Reliability of Maintained Systems Subjected to Wear Failure Mechanisms: Theory and Applications

By Franck Bayle

Today, the reliability of systems has become a major issue in most industrial applications. The theoretical approach to estimating reliability was largely developed in the 1960s for maintenance-free systems, and more recently, in the late 1990s, it was developed for maintenance-based systems.

Customers’ expectations concerning reliability (as well as maintenance, safety, etc.) are growing ever more demanding over the generations of systems. However, the theoretical methods used to handle the systems are not suitable when aging mechanisms are present.

This book proposes a theoretical approach to estimate all of these quantities correctly. In addition to the theoretical aspect, it details a number of issues that any industrial system will meet sooner or later, whether due to design flaws, the batch of components, manufacturing problems or new technologies that result in the aging of mechanisms during their operational use.

• Language: English
• Publisher: Wiley
• Release date: Apr 10, 2019
• ISBN: 9781119610656

Book preview

Foreword by Christian Moreau

DGA of my professional career, I have often found that reliability is the weak link in the development of modern electronics, from component to system. While manufacturers naturally look for the best compromise between performance and cost, reliability is often a late integrated constraint for teams other than those responsible for designing our systems. Certainly, in terms of semiconductors, the concepts of DFR (Design for Reliability) were born in the 2000s but it always seemed to me that these concepts had been introduced primarily for commercial reasons rather than for a real willingness to serve the customer harmoniously and durably. A manufacturer’s worst fear is dealing with a high early failure rate during the warranty period of a product as this can sometimes lead to very serious consequences in case of recalls.

In another area, we have even arrived at the notion of planned obsolescence, in total contradiction with the objectives displayed in the different summits in terms of sustainable development [COP 21]. Numerous times, I have encountered the paradox of mirroring the MTBF (mean time between failure) of the previous system without thinking about what Moore’s law could do in terms of the positive consequences for the reliability of a system. I have not encountered any serious confusion between lifetime and MTBF, sometimes even publicly confessed on the websites of semiconductor manufacturers because it is practical while being erroneous. I even coined the term marketing reliability to describe this phenomenon.

The author of this book does not compromise with the scientific truth in the field of reliability, as it is the strength of this book. We live in a world where everything is accelerating, hence we have less and less time to take a step back from what we do every day. Reading this book makes it possible to combat this paradigm of the beginning of the 21st Century. Educating in order to better combat ignorance, is this not the perfect illustration of the saying science in the service of man?

In 1965, Gordon Moore revolutionized the evolution of microelectronics by laying the foundations for the eponymous law. After 55 years, I modestly wish to put reliability at the heart of future developments. I am sure that this book will help.

Christian MOREAU

Senior expert

DGA

Foreword by Claude Sarno

Being a Director of Product Development, I am not an expert in reliability, but during my almost 40 year career at Crouzet, Sextant Avionique and Thales, I have had to deal with reliability issues many times as a manager of the design office within which are integrated specialty engineering and mechanical, thermal, CEM simulations, etc.

Reliability, at least in its predictive part, often appears to computational engineers, as being empirical in contrast with powerful tools such as finite element calculations that make it possible to perform fatigue failure analyses which are becoming increasingly accurate physics of failure (PoF).

In fact, experience shows that these methods are not to be used alone but should be used together to better take into account the risk of failures.

Franck’s book establishes the theoretical basis of this discipline, through concrete examples to illustrate the use of mathematical formulations.

It also allows the non-expert to understand the basic concepts of reliability, in a pragmatic way while allowing experienced engineers to find in a single book specific developments and representative examples of applications that may be encountered among aeronautical equipment manufacturers.

The objective that I had set for Franck during the annual interviews was to transmit his know-how as an expert in the field of reliability before his retirement. Through this book, we can say that the mission is perfectly accomplished with a character of universality since it can also benefit the whole profession, the student, the specialized engineer, as well as the layman who wants to learn this discipline.

Another important point that I want to emphasize, having been fortunate enough to have Franck on my team, is his human and convivial nature.

He brought a lot to the atmosphere of the team and not one day passes without one of his puns creating a good mood, although it sometimes takes a few seconds to decode any finesse, a bit like his reasoning of reliability.

In conclusion, this is a structured book, written by a passionate character, which I invite everyone to browse.

Claude SARNO

Flight Avionics

Director of Product Development

Acknowledgments

This book could not have been published without the help of certain people. I would first like to thank the people who played a major role in my professional career and who gave me the means to acquire my expertise, Jean Riaillon, Laurent Portrait and Claude Sarno.

Then, I would especially like to thank Philippe Bogdanik and Christophe Taurand who, during my career as an electronics engineer, taught me to be more rigorous, to ask the right questions, to question myself to obtain knowledge, and to become a real expert in this particular area that is reliability.

In the field of reliability, I particularly thank Mr. Laurent Denis, Director of the company StatXpert and Mr. Christian Moreau of the DGA, who also often guided me towards a more in-depth expertise.

I also thank, for their scientific expertise, Mrs. Lambert Pierrat, Olivier Gaudoin, Léo Gerville-Réache and Vincent Couallier who allowed me to acquire an advanced level of expertise in this field.

Finally, I thank all my family for supporting and encouraging me throughout the writing of this book.

Introduction

In today’s world, the word reliability is evermore present in current conversations. Of course, in technical fields such as aeronautics, railways, space and so on, reliability is already widely used because it is a major parameter whether for performance, security, cost or brand image