Calculating average contact area

satri

Hello

I am trying to evaluate the average contact area when two particles contact each other.

I have defined a custom property called as contact area accumulator and a counter

but when i print out the values of the accumilated area it does not accumilate the value. I am using cuda api

In lines 1,2,3 the value in the first column should have got accumulated in the second column and also the value in the third column should have changed from 1,2,3…. like a counter.

Can anyone please tell me why this is happening?

satri

I have two particles only in my domain

satri

I do not understand this statement.

Does this mean if i do not reset the custom property then the value of custom property in the next time step will be accumilate of previous deltas. If not then its going to be wrong?

Stephen Cole

Hi,

Custom Properties have a Value and Delta, we can only modify the Delta with the API not the Value directly.

You can include Deltas in the model calculation and in the ConfigForTimeStep function which happens just once per time-step.

At the end of the time-step EDEM will sum all the Delta's and add them to the previous Value, so Value(t+1) = Sum(Delta(t)) + Value(t)

The statement is saying that if you want Value(t+1) to be equal to the sum of the new Delta's only and not include the previous value you have to include "-Value(t)" as a Delta as EDEM is going to add this.

For example if you have:

Value(t) = 10

Delta1(t) = 1

Delta2(2) = 2

If you don't add anything into ConfigForTimeStep sum of the delta's will be 3 and Value(t+1) = 13

If in ConfigForTimeStep you add another Delta

Delta3 = -Value(t) = -10

Then sum of the Delta's will be -7 and Value(t+1) = 3 (sum of original delta values)

satri

Ok so that means suppose I don't reset the property then in the next time step. And I make the ner delta equal to 1 in this step. Then it should keep getting accumulated right.

So why is it that the accumulated value is always 1 in the console image (column 3) according to the logic you mentioned above column 3 should be like a running counter. And column A should keep accumulating the contact area from different time steps. As value is previous value+ current delta.

Can you please explain why this is not happening. In the console as particles approach each other.