PFC模拟单轴压缩代码

以下是PFC2D模拟单轴压缩的示例代码，其中假设已经定义了单轴压缩试验的模型和参数：

; Initialize PFC2D
model new
model random 1000
model large-strain on
model title "Uniaxial Compression Test"

; Define material properties
mat new
mat set model linear-elastic
mat set E 100e3
mat set density 2.7e3

; Define geometry
grid new
grid size 10 10
grid shape block 0 0 0 1 1 1
grid shape copy move 0 0 1

; Define boundary conditions
fix z 0
fix x range pos 0 1
fix y range pos 0 1

; Define contact properties
cont new
cont set model linear-linear
cont set stiffness 1e6
cont set cohesion 1e3
cont set friction 0.5

; Define loading conditions
hist new
hist set time-total 1
hist set time-step 1e-3
hist set displacement 0
hist set displacement-rate -1

; Run simulation
model solve

这段代码通过定义材料属性、几何形状、边界条件、接触特性和加载条件等，模拟了单轴压缩试验的全过程。其中`hist set displacement-rate -1`表示在时间上的负载速率为1，即每个时间步长位移减少1个单位。你可以根据自己的需要对代码进行修改和优化。