5 Disasters Caused by Material Fatigue and What We Learned From 的m

凡尔赛火车相撞(1842年

5月8日下午, 1842, birthday celebrations for King Louis Philippe I had just concluded in Versailles. 数百名观众挤进数不清的火车车厢, 数量如此之多，以至于需要两个火车头来拉动. 当时火车正在返回巴黎的路上, 领头的机车断了一个车轴, 导致引擎脱轨. 的 chain reactions saw many of the trains' cars pile onto each other and catch fire, 这是由发动机燃烧室的分散造成的. Most estimates attribute 55 deaths to the accident and subsequent fire. 的 common practice of locking passenger doors at that time may have also been a contributing factor. 

的 Versailles train crash was the first of its kind in France and made world headlines. 的 crash also occurred during a period of time when metal fatigue and general degradation over time were not well understood, 这导致了普通民众的恐惧和困惑. 铁路公司, 政府机构, and scholars all set out to scrutinize and learn from the incident in order to prevent future catastrophes, as well as to restore public trust in the young railroad system as a safe and reliable means of transportation. 

William Rankine and August Wöhler were just a few of the many researchers who dedicated years to the advancement of the design, 测试, 以及火车车轴的维护. 正因为如此, the Versailles accident is considered by historians to mark the beginning of serious human interest and research into the area of fatigue and 断裂力学, which has allowed for the design and manufacture of safer, more durable goods and components. 

波士顿糖蜜灾难(1919年

1919年1月15日，2.300万加仑的油箱装满了 在波士顿的北端坍塌了 社区. 目击者称听到了什么 听起来像枪声，铆钉从 50英尺箱. 崩塌产生了糖蜜 海浪高达25英尺，时速高达35英里 在其鼎盛时期. 强烈的波浪损坏了钢 高架铁轨上的大梁被扫过 多座建筑物的地基坍塌 淹没了无数的城市街区. 

A full investigation ensued, which brought many contributing factors to the surface. 之一 the most critical factors was the neglect and general state of disrepair that the tank was in 当坍塌发生时. 报告指出，基本的泄漏和压力试验是 在将储罐投入使用之前被忽略的操作. 报告还指出 tank, when filled, leaked so badly that it had to be painted brown to hide the imperfections. 

尽管如此，坦克仍然在服役. Observations of the post-collapse evidence showed that the root cause originated near a manhole cover at the base of the cylindrical tank, where hoop stress 浓度 are 最高. It is believed that a fatigue crack was initiated near the manhole cover and grew to a 失效前的临界长度. 其他影响因素包括发酵 tank and a sharp rise in temperatures, both of which would have caused the internal 油箱的压力要大大提高.

德哈维兰彗星飞机坠毁，1954年

的 De Havilland Comet was the world’s first production commercial jetliner, produced by 英国的德·哈维兰. 彗星号是英国在二战中的最高成就 time, and further advanced their aviation superiority worldwide up until the first of several 致命事故最终归因于金属疲劳. 

In January 1954, BOAC Flight 781 experienced explosive decompression over the 从罗马到伦敦途中的地中海. 机上35名乘客和机组人员全部遇难 所有彗星飞机立即停飞. 经过广泛的搜索和恢复 任务结束后，官员们开始检查找到的飞机. 很明显，飞机 broke up in mid-air, and officials initially believed that an engine turbine explosion had 造成了事故. 所有的彗星和飞机都进行了涡轮改装 再次被允许飞行. 

Just weeks after being cleared for flight, another Comet aircraft, South African Airways Flight 201, experienced explosive decompression over the Mediterranean en route from 罗马到约翰内斯堡. 21名乘客和机组人员全部遇难. 这一事件 caused investigators to question their hypothesis of a turbine explosion as the main culprit 解压缩. 

After an extensive, multi-year investigation into both flights, it was determined that metal fatigue caused by design defects ultimately led to explosive decompression in both 实例. 的 metal fatigue originated near a forward window used for navigation. 几个 观察了影响因素. 首先，方形窗户的设计引起了 窗户角落的应力高度集中. 事实上，计算表明 that up to 70% of the aircraft's ultimate stress under pressure was concentrated on the 飞机窗户的角落. 其次，窗户周围的支撑 riveted instead of glued, as originally specified, and that the rivet holes caused fatigue 反复加压循环后产生裂纹. 

的 findings from these accidents were used to overhaul aviation requirements for 客舱强度. 此外，在飞机上消除了尖锐的点和边缘 设计，以减少应力集中.

亚历山大·L. Kielland石油平台，1980年

1980年3月27日，亚历山大. Kielland是一个石油钻井平台，驻扎在挪威 北海的水域. 200多名工人下班了 当一声“尖锐的裂缝”报告时，这艘船. 钻机突然倾斜成30度角. Five of the rig’s six anchor cables had snapped, leaving the final cable to support the 巨大的压力水平. 的 rig remained relatively stable in this position for a short period of time until the final cable fractured and the rig capsized into the sea completely. 超过 120 workers were killed during the capsizing, which stands as the worst disaster in 二战后的挪威水域. 

随后的调查是 能把事件拼凑起来 那天晚上，他们决定 坍塌的起因是由 疲劳开裂在其中之一 钻机的结构支撑. 的 然后将裂缝追踪到一个小的6毫米 连接无负载的角焊缝 支座法兰板与支撑. 角焊缝有一个差的轮廓和 明显的冷裂 导致…显著减少 疲劳强度. 法兰板为 也被明显的薄层削弱 撕裂，这增加了压力 浓度. 周期性应力 经历过的钻井平台 海洋进一步加剧了危机 情况.

逃避火车灾难，1998年

6月3日, 1998, a high-speed train traveling from Munich to Hamburg was derailed when a single train wheel failed, causing a chain reaction that lead to a bridge collapse and over a dozen derailed train cars. 

1号车上的钢轮胎在失效时引发了连锁反应, 从火车上被释放了吗, 然后陷进了第一辆车的地板里. 当火车经过一个转道口时, 嵌入的轮胎砰地一声撞在开关的导轨上, 导致导轨也嵌入火车, 是什么抬起了火车的车轴 偏离轨道. 当火车驶近第二个转弯处时, 脱轨的一个轮子撞到了开关, 这改变了它的设置. This caused the rear axle of car #3 to be pulled onto a parallel track, 使汽车剧烈脱轨, 它击中并摧毁了一座立交桥的主要支柱. 还有几辆车, 时速120英里, 击打桥梁直到它完全倒塌, 挡住了整个轨道. 的 remaining cars hit full speed into the rubble, causing a large pileup. 

总共有101人死亡，近100人受伤. 除其他因素外, investigators determined that the design of the wheel was flawed and lacked sufficient validation 测试 prior to implementation. Engineers had placed a rubber damping ring between the tire and wheel body in an effort to reduce vibrations during cruising. 这在几个方面增加了疲劳敏感性: 

• 的 tires were flattened into an ellipse as the wheel turned through each revolution (approximately 500,000 times during a typical day in 服务)，具有相应的疲劳效应.
•  与纯粹的单块车轮设计相比，裂纹也可能 形成在轮胎内部. 
• 当轮胎因磨损而变薄时，动力就会减小 夸张，导致裂纹扩大. 
• Flat spots and ridges or swells in the tire dramatically increased the 动态作用力对装配和大大加速磨损.

Other contributing factors included improper maintenance (records indicated that this particular wheel has failed to pass inspections on several occasions leading up to the crash, 尽管它从未被替换过), 跨桥设计(没有跨距设计), and the use of welds in the carriage bodies (led to “unzipping” during the crash) As a result of the disaster, all wheels with a similar design were replaced with monoblock wheels.

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