# Mechanical problem related to materials

1. Jun 5, 2009

### racer

1. The problem statement, all variables and given/known data

Use calculations to determine what could happen to the 215mm wide glass window if it is tightly fitted into teh aluminum frame.

The temperature in the mechanical wrokshop was 20 C
The Maximum temperature in Bahrain = 55 C
THe Minimum temperature in Bahrain = 5 C
Thermal Expansion Alluminum = 24x10-6/K
Thermal Expansion Glass = 9x10-6/K

2- Calculate the weight ( grams ) of the glass window.
Use a glass size of 215mm * 155mm * 2.8mm

2. Relevant equations

No relevant equation

3. The attempt at a solution
I was not given any equation or any hint about how to solve it on purpose to make me research, I tried to search about an equation that I can plug these values in or anything related, the closest I got was with tensile stress but I have not found anything useful, I do not need someone to solve it for me, I need to know how to solve it and by what equation.

Thank you so much

2. Jun 6, 2009

### nvn

racer: The PF rules state we are not allowed to tell you how to solve your assignment. A large part of the learning process is to read and study your text book enough to find and list some relevant equations yourself. Keep trying; list some relevant equations. And you must show your work; then someone might check your math.

Hint: Look up the density of your glass. Look for an equation relating temperature and strain, using coefficient of thermal expansion. Look for an equation relating stress and strain. Look for the tensile and compressive strength properties of your glass and aluminum materials.

You did not list the cross-sectional dimensions of your aluminum frame yet. Generally, I think window frames probably do not grip the glass rigidly enough to put the glass in significant tension (maybe I'm wrong). Therefore, you could probably just work the problem for compressive stress on the glass. But you could work it for tensile stress on the glass, also, if you wish.