when I am reducing the load, result is similar.
But is kinda strange thing. One degree of freedom means that the mass can’t turn left or right. Newton’s law stay the same during motion.
It means that the motion is under bifurcation and *dynamic card is catching something else. Never saw it before.
*CLOAD,AMPLITUDE=StartAndStop
3,1,0.1
What about *MASS card? Is it working now for all methods?
** based on example spring1.inp
*NODE,NSET=NALL
1,0.,0.,0.
2,1.,0.,0.
*ELEMENT,TYPE=SPRINGA,ELSET=ESpring
1,1,2
*ELEMENT,TYPE=MASS,ELSET=Emass
2,2
*BOUNDARY
1,1,3,0
2,2,3,0
*DAMPING,STRUCTURAL=0
*SPRING,ELSET=Espring
10659.
*Mass, Elset=Emass
120
** amplitude, generated from spreadsheet
*INCLUDE, INPUT=graph.ods.inp
*step, nlgeom, inc=100000000
*dynamic
0.001,10.2,1.0E-08,2.0E-03
*CLOAD,AMPLITUDE=StartAndStop
2,1,1000
**Displacements
*node file
u
*endstep