Classic rail vehicles have rigid wheelsets: both wheels are interlocked and have the same degrees of freedom (DoF), so they share all their displacements. They also have positive conicity, this is, the wheel surface on the contact patch is conical and, if we extend these ideal cones, their base would meet at the centre of […]
The locomotion of every moving system, alive or manufactured, is produced by the interaction between some movable components or appendages and the surrounding environment. This applies for every kind of surroundings: land, water or air. For water and air, Navier-Stokes equations allow predicting the interaction with the fluid with very high precision. In the case […]
Maples rely on wind, upward currents, and gusts to spread their seeds over long distances that can reach several kilometers. Maple seeds are able to autorotate because their center of gravity, determined by the position of the nut, is located at the base of the wing-shaped seed. It has been observed that, despite their small […]
Unlike road vehicles, all rail vehicles run through exactly the same piece of track and they cannot drift away to avoid a bad quality rail. Moreover, the contact patch between wheel and rail is a steel-to-steel contact with a small area and huge loads, so the stress the material is subject to is extremely high […]
If you have ever faced that thankless task of cleaning fish, for sure you will have realized, at least envisaged, the complex architecture of the fish’s natural armour. Fish scales play the role of a skeleton which provides both protection and flexibility at the same time. It goes without saying that this fact has not […]
Humans can build and use the most sophisticated tools. One of the reasons is the configuration of our hands, which enable us to hold items in a very convenient way. But further than that, we can actually grab items because of the friction coefficient that exists between the skin of our hands and the surface […]
High speed trains are the best example of vehicles that, although operating at somehow extreme conditions, are very comfortable. And by comfort I mean that the vibration level that passengers feel is relatively low. The components that allow this level of comfort are the pneumatic springs, torus-shaped rubber elements filled with pressured air. Their behaviour […]
Scientists have always peaked into nature in order to mimic its most interesting features into industrial processes. This adaptation process is called biomimicry, and the most recurring example is the history of how the Swiss engineer George de Mestral invented fabric hook-and-loop fasteners (Velcro) in the 1950s, after he saw how burdock seeds got attached […]