A study on the effects of a non-Newtonian speed breaker on vehicles and passengers

• Main Authors: Belarmino, Daniel Angelo L., Catindig, Alberto S., Jr., Santos, Jason Paulo T.
• Format: text
• Language: English
• Published: Animo Repository 2021
• Subjects: Speed bumps; Non-Newtonian fluids; Mechanical Engineering
• Online Access: https://animorepository.dlsu.edu.ph/etdb_mecheng/1; https://animorepository.dlsu.edu.ph/cgi/viewcontent.cgi?article=1000&context=etdb_mecheng
• Institution: De La Salle University

A speed bump is one of the many traffic calming measures to create a safe environment around the speed bump, usually around crossing areas for passengers. The main idea of the speed bump is that once a driver is to approach the speed bump the vehicle must slow down in order to avoid damage to the vehicle, and to avoid unnecessary passenger discomfort as traversing the speed bump at high speeds will cause a very sudden increase in vertical acceleration. However, while the speed bump does its purpose of forcing the vehicle to slow down as it approaches it, the speed bump is also known to cause damage to the underside of the vehicle, especially lower or lowered vehicles, even though the vehicle is already moving at slow speeds effectively “punishing” the driver despite slowing down. This is where the idea of a speed bump that is filled with a Non-Newtonian Fluid came into mind. A Non-Newtonian Fluid is a type of fluid that does not follow the Newtonian Law of Viscosity, wherein its viscosity is dependent on the stress it experiences causing it to either be more “liquid” in form or more “solid”. This “property” of the Non-Newtonian Fluid having a variable viscosity based on stress is desirable in the context of a speed bump that is able to deform based on the speed of the vehicle. The main idea behind the Non-Newtonian Fluid Speed Bump is that if a vehicle were to traverse it slowly, then the Non-Newtonian Fluid would act more like a fluid and “deform” around the shape of the vehicle thus eliminating the risk of damage to it, and when the vehicle were to travel at a high velocity, then the Non-Newtonian Speed bump would suddenly “harden” and become a solid effectively acting like a conventional Speed bump and that would then punish the speeding vehicle. To test the viability of the Non-Newtonian Speed Bump, it was tested via Simulation through CAD, and by testing a physical prototype of the Non-Newtonian Speed Bump. For both testing methods, the Non-Newtonian Speed Bump was compared to a concrete speed bump by having a tester on a bicycle go over the different speed bumps at varying speeds. The data collected from the testing were the vertical acceleration as the vehicle traversed the speed bump, the peak force experienced, and for the simulation testing the “average equivalent strain” and “average equivalent stress” were also recorded. Based on the results from the onsite experimentation, the Non-Newtonian Speed Bump performed about the same or better than the conventional concrete speed bump despite having almost double the ramp angle of the latter, and based on the simulation results, the vertical acceleration as well as the force reaction of the concrete speed bump showed a linear increase while the Non-Newtonian Speed Bump showed more of an exponential growth wherein at faster velocities, the wheel experiences a higher vertical acceleration and force reaction due to the Non-Newtonian Speed Bump solidifying. The results from both the onsite experimentation and the simulations suggest that the Non-Newtonian Speed Bump is a feasible concept that with further testing that could replace the conventional speed bumps made of concrete, due to the fact that as seen from the testing, the Non-Newtonian Speed Bump does deform as expected which would be able to reduce or completely eliminate the risk of damage to a vehicle as it traverses over the speed bump given that it is travelling at the correct speed.