# Report a Bug

We hope you are enjoying our free online BMD calculator. This is only a new website, so there may be a few bugs on the site. Please help us by reporting these bugs below.

If you're reporting a bug, please let us know the situation you were trying to solve by supplying us with the following info:
• Beam Length
• Types of supports and their locations
• Point loads (magnitudes and locations)
• Moments (magnitudes and locations)
• Distributed loads (starting and ending magnitudes and positions)

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## 12 thoughts on “Report a Bug”

1. ***RESOLVED – 17 Sept 2013***
Getting an error in the BMD diagram at the point where I add a Moment.
The diagram shows the BMD curve in the opposite direction. Could you help on this.

• ***RESOLVED – 17 Sept 2013***
Thanks for the feedback Akshay. Very well spotted. You are correct – when a moment is added the BMD curve adds/subtracts a vertical line in the wrong direction. Thank you for picking up the error. This has now been fixed. Let us know if you spot anything else. Cheers

• Hi Paul,
I’m getting the results correct now. Thanks for considering the request and providing a quick solution on that.

Best Regards,
Akshay

2. Hi. Your equations and formulas tutorial doesn’t seem to have working links to the shear and bending moment equations. This would be really useful.

Thanks

• We will be finishing the tutorials and equations in the coming month or so. They will not be formulas based on the calculator, but rather generic formulas that can be applied to most questions you might get.

In the meantime, there are some sites out there that already teach the relevant formula for each beam type, so try searching them.

Hope this helps,
Sam

3. The calculator is unable to compute correct support reactions when you add a uniformly varying load across a beam.

Otherwise this calculator is AWESOME !

• Hey Amol, could you please specify under what conditions that you calculated it as being wrong? I tested it for a 10m beam simply supported with a 0-10kN/m distributed load that spans the full length of the beam. i.e a triangular distributed load. The reactions were correctly calculated as 16.67kN and 33.33kN. The working is as follows:

Resultant Force from Distributed Load = Fr = 10 x 10 x 0.5 = 50kN
This force acts at 6.6666m (2/3) from the first reaction.
Sum Moments at first reaction = 0 = 6.6666*-50 + By(10) –> By = 33.333
By + Ay = 50 kN
Therefore Ay = 50 – 33.33 = 16.67kN

Please let us know if this clears it up. Otherwise please send us the details of the incorrect values.

Sam

• If problems were to exist it would probably be due to the introduction of moments, as this area of the calculator wasn’t tested as much as the rest. The calculator has been used around 50,000 times so I wouldn’t expect such a fundamental error to occur. That’s not to say that there won’t be errors though! There might be errors because the calculator may not be able to handle some specific conditions which we have forgotten about. The purpose of this page was for people to find these errors so we could refine the code. There may also be graphical glitches/bugs with the shear force diagram (SFD), bending moment diagram (BMD) or free body diagram (FBD).

4. Hi I’m trying to use the calculator but my loads are only going +ve the -ve is not not working is it the same with all of you? I didn’t download the programme is that the reason why?

5. Only played around with one beam. Like the program.

1. The magnitude of a vector is positive. When I tried to put in a downward load, I needed to make the magnitude negative (in the input window). That is technically incorrect.
2. If a vector pointing down has a negative number next to it, some readers might misunderstand that to mean -15N down = 15 N up.

Suggested solution:
In the input window for a point load you might ask a user to select up or down (just like selecting one of the supports, by clicking on it), and then input the magnitude (truly as a positive number).

In the sketch, I would make the number positive. The direction of the load would be indicated by the arrow.

Haven’t checked but the same might apply to point moments and distributed loads.

Note: I might be interested in using this site to design fun problems for my students. That is why I’d like for the sketches to look as clear as possible

• Thank you very much Rainer. I’m actually surprised no one picked up on this earlier as you are absolutely correct! A downward pointing force with a negative label would indicate a positive force. I have made the changes and will update the program in the next couple of days. Thanks for your suggestion and glad to hear you are finding the calculator useful!