Issue #100 Technicaltidbits Materion Performance Alloys

APRIL 2017 ISSUE #100 TECHNICALTIDBITS MATERION PERFORMANCE ALLOYS

LEARNING FROM FAILURES AND ENGINEERING DISASTERS As an engineer, you can learn more from a single failure than Disasters frequently from 1000 successes. happen outside of This is especially true if the failure is your own design, • Dam collapses (South Fork Dam, Sayano- 1970’s Hollywood as the lessons are personal and deeply ingrained. Shushenskaya Dam, St. Francis Dam) movies. – Using However, you do not have to learn from your own • Failure of Levees around New Orleans during short-term testing to failures, as engineers, architects and designers have Hurricane Katrina been making design mistakes (and occasionally estimate long-term failure • Therac-25 overdoses goofing up royally) for millennia. The point here is not to learn to assign blame. It is After any engineering disaster, there is always an important to study not just how something failed, but inquiry to determine who or what was responsible. why it failed. Here are some key considerations to Failure Those approaching an inquiry from a legal point of look for when examining historical failures: Engineering view are most interested in finding out if anyone should be paying compensation and whether or • What decisions led to the failure? Disaster not criminal charges should be filed. Engineers can aid • Was a previously unknown natural phenomenon this effort as expert witnesses, but the most import- to blame (like aeroelastic flutter in the Tacoma ant role of the engineer is to find out exactly what Narrows Bridge collapse, or the trench effect in went wrong, so that the disaster is never repeated. the Kings Cross station fire)? • Were there flawed assumptions used in the design? Here is a partial list of some of historically important disasters to study: • Was something not communicated properly (such as the valid reasons for delaying the launch of the • Structural collapses (Kansas City Hyatt Regency Space Shuttle Challenger)? Walkway and Sampoong Department Store) • Were safeguards or warning indications ignored • Eschede derailment or ineffective (such as iceberg warnings the night • Ship Disasters (Vasa, RMS Titanic, Sultana, Halifax of the Titanic sinking?) explosion) • Were previously successful designs used at a scale • Space Exploration Disasters (Apollo 1, Space where they had never been tested (as in the highly Shuttles Challenger & Columbia) accelerated fatigue failure of the low vibration • Bridge Collapses (I-35W, Tacoma Narrows, Silver, wheels on the Eschede train derailment)? Tay, Quebec and Ashtabula bridges) • Were safety practices ignored in order to meet • Nuclear Disasters (Three Mile Island, Chernobyl, cost or time pressures (like in the Sampoong and Fukushima) shopping mall collapse)? • Surprisingly Deadly Fires (Cocoanut Grove, • Was a process or component changed without Iroquois Theater, Collinwood school, King’s Cross examining all the possible ramifications of the station, Summerland) change (such as the support mechanism for the The next issue of Technical Tidbits will discuss nonlinear • Airship Disasters (Hindenburg, USS Akron) Kanas City Hyatt Regency Walkway)? scaling effects. • Industrial Disasters (Deepwater Horizon • Were materials used beyond their safe limits (as in explosion, Bhopal Union Carbide leak, coal mine the Space Shuttle Challenger disaster) fire in Centralia, Pennsylvania) ©2017 Materion Brush Inc. MATERION PERFORMANCE ALLOYS LEARNING FROM FAILURES AND ENGINEERING DISASTERS (CONTINUED) • Were materials used in inappropriate ways or in 2) Clear, concise communication is essential, inappropriate locations? whether you are speaking, writing, or even Written by Mike Gedeon of Materion • Were incompatible materials used together? creating charts and graphics. You may have to Performance Alloys Marketing convince a non-engineer to make an engineering • Were untried materials with fatal flaws used (like Department. Mr. Gedeon’s primary decision. You had better be able to communicate focus is on electronic strip for the in the Cocoanut Grove and Summerland fires)? why it is necessary. Many organizations provide automotive, telecom, and computer • Was something overlooked when coding control continuing education on improving your commu- markets with emphasis on software (as in the Therac-25 controls)? nication skills. Some examples include Wylie application development. • Was it tested under conditions that there much Communications Inc., Graphics Press LLC, and References: less severe than real world conditions? most professional skills development organizations. Petroski, Henry • Did a series of otherwise survivable circumstances 3) Remember to take into account how properties, To Engineer is Human ©1992 combine or interact in an unexpected way? forces, pressures, etc. scale when making things Vintage Books larger, smaller, faster, hotter, more powerful, etc. • Was a miscalculation made and not caught Fawcett, Bill It Looked Good on in subsequent design reviews (like the Designs that are successful and robust at one scale Paper ©2009 Bill Fawcett and I35-W collapse)? may fail miserably in another scale. Associates 4) Finite Element Analysis and other related • Were unexpectedly extreme conditions Loutham, Mac. Life Lessons of a involved? (For example, was the dam that simulation packages have given engineers the Failure Analyst ©2016 ASM was designed to withstand the 100 year storm confidence to reduce the safety factors and International eliminate the overdesigns that used to be hit by the 500 year storm?) Tufte, Edward R. Envisioning commonplace in engineering. While overdesigned • Etc. Information ©1990 Edward Rolfe products with very high safety factors would be Tufte Graphics Press LLC. Keep in mind that it is often an interaction of multiple more tolerant of errors in calculations, the margin for error disappears when the safety factors Tufte, Edward R. causes that separates a true disaster from a simple The Visual Display of Quantiative failure. Combinations of multiple errors tend to make approach 1. In other words, it is very easy to get Information ©2001 Edward Rolfe disasters much worse. false confidence from a simulation, where a single Tufte Graphics Press LLC. false assumption could very easily lead to failure. There are also lessons to be learned from some Please contact your local sales more recent, high-profile failures. Being an engineer is like being in the medical or representative for further police professions, since the general public information on material hardness • Lithium ion battery fires in aircraft, smart phones, expects you to be infallible. A simple mistake or other questions pertaining to laptop computers and hoverboards. Materion or our products. can cost people their lives, or at least result in • Automotive recalls for unintended acceleration, significant damage to property. When working on airbag inflator ruptures, ignition switch shutoffs, etc. Health and Safety any new design that may be responsible for keeping Handling copper beryllium in solid The most important lessons to learn from failures people safe, you need to ask yourself if any of the form poses no special health risk. and disasters are as follows: common causes found in the historical disasters Like many industrial materials, applies. The best way to protect against failure is to beryllium-containing materials 1) Always put safety first. Look for ways that study the common causes and lessons learned, and may pose a health risk if your design can fail. Conduct adequate testing then to apply those lessons to your work. For added recommended safe handling and screening whenever possible to prevent practices are not followed. benefit, the references section contains a number of unexpected failures. Testing conditions should Inhalation of airborne beryllium key works on disasters and engineering failures. Every at least be equivalent to real world conditions. may cause a serious lung disorder engineer should read these multiple times. in susceptible individuals. The Occupational Safety and Health Administration (OSHA) has set mandatory limits on occupational respiratory exposures. Read and follow the guidance in the Material Safety Data Sheet (MSDS) before working with this material. For additional information on safe handling practices or technical data on TECHNICALTIDBITS copper beryllium, contact Materion Performance Alloys Sales Materion Performance Alloys 6070 Parkland Blvd. +1.216.383.6800 or your local representative. Mayfield Heights, OH 44124 800.321.2076 [email protected] Technical Service +1.216.692.3108 800.375.4205 [email protected]