In: Mechanical Engineering
A 4500 lb SUV is traveling at 65 mph when it strikes a staged attenuator designed to produce three different energy dissipation rates. For the first 6 ft, the attenuator produces a force of 20,000 lb on the impacting vehicle. The second stage is 4 ft long and produces a deceleration force of 40,000 lb. “How long does the attenuator’s 3rd stage have to be to safely stop the SUV if its deceleration force is 60,000 lb. Construct the a-s, a-t, and v-t curves for this impact. (Hint: safely stopping the SUV means the vehicle stops before using up the 3rd stage.)
Mass of the SUV = 4500 lb
Initial velocity = 65 mph = 95.30 ft/s
Take first stage data
Take data for 2 stage
Take data for 3 stage
The graph of acceleration and time is given below.
The graph of acceleration and distance is given below.
The graph of velocity and time is given below.