143luvall
Mechanical
- Mar 29, 2006
- 1
Hi all
I am a relatively new user of Nastran. I am currently working on a fork assembly, which is used for engaging gears. The assembly consists of a fork and a shaft. A pin connects these two parts by press fit. An external load is applied on the fork. the contacts between pin-fork, pin-rail and shaft-fork are given using gap elements.
The press fit is simulated by giving an equivalent pressure on the inner surface of the pin.The model is meshed using tet elements.All the boundary conditions applied make sure any undesired motion of the pin.
These are the things I tried
1. Ran the Non-linear analysis of the model (tet4 elements) with just the pressfit with load factor of 0.001 - solution converged
2. Converted the tet4 elems to tet 10 with same load factor as in 1- solution did not converge
These are the convergence parameters I am getting
********
0ITERATION EUI EPI EWI LAMBDA DLMAG FACTOR E-FIRST E-FINAL NQNV NLS ENIC NDV MDV
45 9.8577E+01 1.8514E+09 1.6177E+09 6.3257E+02 6.0258E+01 6.2500E-02 -3.9435E+03 -7.5245E+01 1 4 2 1
***********
The model has 400,000 nodes and 4000 gap elements and computational resources are not a problem at all.
Any suggestions or information is greatly appreciated.
Thanks in advance,
Tom
I am a relatively new user of Nastran. I am currently working on a fork assembly, which is used for engaging gears. The assembly consists of a fork and a shaft. A pin connects these two parts by press fit. An external load is applied on the fork. the contacts between pin-fork, pin-rail and shaft-fork are given using gap elements.
The press fit is simulated by giving an equivalent pressure on the inner surface of the pin.The model is meshed using tet elements.All the boundary conditions applied make sure any undesired motion of the pin.
These are the things I tried
1. Ran the Non-linear analysis of the model (tet4 elements) with just the pressfit with load factor of 0.001 - solution converged
2. Converted the tet4 elems to tet 10 with same load factor as in 1- solution did not converge
These are the convergence parameters I am getting
********
0ITERATION EUI EPI EWI LAMBDA DLMAG FACTOR E-FIRST E-FINAL NQNV NLS ENIC NDV MDV
45 9.8577E+01 1.8514E+09 1.6177E+09 6.3257E+02 6.0258E+01 6.2500E-02 -3.9435E+03 -7.5245E+01 1 4 2 1
***********
The model has 400,000 nodes and 4000 gap elements and computational resources are not a problem at all.
Any suggestions or information is greatly appreciated.
Thanks in advance,
Tom
