When different forces act on a structure, the outcome might not be obvious. The outcome can’t simply be left to guesswork or high likelihood because failing cannot be an option. Pressure applied on a structure can have a ripple effect across the entire system and through Finite Element Analysis (FEA) we can determine where stress accumulates and in return whether the structure will flex or bend, whether it will fail or break or whether it will hold strong and unaltered, and you don’t want your structure to fail or to break. Having the structure flex or bend, or keeping the structure unaltered, is essential. Both are good, but it depends on the context that you use them in. 

It is interesting to note that the most resilient of structures are actually the ones the bend. This flexibility allows to absorb the energy, rather than resist it. This flexibility reduces the risk of failure. If you think of a willow tree swaying in the wind, you see that it is adapting to, rather than resisting the wind - it is a case where the structure is flexing, or changing, in order to adapt and not snap. The same concept applies to car bumpers, as they absorb the impact, and change shape with collision, or with cables in a suspension bridge under load, or when the wing of an airplane is vibrating as it is working with the conditions and adapting its form. It is the ability to give a little when under pressure that will allow them to hold a lot. 

Having said that flexibility is not always the answer. There are some contexts where rigidity is key and here the structures must maintain their exact shape at all the time, no matter the stressors imposed. Some examples of these are support beams in a building, mounting brackets for heavy equipment or surgical tools. Even the minimal movement could lead to dangerous failure and not even the slightest of movement or flexibility is allowed here.

The two concepts are useful to increase the hold during stressors leading to higher resilience. However, one can’t thrive in the other’s environment. You can’t use mounting brackets’ material for the wings of airplanes, and on the other hand, you can’t use car bumpers’ material for support beams. 

This is the beauty of FEA.

With Finite Element Analysis, we can simulate how a structure will behave under specific physical conditions before anything is physically built. It works by dividing the design of the structure into small manageable elements, where this modelling technique will help us to predict how a material or a part of it, will respond to stressors, whether these are strains, vibration, heat, pressure and so on.

Let’s take earthquake-prone areas for example. In these settings, buildings and infrastructure must be strong enough to withstand dynamic forces while flexible enough to avoid cracking under sudden shifts. If the material is too rigid, then it can snap and break. If the material is too soft, it may collapse. There is a delicate balance which needs to be respected and that is the beauty that FEA can help us find. 

Using modelling techniques such as FEA supports smarter, safer and more sustainable designs. This is because whether the need is to stay perfectly rigid or flex under pressure - the methodology enables an understanding of the materials and structures long before they exist in the real world, therefore enabling more confidence in the safety of your structures.