John Draper is the founder and director of SIMULIA’s fe-safe, which became part of the Dassault Systèmes portfolio in 2013. He is a recognized authority on fatigue analysis and has been a regular presenter at software conferences around the world. Draper shared some of his accumulated wisdom with attendees at the 2016 Science in the Age of Experience conference in Boston. He retired this year after an incredible career.
SIMULIA Community News spoke with John recently:
SCN: How did you come to work in fatigue?
DRAPER: I’ve always been interested in aircraft and during an apprenticeship with an aircraft company I worked with the ‘fatigue design’ team. The topic seemed very interesting because you need to know so much about what was happening to the whole aircraft, not just the part you were working on. I created the role of trying to develop improved methods, and I wrote a simple fatigue life computer program in the early 1970s. The most valuable part of my education was a two-year post-graduate course in advanced engineering at the College of Aeronautics at Cranfield, because it combined theory with practical design projects.
SCN: You are a recognized authority in the fatigue industry. What qualities does an engineer need to develop in order to become an expert in their field?
DRAPER: I don’t think anyone is really an expert because the more you learn the more you realize there is more to learn. I’ve spent my career in the single field of metal fatigue, in both aircraft and rail, and for the past 30 years mainly focused on software development and training courses for many industries. This wide range of experience has been very helpful. And being prepared to question what is being done and being open to new methodology.
Hear John present on fatigue analysis. Watch the webinar: “Improve Product Design with Modern Fatigue Technique”
SCN: How many years had your company, Safe Technology, been attending SIMULIA SCCs before being acquired by Dassault Systèmes and how does your joining DS enrich the experience and power of simulation software?
DRAPER: I think we attended an Abaqus conference in 1998 when it was HKS, and we made presentations at the 1999 Abaqus conference. So this was 15 years before we were acquired by Dassault Systèmes. HKS made an early decision to sell fe-safe as a product. This was very important in helping us establish fe-safe, and it certainly enhanced our credibility. In recent years the market for simulation software has grown and it is embracing design engineers as well as technical specialists.
Users want to carry out an analysis without running a sequence of programs—they want the user interface to do that and make it seamless. And for many components, although the designer calculates stresses, temperatures, vibration modes and other things, the ultimate goal is to assess the fatigue strength. fe-safe adds this capability to the DS simulation portfolio.
SCN: You mentioned that the accuracy of fatigue life predictions has been transformed since the 50’s. How and why?
DRAPER: For over a century fatigue assessment was a simple calculation using engineering stresses, with empirical factors to try and get a reasonable life estimate. These factors were often very difficult to estimate and were often derived from experience of past designs. So you never knew when you would step outside their range of validity. Modern fatigue analysis really started to develop in the 1950s, although you can trace some key ideas back to the early 1900s. The focus has been to try and replace empirical correction factors with something more scientific. fe-safe doesn’t request any correction factors.
SCN: What are your plans for after retirement?
DRAPER: Many! I’ve always been an active hill-walker with a bit of mountaineering. I do some cycling. Twice I’ve helped sail a small boat round the north coast of Scotland and I plan to do another sailing trip in September this year. I have a little MG sports car and I’m slowly building a replica of a 1930s Jaguar two-seater. I enjoy concerts, art museums and the theatre. I have three children and three grandchildren. I have a backlog of CD’s to play and books to read…
SCN: Do you have any advice for young engineers about the future of the profession, or how to develop an individual career path?
DRAPER: I think engineering is one of the most exciting and satisfying professions. It’s changing so rapidly, in part because of computing power. There is so much innovation and so many opportunities to contribute to this innovation. I don’t like giving advice but a good start is to find an area of engineering that gives real interest, read as much about the subject as possible, be committed, be open to new ideas and keep questioning things.
