Adam, Brian, Carmen and Jeff discuss theoretical and practical aspects of the design process, as well as the emotional states they experience when engaged in design activities.
Carmen is starting to gain confidence in his design abilities.
Jeff notes that a lot of his colleagues wanted to be design engineers, but the number of available positions for such work was rather limited.
Carmen and Jeff agree that the design process was not discussed in any great detail during their college years.
A wide variety of meanings have been attached to the word “design.” Additionally, the word can be used as either a verb or a noun.
A lot of design work goes on outside the realm of product design, notes Carmen.
Xerox PARC scientists decided that design activities “moved minds,” while engineering activities “moved atoms.”
In the Rational Design Model, constraints and objectives are known in advance, allowing optimal designs to be created in accordance with a predetermined plan that follows discrete stages.
In the Action-Centric Design Model, creativity and emotion guide design decisions along an improvised path in which no predetermined structure is evident.
Brian mentions using the Phase-Gate Model of project management in previous design work.
Young engineers are warned by Brian to avoid “custom firmware.”
Jeff mentions a video that attempts to explain the Engineering Design Process to children.
A discussion ensues about how often engineers see non-engineers as those who wanted to enter the engineering field, but couldn’t “cut it” as an engineer.
Jeff describes taking a DISC personality test early in his career, and discovering that individuals with strengths different than his weren’t really “broken,” as he had once believed.
The Dreyfus Model of skill acquisition is mentioned by Carmen.
Adam and Carmen describe developing professional confidence after working two or three years in their respective fields.
Adam mentions dealing with “the public,” and Brian notes such an experience is unfamiliar to most engineers.
If there was only one way to do everything, says Jeff, there would be no room for individual preference, and hence no way to offend one’s engineering sensibilities.
According to an Arup Group video, Ove Arup once said that “An engineer who doesn’t care a damn what his design looks like as long as it works and is cheap, who doesn’t care for elegance, neatness, order and simplicity for its own sake, it not a good engineer.”
A March 2014 Gizmodo article about “fish skeleton architecture” is referenced by Brian.
This episode of The Engineering Commons finds Adam, Brian and Jeff talking about steel, the most common of engineering metals.
Jeff and Brian consider whether comic book hero Superman should have been called the “Man of Osmium,” or the “Man of Molybdenum,” rather than the “Man of Steel.”
A key component in steel is carbon, which is alloyed with iron in percentages (by weight) from about 0.5 to around 4 percent.
Iron ore is rock that can be mined from the ground and processed to obtain fairly pure iron.
Once treated as a waste product, Taconite is now mined for its iron content, which is about 20 to 30 percent by weight.
The largest deposit of iron ore in the United States is the Mesabi Iron Range, located in the state of Minnesota.
Hematite is a type of iron ore that is reddish in color, and has a high iron content (between 55 and 70%).
According to at least one website, the “ite” suffix used in many geological and metallurgical names comes from the Greek word “lithos,” meaning rock or stone.
Coke is the primary fuel used in heating iron ore to a temperature where the iron melts and flows out of the blast furnace.
There are fourteen different metallic lattice structures found in nature, but the two most common are the Body-Centered Cubic (BCC) and the Face-Centered Cubic (FCC) arrangements.
Allotropy describes the capacity of certain elements to exist in two or more different phases while in a common physical state.
An alloy is the mixture of two or more metals, or the mixture of a metal with one or more additional elements.
At room temperature, iron exists in a BCC crystalline structure known as ferrite, or alpha iron.
When heated to a temperature between 912 and 1,394 °C, iron assumes a FCC crystal structure known as austenite.
Wrought iron is iron with a very low carbon content; this makes it easy to bend, form, and weld.
Low carbon steel is iron that has been alloyed with between 0.05 and 0.25% carbon (by weight). This is also known as “mild steel,” and is easily machined, formed, and welded.
Medium-carbon steel has a carbon content of between 0.3 and 0.6% by weight. The increased carbon content gives these steels greater hardness and wear resistance.
High-carbon steels have a carbon percentage of between 0.65 to 1%, giving such steels a very high surface hardness that makes them useful for cutting tools.
Cast iron has a carbon percentage of around 4%; this type of iron alloy is easily cast, but is rather brittle.
Rapid cooling of a heated material is known as quenching. The process of quenching a low-carbon steel heated to the austenite phase produces a very hard and skewed BCC crystal structure known as martensite.
Pearlite is a microstructure composed of alternating layers of ferrite and cementite.
Annealing is a heat treatment that reduces the number of crystalline dislocations, and thus increases a metal’s workability.
In contrast to annealing, tempering is a heat treatment used a remove some, but not all, of the hardness that has been intentionally introduced into a metal.
Adam notes that quenched steel can be very brittle.
Adam, Brian, Carmen and Jeff discuss theoretical and practical aspects of the design process, as well as the emotional states they experience when engaged in design activities.
