With so much scientific tools, why do designs fail?Why the unsinkable Titanic sank? Why did the thoroughly tested Columbia space shuttle burned out on return? Why Toyota had to call back thousands of cars designed by expert engineers?Design might fails because somebody made a stupid mistake in his calculations, like in the old joke about the bridge that fell down because the engineer forgot to multiply by two. It might happen, but it is extremely rare. Most design failures happen because one spe
An article appeared in an engineering forum entitled Why Designs Fail. As I thought about the article and the examples presented, the Titanic, Tacoma Bridge, etc., I realized mitigating the consequences of a failure are more important than preventing the failure.
One of the subjects I did not learn in the classroom was Failure Mode and Effect Analysis (FMEA). I do not intend to cover the subject of FMEA but would like to emphasize one small portion. FMEA was introduced to me on my first jo
A Journal of Applied Mechanics and Mathematics by DrD
Machinery Dynamics Research, (c) 2016
Professional Societies -- Or Not?
This post is written in response to questions raised by one of our regular participants, a young engineer in Australia. What I have to say here is based entirely on my own, very American, experience, and others may have different ideas. I would encourage a general discussion in the comments, so that we may see
A warning by Dr. D. posted on this site reminded me of two funny incidents. Dr. D. was responding to the use of PPM for perpetual motion machine. These initials according to Dr. D. are used for Permanent Magnet Motor. This may sound trivial, but the following, I was not warned about in school.
If you have ever worked in big corporations especially defense or government related there are new languages you will need to learn. Shortly after joining a defense company, I told my boss if I did
I have learned to take most news reports with a pound of salt. The VW diesel scandal may deserve at least a pinch of salt. That is my take from the attached article, “VW Dieselgate…”
Most who have taken exams to receive their medical, law, or engineering licenses would likely not pass the exam on any given day as normally administered. I am sure I could solve a sufficient number of problems to get a passing grade on a PE exam but not in the 8-hour window.
In the real world, our clients
A Journal of Applied Mechanics and Mathematics by DrD, # 22
(c) Machinery Dynamics Research, 2016
Torsional Stiffness of a Shaft -- Part I
A shaft is a common machine element, used to transmit rotational motion and torque from one component to the next. It is clear that the length of the shaft must be sufficient to span the distance from the first component to the second, but what should the diameter be? The answer to this quest
Challenges Before Engineers
The unintended outcomes of past engineering solutions to the problems have adversely affected environment. Environmental sustainability, health, reducing our vulnerability adding to the joy of living is essential for humanity to flourish. This forms challenges not only for engineers but also to others.The challenges relate to energy and the environment, health and medical sciences, education and information technology, infrastructure and security. Through creati
What will happen if we condense the exhaust gas of coal gasification after passing through the gas Generator and then feed it to water treatment plant and then drain that water to the ground or reuse it. Can this be possible? No exhaust gas or reduced exhaust gas issue to environment.
Professional Responsibility — Do The Right Thing
In Western culture, three professions are recognized. They are medicine, the law, and theology. The practitioners of these professions have long been accorded a special status in society in recognition of their special knowledge. The physician is expected to use his knowledge of healing only for good, and never to murder or maim a person. The lawyer is expected to give correct legal advice to his clients, to keep them free from legal entangle
My answer to that question would have been yes, and like all absolute answers, it would prove to be incorrect. An axiom in manufacturing is that the design engineer should not dictate manufacturing processes unless it is vital to the function of the design, metal vs. plastic, casting vs. forging etc. Once passed the gross requirements, dictating which machine tool to use would be beyond the design engineer’s prerogative unless there was a compelling reason! However, this should not be taken as t