Tria/Tetra vs Quad/Hex

[izax1]

As a young engineer(some years ago now) I was told by my colleagues not to use Tria or Tetra elements, because they were not accurate enough. But today automated meshing is mostly with Trias and Tetras. Is it that we didn't knew better back then (I started with FE in the late 1980's and early 1990's) or has the elements improved? Or we don't care? What is your thinking?
Thankful for any views
Rgds

 

[rb1957]

avoid 3 node triangles (and 4 node tets). far preferred are 6 node triangles (and 10 node tets).

but all FEMs need some sort of validation these days.

 

[SWComposites]

3 node triangles are not good. 4 noded tets are very bad. avoid both.

auto meshers create triangles/tets because it is "easy". grrrrrr.

 

[rothers]

1st Order tris & tets are subject to shear locking. Rather than me waffle on here have a read at this excellent explanation:

https://fea-solutions.co.uk/shear-locking/