Vibration-based damage detection for bridges

桥梁是加拿大经济所依赖的交通网络的重要组成部分。因此，必须将桥梁的状况或“健康”保持在可接受的水平，以确保公共安全和维持适当的服务水平。随着桥梁人口的老龄化和个别桥梁结构的恶化，对其状况进行准确评估变得越来越重要，以便能够就所需维修的时间和程度做出决定。从概念上讲，这可以通过各种形式的监测来实现。一般来说，损伤越早被发现和修复，长期维护的成本就越低。不幸的是，目前的监测方法往往不能提供足够的信息，以便在其发展的足够早的阶段就能检测到损害。目视检查是大多数桥梁监测策略的基础，已被发现非常不可靠。其他基于技术的方法通常实施起来既昂贵又耗时，并且不一定能够识别桥梁无法到达的部分的损坏。这项建议侧重于另一种监测方法，这种方法依赖于测量桥梁振动方式的变化，以此作为存在损坏的指标；这种方法不受同样的限制。

Bridges form a critical component of the transportation network upon which the Canadian economy depends. It is therefore imperative that the condition or "health" of bridges be maintained at an acceptable level to ensure public safety and sustain adequate levels of service. As the bridge population ages and individual bridge structures deteriorate, it becomes increasingly important to have an accurate assessment of their condition so that decisions can be made regarding the timing and extent of needed repairs. Conceptually, this can be achieved through various forms of monitoring. In general, the earlier damage can be detected and repaired, the less it will cost to maintain in the long-term. Unfortunately, current monitoring methods are often not able to provide sufficient information to allow the detection of damage at an early enough stage in its development. Visual inspections, which form the basis for most bridge monitoring strategies, have been found to be remarkably unreliable. Other technology based methods are often costly and time consuming to implement and are not necessarily capable of identifying damage to the inaccessible parts of a bridge. This proposal focuses on an alternative approach to monitoring that relies on measuring changes to the way a bridge vibrates as an indicator of the presence of damage; this approach does not suffer from the same limitations.