Comments on: Advantages and disadvantages of other materials compared to steel ?

Question: Advantages and disadvantages of other materials compared to steel ?

vincentm — Tue, 26 Sep 2006 08:13:18 -0800

What are the main advantages and disadvantages of materials like glass, concrete, wood, and plastics, compared to steel ?

I have to build a small training course about the use of materials (in construction and manufacturing) and their advantages and disadvantages (resistance to heat, price, easyness of forming,etc.) in comparison to steel (carbon or stainless steel).

I found several documents but it is often too technical and detailled. If someone can give any nice web resources on this topic it would be nice.

By: Pastabagel

Pastabagel — Tue, 26 Sep 2006 08:25:42 -0800

There are material data sheets for most materials including wood, plastic, glass, steel and composites, but they are probably way too technical.

Here is an article comparing steel and concrete for construction. And some cost comparisons here.

I can't really find a single site, because this question is sort of unfocused, could you be more specific about how you want to present it?

By: chrisamiller

chrisamiller — Tue, 26 Sep 2006 09:01:33 -0800

Manufacturing of what? Obviously, we don't want football helmets and shoulder pads made out of steel, and I don't want my car's frame made out of plastic. You'll probably have to be more specific to get any kind of reasonable answer.

By: vincentm

vincentm — Tue, 26 Sep 2006 09:02:54 -0800

I'm not necessarily searching for graphics or visual things as I have a team of graphic designer who can work on that later. The second link who found suits me well.

Ideally it would be nice to have the same comparison with plastics, glass, wood, etc.

By: fake

fake — Tue, 26 Sep 2006 09:04:58 -0800

the main advantages and disadvantages of materials depend entirely on the object you intend to manufacture.

By: vincentm

vincentm — Tue, 26 Sep 2006 09:05:06 -0800

> Chrisamiller. I would like to focus more especifically on :
- car parts (a comparison with aluminium would be great)
- food packaging
- construction (structure beams,etc.)

By: b1tr0t

b1tr0t — Tue, 26 Sep 2006 09:08:12 -0800

I am not a civil enginerr, nor a materials engineer, but off the top of my head:

Glass:
*Pros: transparent, can be coated to block specific wavelengths of light or to resist damage
*Cons: shatters easily when stresed

Concrete:
*Pros: Extremely strong in compression, can be poured into a form on-site, or pre-fabricated. Can be poured and cured under water, if necessary
*Cons: Very weak under tension, though this can be moderated with steel reinforcement

Wood
*Pros: easy to shape and work with hand tools, can be "bent" to fit
*Cons: burns easily, can be infested by insects

Plastics
*Pros: extremely wide array of available plastics with characterists ranging from soft to brittle
*Cons: most plastics have low resistance to heat, generally toxic when burned

Steel
*Pros: strong in both compression and tension. Can be used to augment glass and concrete structures (most modern buildings are largely a combination of concrete, steel, and glasS), hardness can be adjusted by changing the carbon content at fabrication
*Cons: Similar strength can be found in much lighter (though much more expensive) composite materials

By: RustyBrooks

RustyBrooks — Tue, 26 Sep 2006 09:21:30 -0800

This is one of the strangest questions I've seen in a while, and that's saying a lot.

You need to create a training session for something you know nothing about? You mark as a best answer some exceptionally well known things about what you need more information on? You want to "focus" on 3 *completely* different areas of design?

Which is better for food packaging: steel, concrete or glass, wood or plastic. Hmm. Let's make us some nice glass structure beams for construction or perhaps some wooden car parts.

By: b1tr0t

b1tr0t — Tue, 26 Sep 2006 09:34:14 -0800

wooden car parts

By: Pastabagel

Pastabagel — Tue, 26 Sep 2006 09:36:17 -0800

What Rusty Brooks said. Did b1trot really tell you something you didn't know? I thought most of that stuff was common knowledge.

Also what he wrote about plastic isn't technically correct. Plastics do resist heat, which is why they melt and why they make such great insulators, like for coolers. Same with wood. PVC plastic pipe is commonly used to carry hot water in residential and commercial plumbing, and nearly all cookware is coated in plastic (teflon). Cooking utensils are often made of plastic for example.

They do resist heat, but they don't conduct it. Steel is a great heat conductor, which is why steel cookware gets burning hot, but the wooden cooking spoon you leave in the boiling water doesn't. One conducts the heat (and moves it to something else, the other resists it, and burns/melts/cracks.

By: LionIndex

LionIndex — Tue, 26 Sep 2006 09:50:38 -0800

glass structure beams for construction

By: vincentm

vincentm — Tue, 26 Sep 2006 10:07:23 -0800

Of course, what b1tr0t said is common knowledge but obviously it fuelled discussion and help me gather some ideas (a sort of virtual brainstorming).

By: Skorgu

Skorgu — Tue, 26 Sep 2006 10:11:09 -0800

Possibly related, there is a fascinating article in this week's Economist about new technologies and uses for concrete. Apparently, concrete can now be made conductive or translucent by adding different fibers to the mix. This doesn't affect the inherent structural properties of the material but it does open up new avenues for use.

By: JJ86

JJ86 — Tue, 26 Sep 2006 10:38:28 -0800

Any material has advantages and disadvantages depending on their purpose. So without a purpose in mind, the transparency of glass can be an advantage or a disadvantage. The malleability of steel can be an advantage or a disadvantage. I think the question people are wondering is how to make a comparison about disadvantages without knowing what the criteria of comparisons are?

From a building structural standpoint steel has the advantage of bending without breaking but obviously not all structural elements require or even want those criteria. In seismic zones you may want a structural flexibility whereas in a hurricane zone you do not. I would say you should structure the question about the advantages of materials for specific purposes. For example which is the best material to build a structure use in a hot, sunny climate?

By: jamjam

jamjam — Tue, 26 Sep 2006 10:42:50 -0800

That's an amazing structure, Lionindex; I suppose such a thing would only be conceivable in a milieu in which the possibility of vandalism didn't so much as cross the designer's mind.

Pastabagel, I would say teflon coatings are on less than 25% of the new and used cookware I see here in the US. Your ideas about conducting and resisting heat, and the consequences thereof, appear to be eccentric, at the very least; are you perhaps using 'resists' in the sense of electrical resistance rather than the sense of 'is not broken down by moderate to high levels of heat' which seems to be more appropriate here?

By: Pastabagel

Pastabagel — Tue, 26 Sep 2006 11:10:42 -0800

jamjam, that is how I'm using it, yes, because it establishes a better opposite, conducts, which makes talking about it easier. Really, it's about heat transfer. That which trasfers heat better, breaks down (burns, melts, etc) less. Force of habit to think about it in those terms, sorry.

Metal transfers heat better than wood (conducts), which is why a heated metal feels hot, it's transferring the heat through itself to you. Wood doesn't transfer (resists the passage of heat therethrough), so it feels cool on the end you hold while the other end heats up until it chars or burns.

Glass is very interesting, because it can be made to do whatever you want because so many crystal structures exhibit the transparent property we associate with glass. Pyrex is glass, and can tolerate tremendous heat befopre breaking, but ordinary drinking glasses can't, and could shatter if you put ice water into them fresh out of the dishwasher. Same with plastic, you can't make it do almost anything you want, provided you can pay for it.

By: jannw

jannw — Tue, 26 Sep 2006 14:11:14 -0800

pick a practical task and apply the materials to the problem ... in a practical way ... pros and cons ... which are generally easy to find in a "amateur" paper

eg. Boats in wood, steel, aluminium, fiberglass OR aircraft in wood, steel, fiberglass,

why use one material over another? ... why not one material at all?

By: b1tr0t

b1tr0t — Tue, 26 Sep 2006 14:33:56 -0800

Don't forget Concrete Boats.

Sadly, it appears no one has built a (flying) concrete airplane yet.

By: jannw

jannw — Tue, 26 Sep 2006 14:39:58 -0800

forgot ... twas actually an important point ... concrete boats as an alternative option ... almost bought one myself ... and lots were built in the 70's ... they don't rust, get worms, or "GRP cancer" ... but they are concrete boats Uugh ... still some have placed well in racing many years ago (to the best of my memory)

By: yarmond

yarmond — Tue, 26 Sep 2006 17:09:28 -0800

One thing you might try including are some Material Selection Charts, which can give quick estimates of material properties for various material classes. They also show how different material properties are related and what sorts of compromises are involved in selecting one material over another. There are books with a better variety of these charts.

Also, I feel the need to point out that Pastabagel's interpretation of thermal resistance is wrong. Thermal conductivity and melting point are two distinct and generally unrelated physical properties.

By: phliar

phliar — Tue, 26 Sep 2006 19:48:27 -0800

You have to read The New Science of Strong Materials by J. E. Gordon. He goes into some depth about why things have the strength they do, and why materials are so much weaker than inter-atomic forces.

A very easy to read introduction to materials science. Gordon is one of the orginal fiber-reinforced plastics guys.

By: vincentm

vincentm — Tue, 26 Sep 2006 23:58:35 -0800

I didn't execpt some much for my (not so precise I admit...) question. Thank you everybody.