PFC6.0-FLAC3D柔性膜常规三轴排水实验

通过PFC6.0和FLAC耦合来模拟柔性膜，需要注意的是，这里不是预压围压后移除墙边界，再加柔性膜。

而是直接生成柔性膜，给柔性膜施加预压和围压，更符合实际。

加载后的效果：

应力应变，密砂到达峰值后应变软化：

体应变，密砂先剪缩再剪胀，后趋于稳定：

1. 成样

model new

def para_set

;;==========bondary condition======

rad = 0.025

height = 0.10

poros = 0.42

segments = 12

Density =2650

b_rad = 0.001

freeRegion = height/2.0

;;==========contact patameter========

emod = 1.0e8

fric = 0.5

rr_fric = 0.4

end

@para_set

model random 10001

;domain setting

model domain extent [-rad*2] [rad*2] [-rad*2] [rad*2] [-height] [height] condition destroy 

;wall generating

program call 'boundary_generate.dat'

;ball generating

ball distribute porosity [poros] box [-rad] [rad] [-rad] [rad] [-height/2] [height/2] radius [b_rad] ...

                range cylinder end-1 (0,0,[-height/2*0.98]) end-2 (0,0,[height/2*0.98]) radius [rad*0.98]

;ball attribute generating

ball attribute density [Density*10000] damp 0.7

;contact model setting

contact cmat default type ball-facet model linear method deformability emod 1e8 kratio 1.5 property fric 0.2

contact cmat default type ball-ball model linear method deformability emod 1e8 kratio 1.5

contact cmat apply 

;balance model

model cycle 1000 calm 10

model mechanical timestep scale

model solve ratio-average 5e-5 max_cycles 5000

model mechanical timestep auto

;Return the contact force to zero 

contact property lin_force 0 0 0 rr_moment 0 0 0 lin_mode 1

ball attribute force-contact multiply 0 moment-contact multiply 0

model cycle 1

;save model

model save '1specimen'

2.预压

model restore '1specimen'

program call 'MonitorUtilities.p3fis'

program call 'ServoUtilities.p3fis'

[targetzz = 10e3]

structure node free velocity rotation range group 'middle'

structure shell apply [-targetzz] range group 'middle'

ball property 'kn' 0 'ks' 0

wall property 'kn' 0 'ks' 0

@_compute_dia

[wlz_ini=wlz]

[wlr_ini=wlr]

contact cmat default type ball-facet model linear method deformability emod 1e8 kratio 1.5

contact cmat default type ball-ball model rrlinear property fric [fric] rr_fric [rr_fric] method deformability emod 1e8 kratio 1.5

contact cmat apply

model calm

model cycle 1

wall servo activate on force-z [-targetzz*math.pi()*rad^2.0] ...

                       velocity-max 1 range set id 2

wall servo activate on force-z [targetzz*math.pi()*rad^2.0] ...

                       velocity-max 1 range set id 1

history interval 100

fish callback add @servo_walls -1.0

model calm

[stop_me_compaction = 0]

model solve fish-halt @stop_me_compaction

model save '2yuya'

program return

3.围压

model restore '2yuya'

[targetzz = 100e3]

structure shell apply [-targetzz] range group 'middle'

[stop_me_compaction = 0]

model solve fish-halt @stop_me_compaction

model save '3weiya'

program return

本案例全部计算代码如下，附件可直接导入PFC。