Older articles (7/26)

1. FEA with Calculix (1)

   This is the first part of a series of articles where I hope to show how to analyze deflection and stress in structures using the free CalculiX software. I’m using version 2.17. The focus will be on sandwich structures because that is the area in which I’m most interested. Compared to parts consisting out of a single material this is a bit more tricky as we will see in this article. The main reason for using finite element analysis (“FEA”) in general is that it allows for complete analysis of problems where no integral solution exists.

   Additionally, some of the assumptions used in Euler–Bernoulli beam theory for analyzing deformation and stresses in beams and plates do not hold for sandwiches.

2. Why I think engineers should be programmers

   During my engineering education and the start of my career, a lot of design and drafting work was still done on paper. During that time I also discovered computers, and how they could be an extra tool in my toolbox.

3. Engineering category

   Although my training and career has been in mechanical engineering, there is not much about that on these pages. In this new category, I hope to remedy that.

4. Opening vim in a new terminal

   By default, when you open vim it runs on the current terminal. When running X11, I want to start it in a new terminal.

5. Buildworld benchmark on my new workstation

   As a real-world benchmark I rebuilt the FreeBSD OS after the most recent published vulnerabilities.

6. Writing speed on FreeBSD 12.1-STABLE amd64

   This is a repeat of the tests I ran in 2010 and 2012, on my current hardware.

   The test is …

7. Playing a sound when the battery is low

   Although I have a battery indicator on the bottom of my laptop screen I don’t alway check that often enough. That’s why I wanted to add an extra warning in the form of an audio signal. So even if I’m turned away from the laptop, it should still catch my attention.

8. Xinput settings for Kensington Expert Mouse

   Detecting possible parameters.

   > xinput --list-props 13
   Device 'Kensington Kensington Expert Mouse':
       Device Enabled (138):  1
       Coordinate Transformation Matrix (139):        1 …

9. Xinput settings for Synaptics TouchPad

   Detecting possible parameters. Updated for “styx”, a Lenovo ideapad 5

   styx:~> xinput --list-props 11
   Device 'MSFT0001:00 04F3:3140 TouchPad …

10. Cleaning up old port configurations

    On FreeBSD, ports save their configuration parameters under /var/db/ports. When you de-install a port, this configuration remains behind. This is how to clean old configurations up.