What rollercoasters can teach us about fatigue life of bridge connections
What rollercoasters can teach us about fatigue life of bridge connections
复制标题
过山车可以让我们了解桥梁连接的疲劳寿命
DOI：
10.1007/978-3-030-47634-2_2
复制
发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Sanayei, Masoud
中科院分区：
文献类型：
--
作者：
Tchemodanova, Sofia Puerto;Sanayei, Masoud
过山车是具有挑战性的结构。虽然不断变化的几何形状可以保证惊险的旅程，但由于复杂的几何形状而导致的负载模式的复杂性使得这些结构的测试和分析具有挑战性。疲劳损伤是土木工程结构在循环荷载作用下最常见的损伤类型之一，如桥梁和过山车。当结构反复经受一定次数的加载和卸载时，最终会发生疲劳裂纹。在应力超过一定限度的情况下，这种循环载荷会引起微裂纹，最终会扩展到构件或连接件的失效。由于过山车和桥梁连接之间的几何和结构相似性，类似的技术可以用于结构健康监测和剩余疲劳寿命的估计。单轴疲劳分析方法被广泛应用于桥梁连接的分析。然而，对于复杂连接的分析几乎没有指导。它们可以承受变幅、多轴和非比例载荷。在这种情况下，单轴疲劳方法是不够的，并可能导致低估。本文提出了一个利用应变记录收集的应变数据来理解和分析多轴疲劳损伤的框架。对非比例加载下的单轴和多轴疲劳分析方法进行了比较。所提出的方法适用于过山车和桥梁连接。采用临界平面法估算多轴疲劳寿命。结果表明，非比例加载和临界平面估计的准确性会导致剩余疲劳寿命的估计显着下降。该方法有望用于桥梁网络的实时疲劳预测和评估工具。
Rollercoasters are challenging structures. Although the ever-changing geometry can guarantee a thrilling ride, the complexity of loading patterns due to the intricate geometry make testing and analysis of these structures challenging. Fatigue-induced damage is one of the most common types of damage experienced by civil engineering structures subjected to cyclic loading such as bridges and rollercoasters. Fatigue cracking eventually occurs when structures undergo a certain number of loading and unloading recurrences. This cyclic loading under stresses above a certain limit induces microcracking that can eventually propagate into failure of a member or connection. Because of the geometric and structural similarities between rollercoasters and bridge connections, similar techniques can be used for structural health monitoring and estimation of remaining fatigue life. Uniaxial fatigue analysis methods are widely used for the analysis of bridge connections. However, there is little guidance for the analysis of complex connections. They can experience variable amplitude, multiaxial, and non-proportional loading. In such cases uniaxial fatigue methods are insufficient and can lead to underestimates. A framework for the understanding and analysis of multiaxial fatigue damage using strain data collected from strain rosettes is presented. Uniaxial and multiaxial fatigue analysis methods proposed for non-proportional loading are compared. Methods proposed are applicable to both rollercoaster and bridge connections. The critical plane method is used for the estimation of multiaxial fatigue life. Results show that non-proportional loading and the accuracy of the critical plane estimation can cause a significant decrease in the estimates of remaining fatigue life. This methodology is anticipated to be used for real-time fatigue prognosis and evaluation tools for bridge networks.