Roland's homepage

My random knot in the Web

Older articles (5/27)

  1. Resonance frequency of a composite tube

    Based on a question I ran into at work, I wanted to explore the influence of parameters like cross-section, wall thickness and laminate lay-up on the resonance frequency of a carbon fiber composite tube.

    The goal of this exercise is to determine which of the parameters are dominant.

  2. Using sed

    As I’ve written about before (see engineering), I often use CalculiX for structural mechanics calculations of products made from composites. These often involve calculating lots of different combinations of materials, lay-ups and load cases. For convenience and for them being self-contained, each variant is usually in a different directory.

    So when I find an improvement to e.g. a pre.fbd, Makefile or job.inp, I want modify all of the other instances as well. This is where sed (which stands for “stream editor”) comes into play.

    date: 2022-05-22
    modified: 2022-08-31
    reading time: 5 min.
    category: howto
    tags: sed
  3. Zero DSR power consumption

    Based on the data from the dashboard I’ve created a graph of the power consumption for a 2020 Zero DSR.

    As far as possible, this was measured on a level road at constant speed, on a good road surface and without much wind. The power is the product of the speed in km/h and the energy usage in Wh/km.

  4. Patching CalculiX Graphics to fix flipped screen hardcopy

    Since some time, I’ve had the problem that generating hardcopy images from cgx doesn’t work properly; the pictures are inverted vertically.

    At first, I thought this might have been a change in cgx. But comparing the source code for cgx.c for 2.16 up to and including 2.19, I don’t see anything that would explain it.


←  Page 4 Page 5 / 27 Page 6 →