# Question: problem 1 write the equation of undampened free torsional vibration...

###### Question details

Problem 1

Write the equation of undampened free torsional vibration and
find the corresponding natural frequency of oscillation for the 12
in. (rigid diaphragm) concrete slab supported on four 10”x18”
columns that is shown below. Columns may be assumed to be fixed
against rotation at top and bottom. Columns are 14 ft long. Neglect
self-weight of the columns and use a unit weight of 150
lb/ft^{3} for the slab. Use E = 4,000 ksi.