2004年4月6日
摇晃房屋的火车不会鼓励公众支持从道路转移到铁路的货运。Casco通过使用小型低能阻尼装置使火车更安静地促进火车的社会接受。
这environmental, social and economic costs of freight transport by road are key reasons to encourage the switch from lorries to the railways. Trains are cleaner, often quicker, use less energy and are safer for pedestrians – but railway companies that want to build new tracks or bring old lines back into use meet strong resistance. Concerns about infrastructure noise and vibration exposure raise strong objections from citizens and their representatives.
噪音和振动可能来自几种来源：车轮和轨道之间的粗糙接触是一种，但其他噪声接触不太明显，例如可以穿过地面的车轮，轨道和桥梁结构之间的相互作用，并在相邻建筑物中诱导振动。这CASCOProject使用创新的半活动控制设备为铁路上的噪音和振动提供了新的方法，该设备可以更有效地利用材料并最大程度地减少资源消耗。欧洲杯足球竞彩
“To reduce noise and vibration in steel structures you need to dissipate energy by damping – this is traditionally done by passive control,” explains project coordinator Dr Helmut Wenzel, managing director ofVienna Consulting Engineers（vce）。“被动控制使用结构的系统响应来实现阻尼。主动控制是另一种当前技术，这些技术依赖于大型电动执行器，但是对于大型结构，它们会消耗大量能量，需要定期维护。
“基于磁性流体阻尼器，CASCO开发的半活性设备CASCO开发是具有低功率需求的独立小型设备。这些含有在磁场中急剧改变粘度的流体，并且可以设置为从其支持的结构中消除振动。此类执行器安装在整个结构和铁轨下方的关键位置，以消除振动。它们通过局部耗散能量来防止振动动能进入土壤。一个关键优势是，由于它们的大小和稳健性，在许多情况下它们可以复古。”
桥接理论和实验
铁路隧道和桥梁是空气传播和通过土壤振动的强大噪音来源。CASCO财团选择了奥地利的Rohrbach铁路桥进行试验；这座钢桥建于1903年，不再使用。
最初使用连接到卧铺和桥上梁的传感器进行了广泛的测量。在有或没有火车通过的情况下测量发出的噪声 - 仔细消除了火车本身的噪声以隔离结构噪声。通过将观察到的振动频率与桥的结构元素匹配，可以隔离噪声的主要贡献。
这bridge was then dismantled, transported and reassembled at the欧洲结构评估实验室(ELSA) at the European Commission’s Joint Research Centre DG in Ispra, Italy. ELSA is a partner in the project with state-of-the-art equipment for active structural testing. “Once we rebuilt the bridge at Ispra, we repeated our measurements to ensure the system response of the structure was the same in the new location,” says Dr Wenzel. “This was important for calibration and to allow a true comparison.”
Another partner, the University of Applied Sciences in Vienna, developed a unique approach to modelling rheological fluids that was used in the design of the CASCO prototypes. It also has potential for more widespread application.
这outcome of the project is a suite of innovative semi-active devices shown to have excellent results in damping vibrational energy. In particular a new ‘cup-spring’ isolator was developed, the subject of a patent and capable of using both hydraulic and magneto-rheological mechanisms. Partners continue to develop the cup-spring isolator and are moving to commercial development for selected prototypes. Further, full-scale devices are being made for in-situ testing by奥地利铁路(ÖBB), which has dedicated an operational steel bridge for this purpose.
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