an automobile suspension may be modeled as a 2-degree of freedom system with fre
ID: 2080873 • Letter: A
Question
an automobile suspension may be modeled as a 2-degree of freedom system with frequency response plot below.
based on the frequency response, how fast should you drive across the tracks in order that the body displacement is less than 10% of the wheel displacement?
An automobile suspension may be modeled as a 2-degree of freedom system with the frequency response plot illustrated in Figure 4. Specifically, Figure 4 is the gain in dB between displacement at the tire and displacement of the vehicle body supported by the suspension (that is, how much you move up and down when you hit a pot hole on a Michigan road). The rails of railroad tracks in the United States are 1.435 meters apart. Based on the frequency response plot, how fast should you drive across the tracks in order that the body displacement is less than 10% of the wheel displacement? Express your answer in miles per hour, recognizing that 1 m/s = 2.237 mph.Explanation / Answer
As per the description in the question,
Gain = displacement at vehicle body/dispalcement at tire
According to the requirement, Gin = 10% = 0.1
Gin (in dB) = ln(0.1) = -2.3dB
From the plot, gain of -2.3dB corresponds to approximtely 75Hz.
Speed of the vehicle required = distance/time = distance * frequency
Substituting the values, speed = 1.435 * 75 = 107.6m/s
Converting the speed into miles per hour,
1m/s = 2.237mph
107.6m/s in mph = 107.6 *2.237 = 240.76mph
Therefore, the vehicle needs to move at a minimum speed of 240.76mph to undergo only 10% body displacement.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.