Question

The main cable of a suspension bridge supports the deck with hangars spaced uniformly. Assuming the cable is weightless compared to the distributed load, the best approximation of its shape is a \(\underline{\hspace{2cm}}\).

• A. Catenary curve
• B. Circular arc
• C. Parabolic curve
• D. Hyperbolic curve

Hint:

A catenary describes a hanging cable under its own weight; a parabola describes a cable under a uniform horizontal load.

Answer 1

The Correct Option is C

When a cable carries only a uniformly distributed load (UDL) through vertical hangars and the cable's own weight is neglected, the load is uniform along the horizontal span. Under these loading conditions, the governing differential equation of the cable shape reduces to that of a parabola.
A catenary shape appears only when the cable's own weight is the dominant load, not when the load is transferred from the deck through hangars. Therefore, the correct approximation is a parabolic curve.
Final Answer: Parabolic curve