Hi Everyone. I am trying to model a cantilever beam which is fixed at one end and fluctuates at the other end. I want to write a UDF for the motion of the beam and also use dynamic mesh. Does anybody know how can I write the UDF? The beam does not deflect; just rigid body movement. I really appreciate if someone can help me.

What motion would you like? Is it just up and down oscillatory motion with constant amplitude and frequency?

thank you sham for quick reply. Yes, that is exactly what i need. One end of the beam is fixed and the other end just goes up and down with constant amplitude and frequency. Actually, I am beginner in writing UDF and don't know from where i should start writing UDF. thank you again.

Try to complie this.

#include "udf.h"

#define AA 1.0 //amplitude #define TT 2.0 //period #define OM (2.0*M_PI/TT) //angular frequency

DEFINE_CG_MOTION(updown,dt,vel,omega,time,dtime) {

vel[1] = AA*OM*cos(OM*time); // Y-velocity }

Hope it helps.

Sham.