[Abaqus] User subroutine - Current values, values at the beginning and end of the increment, ...

Dear All,

I have some very basic questions for you.

We can read in Abq doc, at the pages of HETVAL User Subroutine:

<cite>

TEMP(1)

Current temperature.

TEMP(2)

Temperature increment.

TIME(1)

Step time at the end of the increment.

TIME(2)

Total time at the end of the increment.

DTIME

Time increment.

PREDEF(*)

An
array containing the values of all of the user-specified field
variables at this point (initial values at the beginning of the
analysis and current values during the analysis).

DPRED(*)

Array of increments of predefined field variables.

</cite>

and HETVAL

<cite>

can be used in conjunction with user subroutine USDFLD if it is desired to redefine any field variables before they are passed in; 

</cite>

Here are my questions:

1) What do they mean by "current temperature" and by "current values" of user/specified field variables? Is a current value, a value at the beginning (i.e. at TEMP(1)-DTIME) or t the end (i.e. at TEMP(1))of the increment?

 2) HETVAL is called after increment solution is calculated, isn`t it? I think so cause otherwise how it could know TEMP(2), i.e. increment solution.

3) Increments of predefined field variables are passed in HETVAL. I can redefine any field variables before they are passed in HETVAL by USDFLD. Does Abaqus calculate the filed increments automatically by redefinition of fields I do in USDFLD?

I know these are very basic concepts, so I would appreciate very much if someone could help me.

Regards,

alorenzom