The wear behavior of tire tread rubber composites has attracted widespread attention of researcher duo to its serious environmental pollution and high frequency of occurrence for a long time. Herein, a new test method is developed, an improved Akron friction testing machine on a laboratory scale was utilized to estimate the wear loss and mechanism of the rubber composites under rolling and sliding coupling condition. The results indicated that the wear loss quickly increases with the increase of the relative sliding velocity. The main wear mechanism, including adhesive, thermofatigue, tear and curl wear, was governed by the thermal deposition of the worn surface. Scanning electron microscope analysis showed thermal decomposition tear region gradually expanded on the worn surface by increasing relative sliding velocity. The heat distribution numerical analysis supported the experimental results, which confirmed that the heat distribution of the worn surface is entirely consistent with the distribution of the thermal decomposition tear region.

In this study, axial stiffness analysis of corrugated tubes was carried out numerically and experimentally. By performing axial loading-displacement analysis, a so-called stiffness weakness factor Kf for the corrugated tube was proposed and formulated. Both corrugated and smooth double-tube heat exchangers were designed and tested under thermal loadings. Results show that the proposed formula for the stiffness weakness factor Kf is accurate enough for the engineering application of the corrugated tubes in constructing heat exchangers.

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