C GFLEX1    SOURCE    CHAT      05/01/13    00:18:02     5004           
      SUBROUTINE GFLEX1(AB,DLL,RF,CTC,DELTAT,LANBN)                             
      IMPLICIT INTEGER(I-N)
      IMPLICIT REAL*8(A-H,O-Z)                                                  
C                                                                               
C  =====================================================================        
C    SOUS-PROGRAMME FORTRAN APPELE PAR GREEN1 POUR CALCULER LES FCTS DE         
C    GREEN EN FLEXION                                                           
C    CREATION    : 21/09/87                                                     
C    PROGRAMMEUR : GUILBAUD                                                     
C  =====================================================================        
-INC CCOPTIO                                                                    
-INC CCREEL                                                                     
      DIMENSION AB(10,*)                                                        
      WRITE(IOIMP,*) ' DEBUT DE GFLEX1 '                                        
      PIS4=XPI*0.25D0                                                           
      RPI=1.D0/SQRT(XPI)                                                        
      XP=1.D0                                                                   
      XG=20.D0                                                                  
      XTG=200.D0                                                                
C                                                                               
C--------BOUCLE SUR LES PAS DE TEMPS -------------------------                  
C                                                                               
      GP4=0.D0                                                                  
      GP3=0.D0                                                                  
      GP2=0.D0                                                                  
      GP1=0.D0                                                                  
      GP0=0.D0                                                                  
      GPL0=0.D0                                                                 
      G4P=0.D0                                                                  
      G3P=0.D0                                                                  
      G2P=0.D0                                                                  
      G1P=0.D0                                                                  
      G0P=0.D0                                                                  
      DTM=DLL*DLL/(3.D0*CTC*RF*XPI)                                             
      LANBN1=LANBN+1                                                            
      DO 40 L=1,LANBN1                                                          
      T=L*DELTAT                                                                
C                                                                               
C--------BOUCLE SUR LES EXTREMITES----------------------------                  
C                                                                               
      DO 20 NE=1,2                                                              
      DL=0.D0                                                                   
      IF(NE.EQ.2) DL=DLL                                                        
      DKSI=DL/RF                                                                
      CSRF=CTC/RF                                                               
      TETA=CSRF*T                                                               
      RTETA=SQRT(TETA)                                                          
      STK=0.5D0/RTETA                                                           
      U2=DKSI*DKSI/(4.D0*TETA)                                                  
      SDK=RPI*SIN(U2-PIS4)                                                      
      CDK=RPI*COS(U2-PIS4)                                                      
      IF(NE.EQ.1) THEN                                                          
C                                                                               
C  PREMIERE EXTREMITE                                                           
C                                                                               
        G4=-STK*CDK                                                             
        G3=0.5D0                                                                
        G2=RTETA*SDK                                                            
        G1=0.D0                                                                 
        G0=(2.D0/3.D0)*RTETA*TETA*CDK                                           
        AB4=G4-GP4                                                              
        GP4=G4                                                                  
        AB3=G3-GP3                                                              
        GP3=G3                                                                  
        AB2=G2-GP2                                                              
        GP2=G2                                                                  
        AB1=G1-GP1                                                              
        GP1=G1                                                                  
        AB0=G0-GP0                                                              
        GP0=G0                                                                  
        AB(1,L)=AB0                                                             
        AB(2,L)=AB1                                                             
        AB(3,L)=AB2                                                             
        AB(4,L)=AB3                                                             
        AB(5,L)=AB4                                                             
      ELSE                                                                      
C                                                                               
C  SECONDE EXTREMITE                                                            
C                                                                               
        IF(U2.GT.XTG) THEN                                                      
          TK=2.D0*TETA/DKSI                                                     
          TK1=STK*TK                                                            
          TK2=TK1*TK                                                            
          TK3=TK2*TK                                                            
          TK4=TK3*TK                                                            
          TK5=TK4*TK                                                            
          TK6=TK5*TK                                                            
          G3=-TK1*SDK                                                           
          G2=TK2*CDK                                                            
          G1=TK3*SDK                                                            
          G0=-TK4*CDK                                                           
          GG3=-TK3*CDK                                                          
          GG2=-TK4*SDK                                                          
          GG1= TK5*CDK                                                          
        ELSE                                                                    
          IF(T.EQ.DELTAT) THEN                                                  
            U2P=XG+1.D0                                                         
          ELSE                                                                  
            U2P=DKSI*DKSI/(4.D0*CSRF*(T-DELTAT))                                
          ENDIF                                                                 
          IF(U2.GT.XP.AND.U2P.LT.XG) THEN                                       
            CALL INTFR2(DCC,DSS,U2P,U2)                                         
            SS=SS-DSS                                                           
            CC=CC-DCC                                                           
          ELSE                                                                  
            CALL INTFRE(CC,SS,U2)                                               
          ENDIF                                                                 
          SC=SS-CC                                                              
          SC1=1.D0-SS-CC                                                        
          U=SQRT(U2)                                                            
          U3=U*U2                                                               
          U4=U*U3                                                               
          GG4=-RTETA*(U*SC+CDK)                                                 
          G3=0.5D0*SC1                                                          
          G2=RTETA*(SDK+U*SC1)                                                  
          G1=RTETA*(0.5D0*RTETA*SC+U*G2)                                        
          G0=(2.D0/3.D0)*RTETA*(-RTETA*GG4+U*G1)                                
          GG3=TETA*(0.5D0*SC1-U*CDK-U2*SC)                                      
          GG2=(2.D0/3.D0)*TETA*RTETA*(SDK+1.5D0*U*SC1-U2*CDK-U3*SC)             
          GG1=TETA*RTETA*(1.5D0*SC+U*SDK+2.D0*(U3*CDK+U4*SC))/6.D0              
          GG1=RTETA*(GG1+U*GG2)                                                 
        ENDIF                                                                   
        IF(DELTAT.LE.DTM) THEN                                                  
          AB0=G0-GPL0                                                           
          GPL0=G0                                                               
          DELT=CSRF*DELTAT                                                      
          DELT2=DELT*DELT                                                       
          AB(6,L)=AB0                                                           
          AB(7,L)=GG1/DELT                                                      
          AB(8,L)=GG2/DELT                                                      
          AB(9,L)=GG3/DELT                                                      
          AB(10,L)=-AB0/DELT2                                                   
        ELSE                                                                    
          G4=-STK*CDK                                                           
          AB(10,L)=G4-G4P                                                       
          G4P=G4                                                                
          AB(9,L)=G3-G3P                                                        
          G3P=G3                                                                
          AB(8,L)=G2-G2P                                                        
          G2P=G2                                                                
          AB(7,L)=G1-G1P                                                        
          G1P=G1                                                                
          AB(6,L)=G0-G0P                                                        
          G0P=G0                                                                
        ENDIF                                                                   
      ENDIF                                                                     
   20 CONTINUE                                                                  
   40 CONTINUE                                                                  
C                                                                               
      IF(DELTAT.GT.DTM) RETURN                                                  
      DO 70 I=7,10                                                              
      GP=AB(I,2)-2.D0*AB(I,1)                                                   
      DO 50 L=2,LANBN                                                           
      GA=AB(I,L+1)-2.D0*AB(I,L)+AB(I,L-1)                                       
      AB(I,L-1)=GP                                                              
      GP=GA                                                                     
   50 CONTINUE                                                                  
      AB(I,LANBN)=GP                                                            
      GP=0.D0                                                                   
      DO 60 L=2,LANBN                                                           
      GA=0.5D0*(AB(I,L-1)+AB(I,L))                                              
      AB(I,L-1)=GP                                                              
      GP=GA                                                                     
   60 CONTINUE                                                                  
      AB(I,LANBN)=GP                                                            
   70 CONTINUE                                                                  
C                                                                               
      WRITE(IOIMP,*)' FIN DE GFLEX1 '                                           
      RETURN                                                                    
      END