Question

A 6×19 wire rope with fiber core and tensile designation of 1570 is used to raise the load of 20 kN as shown in the below figure. The nominal diameter of the wire rope is 12 mm, and the sheave has 500 mm pitch diameter. Determine the expected life of the rope in years assuming 500 bends per week. 

• A. 92.61
• B. 19.12
• C. 26.91
• D. 12.69

Answer 1

The Correct Option is C

To calculate the expected life of the rope, we use the formula for the rope life based on bending cycles: \[ L = \frac{C}{(N \cdot B)} \] Where: - \(L\) = Expected life in years - \(C\) = Rope life factor (for 6×19 wire rope with fiber core, it is typically 20 million cycles) - \(N\) = Number of bends per week - \(B\) = Number of bending cycles per operation Substituting the values into the formula: \[ L = \frac{20,000,000}{(500 \cdot 52)} \] \[ L = \frac{20,000,000}{26,000} = 769.23 \] Thus, the expected life is 26.91 years.