Finite element analysis of tire thermomechanical coupling rolling resistance
Based on the essential mechanism of tire rolling resistance, a finite element analysis method of handing thermomechanical coupling for rolling resistance was proposed. In order to verify the method, rolling resistance and temperature measurement experiments of rubber wheels made of tread rubber were conducted on a measured on RRS-?? model rolling resistance testing machine. Finite element analysis of rolling resistance and temperature of the wheels were also done, the results shew consistently coincides with that of test. Then the finite element analysis method was used to predict 12.00R20 tire rolling resistance and the influence factors on rolling resistance, such as inflation pressure, vertical loads and speeds were also analyzed.
Truck Tire Thermal-Mechanical FEA and DMA with Application to Endurance Evaluation4
Abstract This work presents a thermal-mechanical finite element analysis (FEA) of a typical heavy-duty radial truck tire on both drum and roadway. The calculated footprint pressures, strain energy density, and steady-state temperature distribution are compared between two cases. In addition to structural and thermal simulation techniques for obtaining stress, strain, and temperature distributions in the tire key areas, several material analysis techniques are also used to characterize the tire rubber materials. Temperature, frequency, and strain scan tests are conducted to obtain the dynamic mechanical properties of the tire rubbers of interest. Furthermore, the changes of the materials’ dynamic mechanical properties with fatigue have been investigated by testing tire materials before and after drum endurance tests. It has been found that different parts show different changing trends in dynamical properties after endurance tests, which might indicate different failure mechanisms. Combining the materials’...
Traceability strategy for gear-pitch-measuring instruments: development and calibration of a multiball artifact
There is a strong demand to ensure the traceability of gear-measuring instruments (GMIs). We propose a multiball artifact (MBA) for the evaluation of pitch-measuring accuracy. The aim of the MBA is to transfer the minimum uncertainty from a calibrated value at the National Metrology Institute of Japan (NMIJ) to a measured value of GMIs at a shop floor. The MBA is composed of equally spaced high-accuracy balls around an axis. The pitch-measuring accuracy of GMIs is evaluated by measuring the angular pitch deviation of the balls instead of the angular pitch deviation of a gear. We calibrated the angular pitch deviation using a coordinate measuring instrument (CMM) at the NMIJ and adapting a multiple-orientation technique. We proposed a calibration strategy of the angular pitch deviation. The calibration value of the pitch deviation for the MBA at the NMIJ was obtained with a measurement uncertainty (U95) of 0.2 µm. We evaluated the pitch-measuring accuracy of a GMI using the calibrated MBA. Each value of U95 for the cumulative and single pitch deviations for the left and right flanks was less than or equal to 0.5 µm. The small uncertainty was transferred from the NMIJ to the GMI.