Fatigue Failure of Metallic Bolts

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 in: Industrial/Training Services

Preparing a Useful Engineering Report: Some Suggestions

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 in: Uncategorized

3D Printing (Additive Manufacturing) with Metals: A Brief Summary

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 in: Industrial/Training Services

In-Service Corrosion Monitoring: An Overview

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 in: Industrial/Training Services

Rolling Contact (Mechanical) Fatigue – RCF

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 in: Industrial/Training Services

Importance of the Term “Defect” from Legal and Engineering Perspectives

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 in: Uncategorized

Actions during Design to Mitigate In-Service Corrosion & Mechanical Failures – Part 2

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. […]

Posted in: Uncategorized

Actions during Design to Mitigate In-service Corrosion & Mechanical Failures – Part 1

Posted on June 16, 2014

The optimal time to make decisions and take actions to minimize potential failures of equipment, facilities and components is during their design. This two-part blog post provides an overview of the types of issues involved and specific actions that can be useful to the design engineer. Archived blog posts (at www.dmme-engineering.com) that discuss specifics are […]

Posted in: Uncategorized

Infrastructure and Corrosion – Part 3 – An Overview of Control Methods

Posted on May 1, 2014

There are several approaches to controlling corrosion of rebar in concrete and the associated damage. This is a summary of some of the more important techniques that are used. NOTE: Much of this brief overview was obtained from information in the valuable reference (*) cited below. Control of infrastructure damage due to rebar corrosion can […]

Posted in: Uncategorized

Infrastructure and Corroison – Part 2 – The Basic Concrete Deterioration Process

Posted on March 13, 2014

Infrastructure (in its multiple forms) may fail in different ways. However, the most common failure mechanism is likely the breakage of concrete that contains corroded steel, reinforcing bars (rebar). How does this occur? This blog post provides a brief summary of the process. Reinforcement is generally necessary in all concrete structures because concrete alone is […]

Posted in: Uncategorized