Steel railroad rails are laid in sections, each having a length
L = 12 m.
Assume that they are laid at a temperature of 20°C with a gap
of g = 4 mm.
- By how much can each section of length L expand before adjacent sections touch ?
- At what temperature would adjacent sections touch ?
- By how many degrees could the temperature increase further before
the thermal stress in the rails reaches 200 MPa (=stress limit for steel) ?
Assume : α=12.0μm/(moC) and E = 200 GPa