The maximum normal stress equals the stress concentration factor multiplied by the nominal stress in the region of the minimum cross-sectional area. Set the maximum normal stress equal to the maximum allowable normal stress in the part and find the corresponding value of the stress concentration factor, K. Determine the stress concentration factor for stresses in the region of the shoulder fillets with radius r.

An external consultant recommends that a plant installs a bank of capacitors for power factor correction. this will reduce the peak electrical demand charges by an average of 93 kw every month. the plant current pays $13 per kw in peak demand charges. the capacitor bank will include 223 kw of fixed capacitors, and 183 of variable capacitors. the fixed capacitors cost $59 per kw, and the variable capacitors will cost $65 per kw. the consultant charges 21% of the equipment costs to install the capacitors. because this project will reduce the demand for the electric utility, they are prepared to provide a one-time rebate of $42 per kw of reduced demand. what is the simple payback period for this project (in years)?