris (crack growth) equation. For this purpose, a specific code was written for the determination of the effective cyclic J-integral for various lifetime relevant crack lengths. The effects of welding residual stresses on the crack driving force and the calculated fatigue lives are investigated. Results reveal that the influence of residual stresses can be neglected only for large load amplitudes. Finally, the predicted fatigue lives are compared with experimental data: a good accordance between both results is achieved.



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