If it's possible, 1

[WhyDoYouAsk]

how do I calculate how much force is necessary to prevent metal from expanding because of a temp. rise?

 

[GBor]

You calculate the thermal expansion of the material and the force required to deflect it back in to place.

Garland E. Borowski, PE
Engineering Manager
Star Aviation

 

[JohnBreen]

.......which is an application of Castigliano's second theorem – for displacements in a linearly elastic structure

Castigliano's method for calculating forces is an application of his first theorem, which states:

If the strain energy of an elastic structure can be expressed as a function of generalised displacement qi; then the partial derivative of the strain energy with respect to generalised displacement gives the generalised force Qi.

http://en.wikipedia.org/wiki/Castigliano's_method

John

 

[WhyDoYouAsk]

http://en.wikipedia.org/wiki/Castigliano's_method

Thanks, I'll pursue this.

 

[chicopee]

or you can use the easier familiar relationship to students of Strength of Material. Must assume a compact element.
S=E*e which can be in this other form
F/A=E*dl/L
S=compressive or tensile stress;E=modulus of eleasticity;e=strain;F=force; A=cross sectional area;dl= increase or decrease in length;L=original length before heating or cooling.

 

[GBor]

Hooke's law, I believe, since we are giving names to various formulae.

 

[WhyDoYouAsk]

Thanks, folks. . .
This last one I must have learned at some point.
I guess I didn't apply it to other than textbook problems, and by the time I needed for the real world, I forgot I knew it.
Or some such thing. . .?