The principle behind such construction is similar to suspension in vehicles. In places where earthquakes are common, such as Japan, buildings are constructed on special platforms that reduce acceleration and deceleration. Acceleration and SuspensionĪccounting for shock can prevent accidents during earthquakes if buildings are constructed to withstand it. The strong framework of this building is resistant to torsional forces generated by seismic events.
This is what makes a GPS-based data acquisition system so valuable: The lateral acceleration data contains an abundance of useful information that is becoming more important as more is understood of motorcycle dynamics.Transamerica Pyramid in San Francisco. For that, we must turn to a GPS-based system, which generates the acceleration channels from GPS data. A non-GPS-based system uses internal accelerometers to record these channels, and – as we will see in a following sections – this method does not work to record lateral acceleration for motorcycles. 80 g.īoth longitudinal and lateral acceleration are recorded by most data loggers. Which equals 25.8 ft/s 2, or we can convert that to. If the car can drive around the pad at a speed of 60 mph (88 ft/s), the lateral acceleration is calculated as: The typical layout has a radius of 300 feet. The usual convention is to label a right-hand turn as positive lateral acceleration, and a left-hand turn as negative.Ĭonsider the skidpad, a circular track used to test cars for how much lateral acceleration they are capable of. Note that the units of lateral acceleration are the same as longitudinal acceleration: m/s2 or ft/s2. Likewise, turn tighter and you will move away quicker. Visualize this as how quickly you are deviating from a straight-line path – at a higher speed you will move away from the straight path at a quicker rate. It is most commonly felt as an outward force (centrifugal force) when you are in a car that is turning a sharp corner, and is defined as: Lateral acceleration, or centripetal acceleration, may be less understood at times but is just as important a measure as its longitudinal counterpart. Using g makes the numbers more easily understandable and the units much less cumbersome to deal with. If we factor that into the results above, 20 mph/s converts to. That predictable rate is 9.8m/s2 or 32.2 ft/s2, and is referred to as 1g. If you drop an anvil from an airplane, it will accelerate at a predictable rate thanks to gravity. Now to factor in the acceleration due to gravity. Acceleration in a straight line is sometimes referred to as longitudinal acceleration or simply acceleration. The standard units of acceleration are ft/s2 (pronounced feet per second squared or feet per second per second) in imperial units, or m/s2 in metric. Note that braking is expressed as negative acceleration. Brake from 60 mph to 20 mph in 4 seconds and your acceleration is -10 mph/s. As the motorcycle speeds up or slows down, acceleration is defined as:įor example, if you accelerated from a stop to 60 mph in 3 seconds, your acceleration would be 20 mph/s (mph per second). The “G” part of the term stems from the usage of g, the acceleration due to gravity that is also used as a unit of acceleration – more on that later.Īcceleration in a straight line is well understood and visualized.
While in later sections we will discuss forces and take into account the weight of the motorcycle and rider, this section concentrates on the longitudinal and lateral acceleration channels. The usage is understandable given that force is related to acceleration through Newton’s second Law:īecause mass is a constant, force and acceleration are proportional – the force that we feel is directly related to the amount of acceleration being experienced.
As mentioned, the term G force is a misnomer and we are actually referring to acceleration.
0 kommentar(er)
