Bending Moments Protecting our Moments

One of the most precious possessions people have on the planet aren’t physical possessions, but moments in time that live in our hearts. There are a lot of people to thank for making up these golden moments in our lifetimes. Have you ever thought about the ways structural engineers have paved the way for the moments in your life?  Even if you don’t know an engineer personally, I can assure you, they’ve been very much a part of creating moments in your life! Structural engineers are to thank for creating the moments that are protecting the moments we keep near and dear to our hearts. However, I am not talking about moments in time, I’m referring to what is known as “bending moments”  in structural engineering. Bending moments are an extremely important feature in engineering that affect our everyday lives. 

Bending Moments 

Let Me Explain…

In basic terms, a bending moment is a force (composed of a pair of internal forces) that act on an object that causes it to want to bend. For example, picture a diving board over a pool. When a diver stands or jumps on the end of the board, they create a bending moment with different magnitudes depending on the location of the force. Assuming structures are not being built to bend like diving boards; knowing about bending moments becomes critically important in the process of creating structures that are safe and sound. 

Additionally, there are quite a few elements that contribute to bending moments. These factors include movement, force, applied load, and behavior of the construction material. During the stressed state these elements are vital to the calculation of bending moments. According to SkyCiv, “A bending moment is a force normally measured in a force times length. In order to calculate the bending moment about a reference point, we take the magnitude of the force and multiply it by the distance of the force from the point.”  

It is crucial for designers and engineers to perform these calculations accurately. This ensures that excessive bending or breakage at any point of the structure does not occur. It is important to build durable, sustainable, and aesthetically pleasing structures. Even though a beam in a house may in fact be structurally sound, if it looks as if it is bending or unsafe to the eye, it is typically not going to be too comforting to the person walking under it!  When you put all of this into perspective, it shines a light on how complex a bending moment really is. 

The Right Material for the Right Job

 Picking the right material for the job is critical. Materials have different characteristics and morphologies: volume, weight, size, appearance, and resistance – just to name a few. Their use for a specific task depends on these characteristics and requirements. Stressful states can cause materials to morph. They have the ability or inability to assume stress (traction, compression, bending, torsion). Therefore, it is critical to select the right material because it will determine whether the structure will contort when forces are exerted due to the bending moment exceeding the resistance of the material. 

It is important to remember that engineers must verify the solidity, durability, and different characteristics of the materials to ensure the safety of the structure. If a portion of a structure cannot safely support the forces applied to it, this could create excessive deformations in the structure. Unfortunately, this could also cause it to become unsafe and even fall apart. 

 Impact of Loads

 The future use of a structure will determine the live loads being applied to it. In turn, this affects the support needed to hold the structure in place so that there is not enough bending moment to cause deflection. The solid materials (beams, slabs, columns) tend to be altered under the stress they are subjected to, from the application of the “load”. Thus, creating deformations due to the excessive force and bending moments. 

Additionally, loads can be classified as “point loads” and “distributed loads”. When applying the load at a particular point of the beam, a point load occurs. On the other hand, the distributed loads happen throughout a larger area. Making a cut helps decipher how the solid will react to the applied loads. In a beam, the necessary loads are applied to the section resulting from the cut. Consequently, determining the maximum bending moment. Understanding the location of the maximum bending moment, helps define the need for more support.

 Convex Vs. Concave Curvature

 The bending moment is changing depending on the internal reaction of the solid that has fluctuating stress. When this process generates stresses in the upper sectors of the solid, it is a negative moment that results in a “convex curvature”. On the other hand, if the bending moment causes tensions in the lower zones, it results in a positive moment that causes a “concave curvature”. Knowing how and where the moments are generating from can help the designer add beams to support the structure where need be. Therefore, this ensures the security and stability of the structure.

As stated by Eduardo Torroja, “In the bending state, the deformation of the whole piece is much more appreciable; everyone has experienced how a branch bends under the force of the wind or two bending moments that, with the hands, are applied at its ends”. 

 Bending Moment Diagram

 Part of the planning process is preparing for the stress that bending moments cause by creating a Bending Moment Diagram. A Bending Moment Diagram is the graphic representation of the alteration in magnitude of the occurrence. Calculating along the axis of a structural element. Thus, determining the transverse loads using the defined support conditions.

Information and Communication Technologies assist structural engineers with solving such diagrams. Currently, there are computer applications, programs and online calculators, which allow calculating the bending moment of a solid.

These determine the reactions in the supports, draw the diagram, and calculate the deviation. The cherry on top? In many cases these programs are free! On the other hand, upgraded paid versions are also available. You can view the complete calculations, showing the steps taken to calculate the diagrams.

Well-Deserved Shout-Out to the Engineers!

Imagine you are standing on your balcony watching the sunset and suddenly you feel the balcony slightly shift under your feet. Talk about ruining the perfect moment. This is why it is imperative that engineers take into account the bending moment of a structure. It ensures the safety of the public and the safety of your special moments. 

I bet you didn’t think engineers were to thank for so many of the “moments” in your life before, huh?! 😉 However, this is all thanks to the skilled engineers, like our brilliant team at Eastern Engineering Group. Engineers are the gatekeepers in protecting our golden personal moments and keeping them safe and sound. All attributed to the planning of the “bending moments” that are occurring all around us. With our engineer’s expertise, we are assured that the proper calculations will be done, the diagrams made, and the proper material selections will be chosen to ensure the safety of what’s truly the most precious in our lives – moments. 

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