Effects of site operating conditions on real site TKPH (tonne-kilometer-per-hour) of ultra-large off-the-road tires

Abstract

The objective of this study is to investigate the effects of site operating conditions on the real site TKPH (tonne-kilometer-per-hour) of ultra-large off-the-road (OTR) tires. To achieve this, a novel finite element OTR tire thermal (OTRTire-T) model was developed to predict the temperatures of OTR tires. As per the results from the OTRTire-T model, the cycle length coefficient K1and the site ambient temperature coefficient K2were refined and then compared with existing coefficients in the literature for cross-verification. After cross-verification, these K1and K2coefficients were used to calculate the real site TKPHs. The real site TKPHs were investigated under different site operating conditions (i.e. average vertical tire loads, average cycle speeds, ambient temperatures, and cycle lengths). The results showed that the real site TKPH increased with a rise in average cycle speeds from 10 to 45 km/h and an elevation of ambient temperatures from −30°C to 40°C. At low ambient temperatures below 15°C, as per the real site TKPH, the loading capacity of the truck may increase (compared with its rating payload of 363 t) at mine sites. In addition, the real site TKPH increased relatively rapidly when the cycle lengths were short but rose slowly, or even leveled off, with a further increase in cycle lengths.