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The vulcanizate structure of filled compounds is affected by filler–rubber interactions (FRI) and the chemical crosslink density (CCD) of the matrix rubber. In particular, in filled compounds using a silica–silane system, FRIs due to silica–rubber coupling are a major influencing factor for the vulcanizate structure and physical properties. In this study, the effect of sulfur variation on the vulcanizate structure of silica-filled solution styrene–butadiene rubber compounds using a sulfide–silane coupling agent was studied. The vulcanizate structure according to sulfur variation was quantitatively analyzed using the swelling test and Flory–Rehner and Kraus equations. As the sulfur content increased, both FRI and the CCD increased, and it was confirmed that sulfur variation influenced the silica–rubber coupling efficiency through increased FRI. In addition, field emission scanning electron microscope images showed that increased FRI contributed to improvements in silica dispersion, abrasion resistance, and energy loss characteristics.

In the tire industry, indoor accelerated life tests as regulations have been performed to ensure tire durability performances instead of outdoor field test. The finite element method has been widely used to minimize real test time and cost, but prediction method for accelerated life test had hardly been made in the past. This study presents a rational methodology to predict the tire’s failure life at the steel belt edge region due to high speed regulation test. Based on the finite element analysis and fatigue characteristic of rubber material, a method to determine exact failure time is proposed. The steady-state rolling analysis by FEM to get strain energy density range(ΔSED) at the steel belt edge region and fatigue test of rubber compound to obtain ΔSED- number of cycle (Nf) curve were used. The reliability of proposed prediction method was verified by real indoor test.

Tire belt separation failure is occurred by internal cracks generated in #1 and #2 belt layers and by its growth. And belt failure seriously affects tire endurance. Therefore, to improve the tire endurance, it is necessary to analyze tire crack growth behavior and predict fatigue life. Generally, the prediction of tire endurance is performed by the experimental method using tire test machine. But it takes much cost and time to perform experiment. In this paper, to predict tire fatigue life, we applied deterministic fracture mechanics approach, based on finite element analysis. Also, probabilistic analysis method based on statistics using Monte Carlo simulation is presented. Above mentioned two methods include a global-local finite element analysis to provide the detail necessary to model explicitly an internal crack and calculate the J-integral for tire life prediction.