Question

A coil spring with square and ground ends is to operate with a load that fluctuates between 90 and 180 lb

Answer 1

A coil spring with squared and ground ends is to operate with a load that fluctuates between 90 and 180 lb, during which the deflection is to vary by 1 in. We wish to use an available supply of steel spring wire having d = 0.200 in. and fatigue strength properties as shown in Figure 12.16 for shot-peened wire. Presetting and a clash allowance of are to be used. Residual stresses caused by presetting are not to be taken into account. They are considered to provide a sufficient safety factor that the possibility of higher stresses, should the spring close solid, can be ignored. Determine appropriate values for N, D, and Lf.

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