Calculation of 2D Aspect Ratio

tinh

Dear all,

I have one element (quad)

I check its aspect ratio by F10 panel is ~3.4 but when I check by quality index, it is ~4.2

What is wrong?

(settings: minsize => shortest edges, aspect => ideas)

Please help, if it is hm bug, was it fixed in HM2017?

 

the element:

Unable to find an attachment - read this blog

Sanjay Nainani_20973

Hello,

 

I downloaded your model and opened in HM2017. 

For me aspect ratio by F10 panel is 4.2 same as by quality index.

 

Thankyou

 

<?xml version="1.0" encoding="UTF-8"?>

tinh

Does anyone know how value 4.23 was calculated?

In hm help document, ideas aspect of quad is calculated by maxlength/{sqrt(2)*interior_circle_radius} ~3.4

 

Could you check if anything updated in HM2017?

 

Altair Forum User

Hi Tinh,

Yes, I noticed the difference. These values are different for F10 and quality index panel.

I'll check internally and will update you very soon.

 

Altair Forum User

Hello tinh,

Greetings!!!

 

I believe we are obtaining A/P ratio of 4.23 when the settings option is set to MINIMAL NORMALIZED HEIGHT in HM.

 

Source: https://www.engmorph.com/2d-element-aspect-ratio-diff-simula

<?xml version="1.0" encoding="UTF-8"?>

tinh

Thanks, but with minimal normalized height, my element must have aspect equal 5.39/1.18 = 4.56

and I am calculating aspect by ideas formulation which is not maxlength/minlength

Altair Forum User

Hi Tinh,

This is a bug which was reported and this issue will be fixed in the next update (2017.2.2).

tinh

Thanks George, do you know how to calculate value 4.23 as quality index panel? If there is an obvious formular, I can make a checking template easily.

Altair Forum User

Hi Tinh,

I think in this case it has taken ratio of the longest edge of an element to either its shortest edge (5.4/1.3=4.2), which is the Element Quality Calculation for HyperMesh.

 

 

<?xml version="1.0" encoding="UTF-8"?>