failure phenomenon simulation by mps-dem geotechnical structure elastic behavior: mps failure: dem
TRANSCRIPT
Failure Phenomenon Simulation Failure Phenomenon Simulation by MPS-DEMby MPS-DEM
Geotechnical Structure
Elastic behavior: MPS
Failure: DEM
Strength Parameters
Tensile Strength for failure
Maximum Shear Strength (not failure)
2
ijnijijc tanmax
tnij c
ct
cij
ij
nij
Shear Stress
Normal Stress
Tensile Compression
Initial
1st parameter
ij
ct
cij New contact
2nd parameter
Coh_lij
Compression TestHomogenous Compressive Condition
Compression TestHomogenous Compressive Condition
Step-2 Compression1: constant x-stress
2: constant y-stress
3: enforced y-displacement, x-fix
4: x,y fix
Step-1 Confining Stress1: x-stress, 2: x-stress
3: y-stress, 4: y-fix
Confining Stress
25 kN/m2
4
3
1 2
10m
20m
4
3
1 2
x
y
3
Compression TestCompression Test
Type-2 formulation
4
Number of disconnected particles 0, 1, 2, 3, 4 more than 5
magnification ratio 5.0
• Failed particles appear on conjugate 45 degree line regularly
• Nonlinearity can not be observed in strain-stress relation, etc.,
It is known that the regular gird (lattice) alignment affect the failure behavior
JUMP
Macro Strain and StressStrain=disp. at top/lengthStress=force at top/wedth
Compression TestCompression TestRandom Model 1
Seed of random number 111113
5
Number of disconnected particle 0, 1, 2, more than 3
magnification ratio 5.0
Jump Jump
6
Number of disconnected particle 0, 1, 2, more than 3
Seed of random number 111112 6
Compression TestCompression TestRandom Model 2
magnification ratio 5.0
Compression TestCompression TestComparison of lattice model and
random model
7
Output Memo
8
Case 1 Big ModelConfining Pressure=50
1.5-3.0 seconds
Interaction condition
InteractionBlue :initial, orange:weakRed: Dem, green:mps
2.0秒間ではev2がメモリ不足Uper, lower layer=0.4m, Seed of random number=1111112
Acceleration (H)
Dev
iato
nic
Str
ess
Axial Strain