Fluid Structure Interaction in Abaqus

Few years ago I did several projects with a reputed canopy manufacturer from New Zealand. I’ve gotten the permission to share a video on Linkedin. In this post I want to expand a bit on the topic, prototype the post and show how ffmpeg can be used to fully edit the video.

Background

Performing analysis on these structures are hard. There is no real equilibrium other than what we refer to as “full flight”, where the drag and mass of the system is constant and in a steady-state configuration – which can take many seconds to achieve even from a “stable” initiation point as all effects try to cancel each other out.

Video Editing with FFMPEG

I want to concatenate these two videos without installing any 3rd party video-editing software. While FFMPEG is amazingly easy to encode and cut videos this requires more.

Converting videos, either as h.264 or webm:

ffmpeg -i xxxxx.mp4 -ss 00:02:01 -t 00:00:09 out. mp4 <- cuts and encodes

Concatenating videos; mylist.txt:
file video1.mp4
file video2.mp4
ffmpeg -f concat -safe 0 -i .\mylist.txt -c copy output.mp4

The result broke VideoLan.

If I first took the time to cutout snippets from this re-encoded video using webm format I could use the following command to stich it together.

ffmpeg -i .\video1.webm -i .\video2.webm -filter_complex "[0:v] [1:v]concat=n=2:v=1 [v]" -map "[v]" all.mp4

Even if this hurts hard when it comes to quality loss – I don’t care too much about it. It worked – and most importantly; I don’t want to spend any more time on it! It’s simply good enough.

Linkedin Post

How do you apply multiphysics in simulation today?

CFD and FEA must be coupled to accurately predict behavior of skydiving canopies. You won’t know how good you did without a proper test run!

#simulation #fsi #abaqus #techniasimulation #nza