基于小波变换的桥梁动态称重系统车轴高精度识别研究

Experimental Study of Structural Adhesives on Shear Performances at Different Temperatures

设计并进行了2组采用不同条件固化的胶黏剂的拉伸剪切试验，研究了结构胶黏剂的剪切强度和剪切刚度随温度升高的变化规律，以及不同温度下胶黏剂剪切破坏模式．试验发现，室温固化的胶黏剂再次经历高温后，其玻璃化温度Tg有了30℃左右的提高；随着温度的升高，胶黏剂剪切强度和剪切刚度总体上呈下降趋势，且在其玻璃化温度Tg前后20℃的区域内变化最为明显．研究表明，胶黏剂玻璃化温度是影响胶黏剂温度作用下剪切性能的关键因素，同时高温固化方式可以提高胶黏剂玻璃化温度，延缓胶黏剂剪切强度和剪切刚度的下降．在此基础上，引入玻璃化温度这一重要参数，给出了结构胶黏剂的剪切强度及剪切刚度与温度之间的关系模型，为实际工程应用提供了参考．

The structural performances including shear-strength, stiffness, and failure mode of structural adhesives with two different curing schedules at room and high temperatures were investigated. The test results showed that the high temperature curing on the structural adhesive after room temperature cu- ring can improve the value of glass transition temperature Tg by about 30 ℃. Moreover, the shear per- formances of the structural adhesives were deteriorated with the increase of the temperature, and the maxi- mum degradation rate occurred within the temperature range of Tg ± 20 ℃. It is indicated that the glass transition temperature Tg was critical to the shear behavior of the structural adhesive at the high tempera- ture. In a whole, the high temperature curing can improve the value of glass transition temperature, and it is helpful to delay the degradation of shear performance at the elevated temperature. Based on the test re- sults, the normalized relationship between＇the shear performances and temperature were eventually pro- posed, in which glass transition temperature was considered.