Establishing geostatic equilibrium when the initial stress state is unknown

Elements tested

CAX4P
CAX4PH
CAX4RP
CAX4RPH

CAX6MP
CAX6MPH

CAX8P
CAX8PH
CAX8RP
CAX8RPH

CAXA8P1
CAXA8RP1

COH2D4P
COH3D6P
COH3D8P
COHAX4P

CPE4P
CPE4PH
CPE4RP
CPE4RPH

CPE6MP
CPE6MPH

CPE8P
CPE8RP

C3D8P
C3D8PH
C3D8RP
C3D8RPH

C3D10MP
C3D10MPH

C3D20P
C3D20PH
C3D20RP
C3D20RPH

Features tested

Establishing geostatic equilibrium when the initial stress state is unknown is tested with various elements and materials.

Problem description

These tests verify the ability to establish geostatic equilibrium when the inital stress state is unknown for various combinations of materials and elements. Simple one-element tests are used in which pore pressure and distributed loads are applied.

Results and discussion

In all cases the results indicate that this option performs as expected. The absolute values of maximum displacements in all cases are within the limits specified. In addition, the results are close or identical to the results obtained without invoking automatic time incrementation, which is expected in these cases.

Input files

geo_nodisp_cax4p.inp: Elements CAX4P, CAX4RP, CAX4PH, and CAX4RPH with elastic and porous elastic materials; uniaxial compression; linearly varying pore pressure values prescribed.
geo_nodisp_cax6p.inp: Elements CAX6MP and CAX6MPH with elastic and porous elastic materials; uniaxial compression; linearly varying pore pressure values prescribed.
geo_nodisp_cax8p.inp: Elements CAX8P, CAX8RP, CAX8PH, and CAX8RPH with elastic and porous elastic materials; uniaxial compression; linearly varying pore pressure values prescribed.
geo_nodisp_caxa8p1.inp: Elements CAXA8P1 and CAXA8RP1 with elastic and porous materials; uniaxial compression; linearly varying pore pressure values prescribed.
geo_nodisp_coh2d.inp: Element COH2D4P with elastic material; uniaxial compression; linearly varying pore pressure values prescribed.
geo_nodisp_coh3d6p.inp: Element COH3D6P with elastic material; uniaxial compression; linearly varying pore pressure values prescribed.
geo_nodisp_coh3d8p.inp: Element COH3D8P with elastic material; uniaxial compression; linearly varying pore pressure values prescribed.
geo_nodisp_cohax4p.inp: Element COHAX4P with elastic material; uniaxial compression; linearly varying pore pressure values prescribed.
geo_nodisp_cpe4p.inp: Elements CPE4P, CPE4RP, CPE4PH, and CPE4RPH with elastic and porous elastic materials; uniaxial compression; linearly varying pore pressure values prescribed.
geo_nodisp_cpe4p_pla.inp: Elements CPE4P, CPE4RP, CPE4PH, and CPE4RPH with elastic material, extended Cam-clay plasticity model and Mohr-Coulomb model; uniaxial compression; zero pore pressure assigned at all nodes.
geo_nodisp_cpe4p_res.inp: Restart test for elements CPE4P, CPE4RP, CPE4PH, and CPE4RPH with elastic and porous elastic materials; uniaxial compression; linearly varying pore pressure values prescribed.
geo_nodisp_cpe6p.inp: Elements CPE6MP and CPE6MPH with elastic and porous elastic materials; uniaxial compression; linearly varying pore pressure values prescribed.
geo_nodisp_cpe8p.inp: Elements CPE8P, CPE8RP, CPE8PH, and CPE8RPH with elastic and porous elastic materials; uniaxial compression; linearly varying pore pressure values prescribed.
geo_nodisp_c3d8p.inp: Elements C3D8P, C3D8RP, C3D8PH, and C3D8RPH with elastic and porous elastic materials; uniaxial compression; linearly varying pore pressure values prescribed.
geo_nodisp_c3d10mp.inp: Elements C3D10MP and C3D10MPH with elastic and porous elastic materials; uniaxial compression; linearly varying pore pressure values prescribed.
geo_nodisp_c3d20p.inp: Elements C3D20P, C3D20RP, C3D20PH, and C3D20RPH with elastic and porous elastic materials; uniaxial compression; linearly varying pore pressure values prescribed.