Mechanical Engineering Load Calculations - Help!

[mechengr30]

Does anyone know of a great book or internet resource(s) to explain/describe mechanical engineering load calculations and give examples of how to perform load calculation tests?

I have been preforming load tests with weights and recording how much weight the product can hold and adding safety factor in. I don't know of an "intellectual" formula. I need to feed my brain more knowledge in this area. Any help would be greatly appreciated.

Thank you.

 

[lilliput1]

Are you talking about structural loads like beam bending, or column loads? If so you can start with a strength of materials textbook but remember all the concepts are theoretical, perfect world. Plane section remains plain, etc. Then you progress to the AISC handbook & find out the real world difference from the theoretical. Now you have to allow for slenderness ratios, and realize that plane sections do not remain plain, etc to define allowable stress. Note that AISC incorporates a safety factor in their allowable stress. I think the safety factor is 1.5 so allowable stress is 0.67 of the ultimate. So if you want an accurate true to life calculation estimate, you should follow AISC procedures & confirm by experiment that the unit will fail at 1.5 x the AISC calculated allowable stress.

 

[EnglishMuffin]

Lilliput1

It's "plane sections remain plane" not "plane sections remain plain" !

 

[lilliput1]

Yes plane, that's what I meant. Mechengr30 AISC also publishes a light gauge metal design book wherein they use the concept of effective width to calculate the stress of thin walled metal elements. Because of the geometry & thiness of the metal, portions are considered ineffective in resisting loads & treated as though they don't exist.

 

[chicopee]

Mechengr30, your question is too vague be more specific. It does not seem to me that you are referring to beam related problems.

 

[Tuck]

"Roark's Equations of Stress and Strain" should cover a number of complicated load applications. For general knowledge you will have to read or reread a Mechanics of Materials engineering textbook. You can take courses at the universty or community college level to refresh or introduce the subject.

 

[mechengr30]

I am not speaking of beam calculations. I am speaking of mechanical engineering concepts. Mechanical engineering covers a broad range of products. However, the materials used are typical....aluminum, steel, steel or zinc bolts, etc. I need a basic understanding of materials and a book which will define their material properties and what kinds of stresses and strains the material can withstand in various applications.

I certainly appreciate everyone's input. Hopefully, I have clarified my statements to get the answer(s) I seek. I will chekc out the books mentioned to see if that helps.

 

[chicopee]

Kent and Mark mechanical engineering handbooks have all the references that you will need, however, I also suggest that you get a text book on machine design.