Help an EE student get into mechanical design

[Ryuk1990]

Hi, I'd like to learn some mechanical design. My knowledge in mechanics is mainly from general physics and a basic course in engineering mechanics. Is this enough to take on intermediate level mechanical design? Should I take a few ME classes? If so, what would you recommend? What is a good free software program for mechanical design? Any good books on self-teaching mechanical design?

 

[timthereaper]

Depends how far you've gone with engineering mechanics. I'm not sure what they cover in intermediate mech. design, but I think if you understand basic statics, mechanics of materials, some basic materials science, and are comfortable with combined loadings, I would say to take a shot at it. You might be able to pick some stuff up along the way even if you're not completely comfortable.

As far as designing structures, there is no manual to tell you what the best is. In my experience, it's all about understanding what loads are being applied at what points and finding out the load paths. Everything else is using your engineering intuition to make the structure handle those loads. FEA programs help engineers do this by computing where stress concentrations will happen in the modeled design, but then you have to come up with the way to handle that. There might be some constraints on the design too, like designing around components that will fit inside an enclosure, etc. and you have to take that into account in your design as well. Also, you might have to design in a factor of safety. If it's a critical component that might cause harm or injury, you might need to design it with a factor of safety of 3-4, meaning that the component should be able to handle 3-4 times the maximum load you think it will ever see. There's a lot to take into consideration, and sometimes you'll go through many different iterations on your design before you get something acceptable.

As far as free software, if you're a student, you might be able to get some free software from Autodesk at http://students.autodesk.com/. Their tools are pretty user-friendly and good for beginners.

 

[Jupiter6]

Hi, I'd like to learn some mechanical design. My knowledge in mechanics is mainly from general physics and a basic course in engineering mechanics. Is this enough to take on intermediate level mechanical design? Should I take a few ME classes? If so, what would you recommend? What is a good free software program for mechanical design? Any good books on self-teaching mechanical design?

Engineering mechanics generally encompasses statics and dynamics. You'd be wise to take a class in mechanics of solids (strength of materials) before tackling machine design just so you have an understanding of strength, toughness and stress-strain relationships.

To answer your question, the bible-like textbook on machine design is Shigley and Mischke's "Mechanical Engineering Design". Though the authors of that book do assume you have an understanding of what I mentioned above.