(defun Pf_bend_allowance_din (&key sheet_thickness bend_angle bend_radius
                                   sheet_material tool_id
                              &allow-other-keys )
  ;____________________________________________________________________________
  ;
  ;  Diese Funktion berechnet den Einzugswert einer Biegung unter benutzung
  ;  der DIN-Formel zur Berechnung des k-Faktors.
  ;  Der K-Faktor beschreibt die Lage der neutralen Faser zwischen Innen- und
  ;  AuÞenseite der Biegung.
  ;  Aus dem K-Faktor, der Materialdicke, dem Winkel der Biegung und dem
  ;  Biegeradius wird in einer Unterfunktion der Einzugswert berechnet und 
  ;  zurÏckgegeben.
  ;        
  ;                 DIN    ANSI         Achtung:
  ;                                     Der K-Faktor ist in der DIN-Formel
  ;         _______  2      1           anders definiert, als in der ANSI-
  ;       /                             Formel.
  ;      /       ..  1      0,5         Der DIN-Wert entspricht dem doppelten
  ;     /     .                         ANSI-Wert (siehe Beispiel).
  ;    /    .    __  0      0
  ;   /    .    /
  ;   |    .    |
  ; 
  ;
  ; INPUT
  ; =====
  ; sheet_thickness   Material thickness [mm]                           
  ; bend_angle        [deg] bend angle of bend  (0 = no bend )          
  ; bend_radius       [mm] bend radius of bend  (0 = no bend )           
  ; sheet_material    Material property list :                           
  ;                     syntax:
  ;                      (:shopname <shopname> :tabname <sheet mat. table>
  ;                       :rowkey <material key property list>)
  ;                     syntax e.g.
  ;                      (:SHOPNAME "demoshop" :TABNAME "sheet_metals" 
  ;                       :ROWKEY (:MATERIAL "UST 1203" :THICK 1.25))
  ;
  ;
  ; RETURN
  ; ======
  ; property list ( :allowance allowance-value         ; if not given the
  ;                                                    ; system uses a 
  ;                                                    ; fallback strategy
  ;                 :warning-headline message-string   ; optional
  ;                 :error-type violation-type         ; optional
  ;                 :error-message message_string )    ; optional
  ;___________________________________________________________________________

  
  (declare (ignore sheet_material)) ; to keep compiler quite when compiling

;  (display  sheet_material)
;  (display (nth 5 sheet_material))

  (setf pf_material_list (nth 5 sheet_material))
  (setf pf_material (nth 1 pf_material_list))
;  (setf pf_mat_list (sd-string-split pf_material " "))
;;  (display pf_material)


  (let* (R_t
         R_t_Kehrwert
         Offset
         Min-K-Factor
         Max-K-Factor
;;         K_factor_echt
         K_factor
         Materialtyp
         return_values
        
         (shopname           (getf sheet_material :shopname))
         (tool-rowkey        (or (getf tool_id :rowkey)
                                ; if used as fallback formula (no tool_id)
                                  (list :RADIUS bend_radius)))
         (allowance-table    (if tool_id
                                (sha-get-db-entry tool_id :ALLOWANCE_TABLE)
                                ; if used as fallback formula (no tool_id)
                                (sha-get-shop-entry
                                     :shopname shopname
                                     :column   :ALLOWANCE_TABLE)))
         (material-rowkey    (getf sheet_material :rowkey))
         (material-keys      (sha-separate-plist material-rowkey))
         (tool-keys          (remove ':angle (sha-separate-plist 
                                                     tool-rowkey)))
                                                      
        )

    (setf R_t (/ bend_radius sheet_thickness))
    (setf R_t_Kehrwert (/ sheet_thickness bend_radius))
    ; Calculate k-factor according DIN 
    
;*****************************************************************************
;**  Allowance-Formel-Anpassung fÏr Buntmet./Stahl:
;*****************************************************************************   
    (if (sd-string= pf_material "Buntmetall")
      (progn
        (setf Offset 0.65)      
        (setf Min-K-Factor 0.66)
        (setf Max-K-Factor 1)
        (setf K_factor_echt (+ Offset (/ (log R_t 10) 2)))
      )
    ) 
    
    
;*****************************************************************************
;**  Allowance-Formel-Anpassung fÏr Buntmet./Stahl:
;*****************************************************************************   
    (if (sd-string= pf_material "Stahl")
      (progn
        (setf Offset 0.65)      
        (setf Min-K-Factor 0.66)
        (setf Max-K-Factor 1)
        (setf K_factor_echt (+ Offset (/ (log R_t 10) 2)))
      )
    ) 
    
;*****************************************************************************
;**  Allowance-Formel-Anpassung fÏr K-Materialien:
;*****************************************************************************   
    (if (sd-string= pf_material "K-Materialien")
      (progn
        (setf Offset 0.65)      
        (setf Min-K-Factor 0.66)
        (setf Max-K-Factor 1)
        (setf K_factor_echt (+ Offset (/ (log R_t 10) 2)))
      )
    )   
    
;*****************************************************************************
;**  Allowance-Formel-Anpassung fÏr Nirosta:
;***************************************************************************** 
    (if (sd-string= pf_material "Nirosta")
      (progn
        (setf Offset 0.65)      
        (setf Min-K-Factor 0.66)
        (setf Max-K-Factor 1)
        (setf K_factor_echt (+ Offset (/ (log R_t 10) 2)))
        ;;(setf K_factor_echt (+ Offset (/ (*(log R_t 10) (+ (/ R_t_Kehrwert 2.7) 0.5)) 2)))
      )
    )   
    
   
;;    (display (fix_mesg "Offset : {1}" (sd-num-to-string Offset 2) ))
;;    (display (fix_mesg "Min-K-Factor : {1}" (sd-num-to-string Min-K-Factor 2) ))
;;    (display (fix_mesg "Max-K-Factor : {1}" (sd-num-to-string Max-K-Factor 2) ))
    
      (if (< R_t  0.65 )
         (if (and *Sh_global_dfm_checks* *Sh_local_dfm_checks*)
            (progn
               (setf return_values 
                  (list :warning-headline "WARNUNG: VerstoÞ gegen Fertigungsregel (DFM)."
                        :error-type :DFM_rule_violation
                        :error-message 
                        "VerhÌltnis Radius/Dicke sollte nicht kleiner als 0.65 sein."
                  )
               )
            )             
         )   
      )
  
      
                   
      (if (> K_factor_echt Max-K-Factor)     ;maximalen K-Faktor auf Max-K-Factor begrenzen 
         (progn        
            (setf K_factor Max-K-Factor)
            (progn
               (setf return_values 
                  (list :warning-headline "Info"
                      :error-type :DFM_rule_violation
                      :error-message 
                      (fix_mesg "DIN-K_factor ist grÎÞer als {1}, wird auf {1} gesetzt" (sd-num-to-string Max-K-Factor 2))
                  )   
               )
            )  
         )
      )     
      
          
      (if (< K_factor_echt Min-K-Factor)   ;minimalen K-Faktor auf Min-K-Factor begrenzen  
         (progn       
            (setf K_factor Min-K-Factor)
            (progn
               (setf return_values 
                  (list :warning-headline "Info"
                     :error-type :DFM_rule_violation
                     :error-message 
                     (fix_mesg "DIN-K_factor ist kleiner als {1}, wird auf {1} gesetzt" (sd-num-to-string Min-K-Factor 2))
                  )
               )
            )             
         )
      )
      
      (if (and(>= K_factor_echt Min-K-Factor)(<= K_factor_echt Max-K-Factor))
         (setf K_factor K_factor_echt)       
      )
      
     (progn
       
          (nconc return_values
                (list
                  :error-message 
                  (fix_mesg "Offset : {1}" (sd-num-to-string Offset 2) )
                  :error-message
                  (fix_mesg "Min-K-Factor : {1}" (sd-num-to-string Min-K-Factor 2) )
                  :error-message
                  (fix_mesg "Max-K-Factor : {1}" (sd-num-to-string Max-K-Factor 2) ) 
                )                 
          )
      
    )      
    
;;      (display " ")
;;      (display (fix_mesg "ermittelter K-Faktor (DIN) : {1}" (sd-num-to-string K_factor 4) ))
;;      (display (fix_mesg "ermittelter K-Faktor (ANSI): {1}" (sd-num-to-string (/ K_factor 2) 4) ))
;;      (display " ")
;;      (display " ")
  
;*********************************************************************  
     
 
  ; Calculate bend allowance and set global return value  
  ; Pass open angle between bent lips instead bend angle 

  (append return_values (list :allowance 
    (Sh_calculate_bend_allowance_DIN sheet_thickness bend_radius 
                                     (- 180 bend_angle) K_factor)))
    
;;  (setf test
;;  (append return_values (list :allowance 
;;    (Sh_calculate_bend_allowance_DIN sheet_thickness bend_radius 
;;                                     (- 180 bend_angle) K_factor) 
;;                                   :K_factor_echt K_factor_echt))
;;  )                                     
;;  (display test)                                   
  );end let
;; (display K_factor_echt)
)