1. Shown below is a picture of a Go-Kart which weighs 300# (with the rider), distributed with 60% of the weight on the rear axle and 40% on the front axle. The Go-Kart is powered by a gasoline engine that drives the rear axle via a chain drive and a 10” diameter sprocket. (Note: In chain drives, the loose side tension is assumed to be zero.) The rear axle supports the chassis on two bearings. The tires on the Go-Kart are 12” in diameter.
Suppose the Go-Kart wants to accelerate from 0 to 35MPH in ≤50 ft. If the tires don’t skid or spin, design the rear axle (i.e., specify dimensions) for a factor of safety ≥2.0 using the Von Mises criteria for static failure. To minimize weight and inertia, the axle should be made from a stock tube size and material rather than being solid (provide a reference for the size and material you select). The locations of the components on the rear axle are shown below.
2.Shown below is a traffic sign mounted to a pole. The pole is 4.50” OD x .237” wall thickness with Sut=70 ksi and Sy = 50 ksi. Other dimensions are shown below. You may assume that the vertical and horizontal portions of the pole have uniform dimensions with density = 0.3#/in3, E = 30×106 psi, G = 11.5×106 psi.
a. If the wind produces a load of 200# acting in the center of the sign, what is the factor of safety for the pole design based on the maximum shear stress failure criteria?
b. Using Castigliano’s method, determine the movement of the sign in the direction of the wind load.