Hello,

I’m doing a simple test on FLAC3D version 9 and 7. It consist of a slice (2D plane strain) of elastic cylindrical zones (tunnel lining) under gravity. V9 takes a lot of time to solve (for only 180 zones) and the mechanical ratios (local and average) reduce very slowly, which is different with V7. The data file and the plots are below. What is the reason for this ?

model new

model large-strain off

[rad_int = 4.92]

[rad_ext = 5.34]

[width_ = 2.0]

[zn_rv = 10]

[zn_or = 45]

[zs_or = math.pi*rad_ext / (2.*zn_or)

model gravity 0. 0. -9.81

zone create cylindrical-shell point 0 (0,0,0) point 1 (@rad_ext,0,0) …

point 2 (0,@width_,0) point 3 (0,0,@rad_ext) …

dim @rad_int ratio 1.0 size @zn_rv 1 @zn_or …

group ‘mat_=voussoirs’

zone reflect or 0. 0. 0. dip 90. d-d 90.

zone reflect or 0. 0. 0. dip 0. d-d 90.

zone cmodel assign elastic

;zone property dens 2.4e-3 young 35e3 poisson 0.2

zone property dens 2.4e3 young 35e9 poisson 0.2

zone gridpoint fix v-y range p-y 0.

zone gridpoint fix v-y range p-y [width_]

zone gridpoint fix v-z range p-x 0. tol [zs_or] p-z -1e3 0.

history interval 100

model history mechanical ratio-average

model history mechanical ratio-local

model solve ratio-local 1e-3 cyc 100 and