How does biasing work?

[baudencm]

All,

I need to know how abaqus calculates the spacing when it biases seeds/elements. I know the bias ratio is the ratio of the largest size to the smallest size. So it uses the total length of the segment and the number of elements you want to break it into and the bias ratio. Using those parameters how do you calculate the actual element sizes? Thanks!!

CB

 

[bfillery]

baudencm

I believe the each element size is a some constant product of the last. To work out the actual alogrithm, I suggest you do a simple biased mesh on a square, query the node locations in the direction corresponding to the bias and plot the results. This will give you a good idea if each element size is a some constant product of the last. The rest should be simple algebra.

bfillery

 

[baudencm]

Thanks for your reply. I have actually performed those steps. I believe the pattern is logarithmic somehow. If I put it on a log plot, then I get a straight line. I'm not sure how the slope of the line relates to the three given parameters.

 

[bfillery]

baudencm

If the bias ratio is B, and the number of elements is N, then the length ratio of element i+1 to element i = l_{i+1}/l_{i} = C = B^(1/N-1).

The element sizes, and therefore nodal spacing can be calculated from here.

bfillery