Hello.

I am new to APDL. I am taking help from the documentation for modeling a simple beam.

I want to apply 10kN static load at midpoint, then unload it to zero. Then i want to run the harmonic analysis ( frequency range of 0 - 100Hz, 100 substeps).

I am finding warnings in the solution.

I am attaching my code file for the reference with the model picture.

I shall be thankful if you can guide me in using stepping in APDL commands if I am going in the right direction or not.

I would really appreciate your help in this regard.

The code for Boundary conditions and load steps is below

!_______________________Boundary Condition____________________

!left support

NSEL,S,LOC,Y, 0

NSEL,R,LOC,X, 25

D,All,UY,0

! right support

NSEL,S,LOC,Y, 0

NSEL,R,LOC,X, 395

D,All,UY,0

D,All,UX,0

!apply Gravity loads

esel,all

ACEL,,9810

!_______________Loading Steps_________________________________

TIME,1

NSUBST,5, 20, 1, on

OUTRES,ALL,1 ! WRITE ALL OUTPUT

Antype, static

NSEL,S,LOC,X, 210

NSEL,R,LOC,Y, 60

F,All,FY,-10000 ! applied load of 10kN

TIME ,2

NSUBST,5, 20, 1, on

OUTRES,ALL,1 ! WRITE ALL OUTPUT

Antype, static

NSEL,S,LOC,X, 210

NSEL,R,LOC,Y, 60

F,All,FY,0 ! Unloading of the applied load

Time, 3

Antype, harmic

NSEL,S,LOC,X, 210

NSEL,R,LOC,Y, 60

FK,ALL,FY,100 ! Apply force

HARFRQ,0,100, ! Frequency range

NSUBST,100, ! Number of frequency steps

KBC,1 ! Stepped loads

Solve

Finish

Thank you

~usman