An aluminum alloy specimen of .562" diameter and 2"gauge length was subjected to loads P, resulting in gauge lengths L as shown below. Fracture occurred at load 15,600 and maximum load applied was 1600 lbs. The diameters at maximum load and fracture were .505 and .483" respectively.
L = [2 2.0061 2.0093 2.0113 2.0132 2.0192 2.0233 2.0523 2.109 2.153]
P = [0 4000 8000 10,000 12,000 13,000 14,000 16,000 16,000 15,600]
What is engineering stress?