engineering basics

[inthedark]

I am by no means an engineer. However I do design and make stuff off the cuff quite a bit, and usually make the parts pretty beefy to be on the safe side. However I have some items that I would like to scale down for size and weight reasons.

Where does one look for density and structural strength properties in metals? Also stuff like an applied amont of force before shear occurs?

Sorry, but I didn't know where else to post this question.

Thanks,
Kenny

[cadman]

matweb.com has the most complete info about all the properties you'll need to know about metals & plastics.

[wjbzone]

This is a good place for a lot if engineering fundamentals:

http://www.efunda.com/home.cfm

Bill

[NeoMoses]

If the parts you're making are subjected to repeated cyclic loading, you'll want to make sure you look at the design life for the part. Just because a part will hold the force/stress for a few cycles doesn't mean it will last for repeated cycles at the same stress level. A general rule of thumb: if the part is going to see less than 1000 cycles in its lifetime, you can just design it as if it were statically loaded. (always include some safety factor). If the part will see more than 1000 cycles in its intended life, you'll want to take a look at the stress concentrations and make sure it will last as long as you want it to.

[inthedark]

There is quite a bit to this information. Guess it's time for some research.

Thanks for the links and advice.

[ynneb]

There is software that you can use where you enter the type of material that is been used, all its dimentions including its wall thinkness, etc and how you are going to use it. It will then calculate its stresses. A friend was telling me about this, but unfortunately I can't remember what it was called. I will ask him and let you know.

[cadman]

Originally posted by ynneb
There is software that you can use....

Finite Element Analysis software, or FEA. These types of software are expensive and are designed for use by experienced engineers.

[inthedark]

The expensive highly technical apps are what I really don't want. At least not yet anyhow. I will keep an eye on this to see what others recommend as well.

Thanks everyone

[inthedark]

OK, I have done some homework.

Now the question is, "Do any of you know anyone that does FEA on a consulting basis?"

I have spoken to a few engineers, and FEA is quite a specialized field of work. The ones I spoke to would not consider doing any FEA consulting of any kind.

What a great law suit happy society we have become.

Thanks,
Kenny

[cadman]

Machine design and Design News are the two biggest magazines in the engineering field and you will probably find what you are looking for on their websites:

Machine Design
Design News

Desktop Engineering is another good magazine but I don't remember what their web address is.

[avsfan733]

doing very basic FEA in single parts is really not that hard, i mess with it already in optimizing parts...solidworks comes with whats called cosmosexpress which is the basic progrma, it can do most of the thigns your likely talking about and lets you insert your own materials properties or choose ones from a list. drop me an email if your interested and we can talk more

[bbarthurs]

I am a licensed professional engineer. Contact me bbarthurs@aol.com if you would like for me to take a look at your work.