Characterization and Quantitative Analysis of Crack Precursor Size for Rubber Composites

Abstract

In the field of engineering, the annual economic loss caused by material fatigue failure reaches 4% of the total economic output. The deep understanding of rubber fatigue failure can help develop and prepare rubber composites with high durability. The crack precursor sizes within the rubber composites are vital for the material mechanical and fatigue properties. In this study, we adopted three different characterization methods to analyze crack precursor sizes and their distribution. First, based on the theoretical formula of fracture mechanics, the size of the crack precursor was deduced from 180 μm to 500 μm by the uniaxial tensile experiment combined with tear test (nicked angle tear, planar tear and trouser tear). Second, by combining the uniaxial fatigue test of dumbbell specimen with the fatigue crack growth rate test, the average size of the crack precursor was calculated as 3.3 μm based on the Thomas fatigue crack growth model. Third, the average size of the crack precursor was 3.6 μm obtained by scanning electron microscope. Through theoretical calculations and experimental tests, the size and distribution of the crack precursors of rubber composites were systematically presented. This work can provide theoretical guidance for the improvement of fatigue performance of rubber composites.

Influence of Silica Specific Surface Area on the Viscoelastic and Fatigue Behaviors of Silica-Filled SBR Composites

“…For each compound, tear testing was performed using a nicked angle tear specimen [ 31 ]. The measurement was carried out with the Instron 5967 machine at a testing rate of 500 mm/min.…”

“…The crack precursor size of the samples can be calculated based on the equation [ 31 ]: where is the crack precursors size (µm) and and are the stress (MPa) and strain (%) at break obtained from the quasi-static testing, respectively.…”

“…The heterogeneities responsible for the detriment of properties were considered as crack precursors [ 28 , 30 ]. Hao Guo et al [ 31 ] investigated the crack precursors by means of tensile and tear tests, showing that a comparative study of crack precursors can be performed using scanning electron microscopy (SEM).…”

Enhanced Fatigue and Durability Properties of Natural Rubber Composites Reinforced with Carbon Nanotubes and Graphene Oxide

“…The sizes of the crack precursors were determined using the critical tearing energy method, as described in our previous report [ 35 ]. The crack growth rates of the composites were determined using a crack extension analyzer (DMA + 1000, METRA VIB, Lyon, France) at 20 Hz and 25 °C.…”

A New Multiparameter Model for Multiaxial Fatigue Life Prediction of Rubber Materials

“…In general, it is established that the fatigue failure of any component is divided into three stages: crack nucleation stage, crack propagation stage, and component failure. Although there are works in the literature that study the fatigue phenomenon of these materials during the crack propagation stage [23], this paper establishes its objective in the crack nucleation stage. This is because, in general, stress [51].…”