$u=v=w=0$ at node 1
$u=w=0$ at nodes 2, 11
$v=w=0$ at node 9
$w=0$ at nodes 10 23
The unit end force is replaced with the equivalent edge traction as $$l_x=\frac{-1}{0.02}=-50\text{ N/m},\quad l_y=0\text{ N/m},\quad l_z=0\text{ N/m}.$$
The initial stress matrix is then computed from the stress field obtained by the standard linear analysis.
The computation is executed with the following commands:
rmd3 beam61g1.i1 rpd3 beam61g1.i2 srh3 beam61g1.i3 fefs beam61g1.i4 geo3 beam61g1.iG heig beam61g1.iE stab beam61g1.iS
; NELEM NNOD ITED IP 4 23 61 ; CRIT SCALE THDEF RP 1.01 1 0.01 XY N 1:10 X 2*0 2*0.25 2*0.5 2*0.75 2*1 Y 5*(0 0.02) Z 10*0 EL E 1:4 N =A 1 2 4 3 =A =B 11 13 14 12 =B =2A =3B =4A =6B =6A =9B EN EN
; KREST IP 1 ; E α ν ρ MP 1 T 1 V 2e11 0 0.3 0 LV 1 T 9 V -50 0 0 ; Fx = -1 N AS 1 /M 1 /B 0 N 1 /B 0 C 1 3 N 2 11 ; left end /B 0 C 2 3 N 9 /B 0 C 3 N 10 23 ; right end /L 1 E 4 L3 EN EN
; KREST IP 1 EN EN
; KREST IP 1 EN EN
; ILC IP 1 EN EN
; KREST NROOT NITERX KTPR KEVP IP 1 1 0 0 1 EN EN
IP 1 EN EN
IP 1 EN EN LOADING PARAMETERS 0.329326E+04 * END OF STAB * TOTAL CPU: 00:00:00