Hi friends,

Here on the Structural Basics newsletter I always teach you how to calculate, design and verify structural members by hand - formula by formula - step-by-step.

This is important to learn structural engineering. You need to know the formulas.

But in reality, every structural engineer today uses software to design structural elements such as beams, columns, slabs, etc.

This saves us so much time, you can generate much nicer reports than with your paper hand calculations and (only when you know the formulas) you do much fewer mistakes. There are simply many design situations where it's not efficient or possible to calculate by hand. Calculating by hand the internal forces of a simply supported beam exposed to a line load is easy. But calculating the deflection of an inclined statically indeterminate roof rafter. Not so easy!

I am very happy and proud to share that ClearCalcs reached out to me to sponsor the Structural Basics newsletter. ClearCalcs is such a structural design software that structural engineers use.

As a Structural Basics reader, you also get a special deal. You get a 3-month free trial, instead of 1 month, if you sign up for a free trial by using the Structural Basics referral link: https://app.clearcalcs.com/?referralCode=2sGhr3a7c6rxKYhP&utm_source=structuralbasics&utm_medium=partnership&utm_campaign=newsletter-sponsorship​

I am very happy about this partnership, because I can finally show and teach you how to use structural design software.

In this newsletter, I’ll show you how to use the ClearCalcs beam calculator to calculate moments, shear forces and deflections. Based on these internal forces, we design structural elements like reinforced concrete beams, columns & frames in the coming weeks. First by hand, and then I'll also show you how to use the concrete beam and column calculators from ClearCalcs.

Let's get into it..

1. Sign-up and open the Beam Analysis Calculator

ClearCalcs is a web-based software, which makes it easier and faster to get started, because we don't need to install anything.

→ Sign up here and claim your 3-month free trial. ←

You can sign-up with your Google or Microsoft account. Or if you don't want that, just with your e-mail.

Next, open the Beam Analysis Calculator.

Once we are in the ClearCalcs project folder, click on Create a new project.

Now we fill out the project details (project name, project number, building standard → Eurocode for me) and click on Add a calculation. You can fill out a project address if you want. This is beneficial if you design exterior walls, or roof rafters, because ClearCalcs automatically calculates the wind and snow loads based on the project address. For now, I just selected the address of the football stadium I used to play in.

Next, we click on Beam Analysis.

2. Properties of the beam

First, we enter all the key properties of the beam such as bending stiffness, length, type and positions of the supports.

1. Section name: I just called the cross-section RC Beam 55x30cm, because that's the beam we use as an example in this tutorial. If we were to calculate a steel or timber beam, we could also import the material and cross-sectional properties by clicking on Link.

2. Bending stiffness EI: The bending stiffness is required for the calculation of internal forces and deflection of statically indeterminate structures. For a 55x30cm section and an E-modulus of 30000 MPa, the bending stiffness is EI = 124800 kNm2. We assume the cross-section is uncracked and we disregard the reinforcement.

3. Axial stiffness EA: Also required for the calculation of statically indeterminate structures.

4. Length of the beam: In this example, we'll use 16m =16000mm as the length.

5. Beam orientation: We select Horizontal. But you could also calculate the internal forces for inclined beams like roof rafters.

6. Supports: We have a 2-span continuous beam with 1 pinned and 2 roller supports. The first roller support is 8000mm away from the pin and the second is 16000mm away. We therefore have 2 8m spans. If you need to read up on supports and reaction forces, then check out this YouTube tutorial.

We could also add supports with a spring stiffness or continuous rigid/spring supports. But this is more advanced, which we don't need in 95% of all designs.

3. Loads

Next, we'll apply loads on the beam. ClearCalcs has many options for loads, like triangular loads, moments, axial loads, etc. In 95% of beam calculations, we only need line and point loads. So let's add them.

1. Name of the line load: I just called the line load p_d. Feel free to use a different name.

2. Start Magnitude w: This is the load value at the start location, which we have to set in 4. (Start Location). We use 30 kN/m as the design load on the beam.

3. End Magnitude w: This is the load value at the end location, which we have to set in 5. (Start Location). We use 30 kN/m as the design load on the beam.

4. Start Location x: This is the location on the beam, starting from the left, where the load value defined in 2. starts. We use a line load on the entire length of the beam. We therefore set 4. to 0.

5. End Location x: This is the location on the beam, starting from the left, where the load value defined in 3. ends. We use a line load on the entire length of the beam. We therefore set 5. to 16000 (16m away from the start of the beam).

6. Name of the point load: I just called the point load P_d. Feel free to use a different name.

7. Magnitude: This is the load value of the point load in kN. We set it to 60.

8. Location: This is the location where the load is applied as the distance from the start (0). We set it to 3000 which means that it's applied 3m away from the pin support.

We could also add axial or moment loads. You usually don't have these in horizontal beams in buildings. Or the axial loads are so little, that you can neglect them.

We now have inserted all the required inputs..

4. Results of the beam analysis

The calculation happens automatically. We instantly get the results like bending moment, shear forces, deflection, etc.

In ClearCalcs there are a few options to view the results.

Below the input sections, we get the results in table format in Per-Span Analysis and Per-Support Analysis.

1. Deflection in span 1: This is the max. deflection in span 1 between 0mm and 8000mm. In our case, it's 8.86mm.

2. Deflection in span 2: This is the max. deflection in span 2 between 8000mm and 16000mm. In our case, it's 4.21mm.

3. Moments in span 1: The positive and negative moments in span 1 due to the applied loads are documented here. In our example, the max. positive moment in span 1 is 233 kNm and the max. negative moment is -279 kNm.

4. Moments in span 2: The positive and negative moments in span 2 due to the applied loads are documented here. In our example, the max. positive moment in span 2 is 121 kNm and the max. negative moment is -279 kNm.

5. Internal forces and reaction forces: In this table, the internal forces at the supports are documented. Note that the moment in at the first support is also 0 kNm. For some reason, the software uses the bending moment from 0.012m away from the support. This is a small bug. But it doesn't really matter as long as you know how to interpret it!

And then there is also the summary on the right side of the interface. I personally prefer that way of result visualization. It has shear moment and deflection diagrams which are interactive. Simply click on one of the diagrams and the values are shown.

1. Biggest moment: This is the biggest moment in the beam due to the loads we applied to it. In our case, it's -279 kNm.

2. Biggest shear force: This is the biggest shear force in the beam. In our case, it's -177 kN.

3. Deflection: This is the biggest deflection in the beam. In our example, it's 8.86 mm.

4. Reaction forces: This visualization shows the reaction forces of the supports.

5. Shear force diagram: The shear force diagram shows the shear forces at every point of the beam. When you hover over it, it shows the exact value at the point your mouse is located.

6. Moment diagram: The moment diagram shows the moments at every point of the beam. As for the shear force diagram, try to hover over it to see the exact moment value.

7. Deflection diagram: The deflection diagram shows the deflection at every point of the beam. As for the shear force diagram, try to hover over it to see the exact deflection value.

8. Visualization of the loads: The last image is a summary of all applied loads.

5. Export as a PDF

As a structural engineer, you also need and want to document your calculations as PDF files.

And of course, we can also export the ClearCalcs calculations as a PDF. Simply click on the print button in the top right corner, select your Print Mode and Paper size of choice, and click on Export.

Final words

And voilà, you now have your first ClearCalcs calculation PDF, which you can attach to your Structural Design report.

We now calculated the internal forces such as bending moments and shear forces and deflection of a reinforced concrete beam. The next step is now to design and verify the reinforcement for these internal forces.

This is what we do next Wednesday. But with hand calculations again to understand what these structural design tools like ClearCalcs are doing.

Then in 2 weeks, we'll look at how to use ClearCalcs to verify reinforced concrete beams with software and all its advantages.

I hope you like these guides about how to use software in structural engineering.

Thank you, ClearCalcs, for sponsoring this episode of the Structural Basics newsletter.

See you next Wednesday.

Let’s design better structures together,

Laurin.

P.S.: In case you missed the ClearCalcs trial link, here’s another chance to claim your 3-month free trial and get started with structural design software today.