[Geoqus] On Transient analysis of Soft material

[bsaad at po-box.mcgill.ca]

dear manooch and all
My material  is soft plastic with isotropic hardening curve

pressure (pa)   Volumetric Strain

500	         0
2000	      0.0660498
4000	      0.0990747
10000	      0.142731
20000	      0.175756
50000	      0.219413
100000	      0.252438

I analyze it under large deformation trying both quadratic and linear . 
The job reaches to a point where the time increment becomes 1E-08 and 
then aborted giving message? 8 negative eigenvalues , Excessive 
distortion of 176 integration points? . Any modeling recommendation on 
how treating this issue is appreciated

P.S I am using Cam Clay modeled that is recommended to model my 
geologic non-cohesive material under consolidation (transient) analysis
, 2D plans strain, element CPE8P
Bassam