Posted on October 30, 2018
Many in the recreational boating public are not aware of a serious type of accident that is neither rare nor without serious consequences. In these incidents the large outboard engine on a fast-moving boat strikes an underwater or floating object, breaks off the boat and flips into the passenger area while still running. The potential […]
Posted on March 31, 2018
Sometimes the physical properties of hardness and hardenability are confused. Hardness represents an existing condition after processing by heat treatment. It is a direct indicator of the mechanical strength of the steel. Hardenability denotes the potential of a steel to develop a particular value of hardness after a particular heat treatment. Hardenability is primarily dependent […]
Posted on February 6, 2018
Many considerations are included in a valid engineering design process. Typically decisions that provide for safe service and expected reliability in the given component or structure are the most critical. Determining the numerical value of an appropriate safety factor (or factor of safety) during design is vital to achieving mechanical or structural integrity. Incorrect specification […]
Posted on November 12, 2015
A common cause of failures in various types of equipment is fatigue failure of bolts that secure parts together. Fatigue in any type of dynamically loaded mechanical component accounts for more than 80% of all failures. This post reviews some important factors in fatigue failure of metallic bolts. Mechanical fatigue involves cyclic or fluctuating tensile […]
Posted on July 27, 2015
Engineers are excellent problem solvers. As writers of effective documents that communicate the results of our good work – not so much. This entry offers a few thoughts on how to improve the writing we do. I think most of us will acknowledge the value of the following points but they don’t always make it […]
Posted on March 30, 2015
“3D printing” or the more descriptive term – additive manufacturing (AM) – has received much publicity in recent years. What is this technology and what are some of its practical features? This blog is a summary of AM and its on-going development to make actual service components using metal alloys. Presented are selected portions of information provided in […]
Posted on January 29, 2015
Clearly it is advantageous to know when corrosion is occurring in operating equipment to avoid future failure. There is extensive literature on this topic. This post is a brief summary of information selected from the four references cited below. Each source includes several other references. It is useful to think about monitoring in two ways. […]
Posted on October 18, 2014
Often when engineers consider mechanical fatigue they envision cyclic, reversing stresses in a spinning shaft or possibly the up and down flex of aircraft wings. Rolling contact fatigue (RCF) or the associated mechanical wear is an important, closely related process to the traditional mechanism of fatigue but with distinct differences. RCF is also often known […]
Posted on September 1, 2014
This term raises some vital issues that the engineer should be aware of when using it. First several definitions are available and thus it is perceived differently by different groups and individuals. From a legal standpoint, in many states, using the term to describe a product that was involved in an incident involving an injury […]
Posted on July 22, 2014
This post provides more suggestions for potentially beneficial ideas to consider when designing for in-service reliability of various types of equipment. As stated in Part 1, most of the ideas are especially applicable to manufacturing or processing equipment that must function continuously over a long service life for the overall system to be economically viable. […]
