UDF求教

fly100fly100

下面有一段UDF，是帮助文档上的：
DEFINE_SDOF_PROPERTIES(delta_missile, prop, dt, time, dtime)
{
prop[SDOF_MASS] = 907.185;
prop[SDOF_IXX] = 27.116;
prop[SDOF_IYY] = 488.094;
prop[SDOF_IZZ] = 488.094;
/* add injector forces, moments */
{
register real dfront = fabs (DT_CG (dt)[2] -
Release 12.0
c ANSYS, Inc. January 26, 2009 2-223
DEFINE Macros
(0.179832*DT_THETA (dt)[1]));
register real dback = fabs (DT_CG (dt)[2] +
(0.329184*DT_THETA (dt)[1]));
if (dfront <= 0.100584)
{
prop[SDOF_LOAD_F_Z] = 10676.0;
prop[SDOF_LOAD_M_Y] = -1920.0;
}
if (dback <= 0.100584)
{
prop[SDOF_LOAD_F_Z] += 42703.0;
prop[SDOF_LOAD_M_Y] += 14057.0;
}
}
printf ("\ndelta_missile: updated 6DOF properties");
}
哪位大侠帮我解答一下，上面的DT_CG (dt)[2]，DT_THETA (dt）分别是什么意思？文档里有定义的么？可以DT_OMEGA么？