Ashish Khemka
Ansys Employee

 

Translated:

=========

 

Simulation of a prestressed concrete beam, deformation 10 mm smaller than real test

Hello,

I am simulating a test experiment with nonlinear boundary conditions. Microplane and a pretension with Inistate are used, but my deformations of the carrier are too small. In addition, my comparative strains and stresses in the stirrup reinforcement are too small or not really activated. I'm asking for help or solutions, so don't let my wearer look so stiff. It seems as if only the longitudinal reinforcement is active or influenced. The NL reinforcement IS defined via the technical data.

My APDL:

! Define the material properties !
/PREP7
 
! define item
ET,conc.,215
KEYO,conc,18,2 ! Activate additional degrees of freedom
 
! First step: define elastic properties!
 
E=33000 !E-modulus, Mpa concrete
nu=0.2 ! Poisson's ratio of concrete
 
! Second step: define the microplane model properties !
 
fc=45 ! Uniaxial compressive strength of the concrete class, Mpa !
fb=50 ! concrete class biaxial compressive strength, Mpa !
feet=3.5 ! Concrete class tensile strength, Mpa !
Rt=1 ! hardening
D=4e4 ! compressive strength constant !
sigma_cv = -31.67 ! compressive stress !
RC = 2 ! pressure ratio !
gamma_t = 0 ! Damage from train!
gamma_c = 5e-5 ! Damage from pressure!
beta_t = 4500 ! Coefficient for the development of stress damage !
beta_c = 3000 ! Coefficient for the development of pressure damage !
 
! Third step: define the non-local parameters c and m !
 
c = 1000 !
m = 2.5 !
 
! Fourth step: Choose element!
 
item = 215 !
 
 
! =============================================== === ==============
 
 
! Assign the elastic properties to !
 
MP,EX,Conc,E ! Assign Young's modulus !
MP,NUXY,conc,nu ! Assign Poisson's ratio !
 
! Map microplane properties for coupled damaged plasticity !
 
TB,MPLANE,conc,,,DPC
TBDATA,1,fc,fb,ft,Rt,D,sigma_cv
TBDATA,7,Rc,gamma_t,gamma_c,beta_t,beta_c
 
! Assign nonlocal properties to the microplane model!
 
TB,MPLANE,conc,,,NLOCAL
TBDATA,1,c,m
 
ALLESEL
esel,s,ename,,SOLID185
emodif,all,type,conc
allel
 
! Print out the result:
etliste, all
 
 
! item list!
 
!allsel
!etliste, all
FINISHED
! Solution!
/SOLUTION
outres, all, all