真空管道结构模拟试验系统研制与试验验证

为研究真空管道运输系统管道结构在真空度和温度载荷作用下的结构力学问题,应用相似理论制作了应力相似比为1的真空管道模型,研制了真空管道结构模拟试验系统。系统由模型管道、真空系统、温度控制系统和数据采集系统4个子系统构成,具备真空度-温度耦合环境的模拟能力。在真空度0~95 kPa、温度30~60℃范围内,可以对真空管道结构力学性能开展试验研究。应用该系统完成了2组测试试验,结果表明,模型管道的结构应力与真空度和温度均呈线性递增关系;真空度和温度对管道结构的作用效果相互独立,对管道横截面不同位置的作用效果差异较大。试验系统实现了对真空管道运行环境的模拟和管道结构力学行为的监测,提供了真空管道力学行为的一种试验方法,为其在水土压力、列车运行载荷等更复杂条件下的力学性能研究奠定了基础。

Characterization of Structural Mechanics of Vacuum-Tube with Lab-Built Simulator:An Experimental Study

The experimental simulator was developed,mainly comprising a 3000 mm×1250 mm×1140 mm concrete tube,pumping-unit,generators of continuous/cyclic pressure and temperature loads,monitors/heaters/sensor/gauges and data acquisition/procession unit.The influence of the pressure and temperature loads,possibly produced by a fast running train in evacuated tube and varying in 1 atm~95 kPa and 30~60℃ ranges,respectively,on the structural mechanics properties of tube-wall was investigate with the simulator.The preliminary results show that the pressure and temperature loads all have a major impact.To be specific,an independent increase of temperature or an independent decrease of pressure linearly increased the stress of tube-wall; and the stress,originating from continuous and cyclic pressure loads and measured on the top/right/left sides,had U-shaped and V-shaped time-evolution curves,respectively.We suggest that the lab-built simulator be of much technological interest in development of vacuum tube transportation.