1! 2! CalculiX - A 3-dimensional finite element program 3! Copyright (C) 1998-2021 Guido Dhondt 4! 5! This program is free software; you can redistribute it and/or 6! modify it under the terms of the GNU General Public License as 7! published by the Free Software Foundation(version 2); 8! 9! 10! This program is distributed in the hope that it will be useful, 11! but WITHOUT ANY WARRANTY; without even the implied warranty of 12! MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13! GNU General Public License for more details. 14! 15! You should have received a copy of the GNU General Public License 16! along with this program; if not, write to the Free Software 17! Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 18! 19 subroutine creep(decra,deswa,statev,serd,ec,esw,p,qtild, 20 & temp,dtemp,predef,dpred,time,dtime,cmname,leximp,lend, 21 & coords,nstatv,noel,npt,layer,kspt,kstep,kinc) 22! 23! user creep routine 24! 25! INPUT (general): 26! 27! statev(1..nstatv) internal variables 28! serd not used 29! ec(1) equivalent creep at the start of the increment 30! ec(2) not used 31! esw(1..2) not used 32! p not used 33! temp temperature at the end of the increment 34! dtemp not used 35! predef not used 36! dpred not used 37! time(1) value of the step time at the end of the increment 38! time(2) value of the total time at the end of the increment 39! dtime time increment 40! cmname material name 41! leximp not used 42! lend if = 2: isotropic creep 43! if = 3: anisotropic creep 44! coords(1..3) coordinates of the current integration point 45! nstatv number of internal variables 46! noel element number 47! npt integration point number 48! layer not used 49! kspt not used 50! kstep not used 51! kinc not used 52! 53! INPUT only for elastic isotropic materials: 54! qtild von Mises stress 55! 56! INPUT only for elastic anisotropic materials: 57! decra(1) equivalent deviatoric creep strain increment 58! 59! 60! OUTPUT (general): 61! 62! decra(5) derivative of the equivalent deviatoric 63! creep strain increment w.r.t. the von Mises 64! stress 65! 66! OUTPUT only for elastic isotropic materials: 67! decra(1) equivalent deviatoric creep strain increment 68! 69! OUTPUT only for elastic anisotropic materials: 70! qtild von Mises stress 71! 72 implicit none 73! 74 character*80 cmname 75! 76 integer leximp,lend,nstatv,noel,npt,layer,kspt,kstep,kinc 77! 78 real*8 decra(5),deswa(5),statev(*),serd,ec(2),esw(2),p,qtild, 79 & temp,dtemp,predef(*),dpred(*),time(2),dtime,coords(*) 80! 81 qtild=(1.d10*decra(1)/dtime)**0.2d0 82 decra(5)=5.d-10*dtime*qtild**4 83! 84 return 85 end 86