I am using a VUMAT (vumatXtrArg) to extract the element and material point numbering from Abaqus and I am getting some "interesting" results. For a fully integrated (hex) element; say with 2 elements; I would expect something as follows:

ELEM_idx; MP_idx

1;1

1;2

1;3

1;4

1;5

1;6

1;7

1;8

2;1

2;2

2;3

2;4

2;5

2;6

2;7

2;8

Instead, there are repeating indices, such that you end up with non-unique ELEM_idx and MP_idx pairs...

1;1

1;2

1;3

1;4

1;5

1;6

1;7

1;8

2;1

2;1

2;1

2;1

2;1

2;1

2;1

2;1

It seems also to be influenced by the number of CPUs used to call the job. Ultimately, I need to assign properties within my user material depending on the material point ID, and if this is non-unique, it obviously makes things quite difficult...