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The concept of Mechanical Resonance is fundamental when we speak about engineering, especially in the field of structures and mechanics. It's a phenomenon regarding the dynamic behaviour of a system (whatever you can think about).  What do we mean by "dynamic behaviour"? Simply, dynamic is what moves, the contrary of static, that is, standing, not moving. From a mathematical and physical point of view, a dynamic phenomenon changes during time, i.e, is described by equations in which time is a variable; instead, a static phenomenon doesn’t depend on time, is described by equations in which time doesn’t appear as a variable. If we take some pictures of a static phenomenon during the time, the pictures are all the same, nothing changed during the time. In reality, every system, although it seems to be static, it moves. Let consider, for example, a house: from a macroscopic point of view, a house is static, but in reality, its structure is continuously subjected to

Nowadays there is an increasing interest in innovative techniques used to inspect the internal part of materials to check if some flaws are present inside it, to have a quantitative measure of its mechanical properties. The main goal of these innovative techniques is to test the material without destroying it and for this reason these techniques are called non-destructive inspection techniques (NDT). Thermography is an NDT technique that allows detecting flaws inside a material by mean of observing it with a thermal camera. It is largely diffusing among industries and it's becoming a must in the quality checks and inspection phase. There are applications also in the medical field, for illness (like diabetes and vascular disorder) and tumour detection. In this article I will describe the working principle of thermography, providing some examples of real applications. How thermography works Thermography is based on the observation of a body using a thermal camera , exploiting

A thermal camera is an electronic device that allows transforming the infrared radiation emitted by any kind of body in a coloured image. Indeed, any body whose temperature is greater than 0 K (the absolute zero) emits radiation in the infrared spectrum. This is what we call heat . The infrared radiation is not visible to the human eye, so we need a particular device to visualize it. And here the thermal camera comes. But how does a thermal camera works? And how does it allow us to transform this infrared radiation, that is not visible, into a coloured image that we can see on a screen? Let see it more in detail. How a thermal camera works The scheme describing how a thermal camera works is the following: A sensitive element transforms the infrared radiation, namely, the heat emitted by a body into an electrical charge. This is possible also if the observed body is at a certain distance and really near to the thermal camera; This electrical charge is collected on an electron