The railroad consisting of a rail supported on a spring pad, and sleepers which then rest on a spring (ballast) attached to the soil part. All spring are point to point springs, the wheel is suppose to run through the length of the rail but when even I run a job, there will be a large displacement of the rail, and the will falls off.
The file is attached here, I will be grateful if you help tell me what might be the cause or check through the file to see if my boundary condition is well defined. I intend applying velocity to the wheel but the issue at hand made me remove it. Thanks in anticipation
Hi Ogaga Ohwofasa,
Maybe derailing is imaginary and caused by large Deformation Scale Factor.
@ Victor J. Adlucky
Please what then is the solution to that? I ticked on the U1,U2,U3 check box for Rail and Wheel BC and the wheel did not go off but my model now looks rigid as there are no stress distribution in the whole model.
Thanks
It seems that there is some initial gap between the wheel and the rail, therefore the wheel vertical displacements become larger than the rail ones, and the wheel seems to derail during visualization with large deformation scale factor. Reduce it to see more realistic picture.
U2 shouldn't be ticked on In Rail and Wheel BC. Also, it seems that NLGEOM should be on for the step Moving.
I reduced the deformation scale and and on the NLGEOM for moving step, everything works fine just that the wheel did not move this time.
UR1 unchecked still not moving on the rail, is the problem from my step time?
Even the spring and dashpot between the rail/sleepers and sleepers/ground not compressing as a result of the wheel action. Is it because I did not add spring mass? I decided not to add any other mass other than that of the mass of the rail and sleepers.
Hello Ogaga Ohwofasa,
I'm sorry to reply you so late. After learning your model more carefully I have some remarks.
It seems that a mismatch of units takes place. The material properties use m (meters) and N (Newtons) whereas the lengths of parts are given in mm. But Abaqus treats them as m. Therefore, applied force is too low to ensure good contact between wheels and rails.
I send you cae file with some minimal changes, which allow wheels moving along the 1/4 length of the track. Now, the force is equal to 1.25E+10, which gives shortening of springs between rails and sleepers approximately by two times. If you’ll use probing, you can see that stresses are distributed to the soil through sleepers and springs, though values of these stresses are much more lower that in rails.
Regarding the deformation factor, it serves only for visualization, and its value 1.0 corresponds to real view.
Best regards.
Victor
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