在Itasca专有技术交流群(289141433)中,Itasca官方的老师对FLAC3D中的strain increment与strain rate的关系进行了说明,现对该说法进行验证。
2.代码
model new
model largestrain off
zone create brick size 1 1 1
zone cmodel assign elastic
zone property young 1e8 poisson 0.35 density 1800
zone face skin
zone face apply velocity-normal 0 range group 'south' or 'north'
zone face apply velocity-normal 0 range group 'east' or 'west'
zone face apply velocity-normal 0 range group 'bottom'
history interval 1
zone history name 'xxInc' strain-increment quantity xx position 1 1 1 method constant
zone history name 'xxRate' strain-rate quantity xx position 1 1 1 method constant
zone history name 'yyInc' strain-increment quantity yy position 1 1 1 method constant
zone history name 'yyRate' strain-rate quantity yy position 1 1 1 method constant
zone history name 'zzInc' strain-increment quantity zz position 1 1 1 method constant
zone history name 'zzRate' strain-rate quantity zz position 1 1 1 method constant
model gravity 9.81
model solve
history export 'xxInc' table '1'
history export 'xxRate' table '2'
history export 'yyInc' table '3'
history export 'yyRate' table '4'
history export 'zzInc' table '5'
history export 'zzRate' table '6'
fish def _dataTrans
loop i(1,72)
j = i - 1
table.x(7,i) = i
table.x(8,i) = i
table.x(9,i) = i
if i = 1
table.y(7,i) = table.y(1,i)
table.y(8,i) = table.y(3,i)
table.y(9,i) = table.y(5,i)
endif
if i > 1
table.y(7,i) = table.y(1,i) - table.y(1,j) ;xx rate
table.y(8,i) = table.y(3,i) - table.y(3,j) ;yy rate
table.y(9,i) = table.y(5,i) - table.y(5,j) ;zz rate
endif
endloop
end
@_dataTrans
图3-1 strain-rate-xx
图3-3 strain-rate-zz
由上图可知,虽然从视觉上看x方向与y方向的strain rate监测值与计算值曲线相差较大,但数值的量级为10的负21次方,可认为strain rate监测值与计算值一致;z方向的strain rate监测值与计算值曲线完美吻合。综上,可以认为本次验证基本成功。
strain increment的验证可参考下文:
验证strain increment即为单元应变
呱太Gekota,公 众号:FLAC3D小技巧小应变模式下的应变增量验证