# Terminology and symbols

**Excerpt of the most important variables for an anchor design with DesignFiX.**

These terms we use in our DesignFiX documentation.

1 | a3 | Increase of the lever arm of a shear load due to spalling of the concrete surface during drilling |

4 | A°c,N | Base area of the idealized failure body of a single anchor not influenced by adjacent anchors or component edges for conical concrete break-out and splitting under tension load |

5 | A c,N | Base area of the idealized failure body of a fastening for conical concrete break-out and splitting under tension load |

6 | A° c,V | Base area of the idealized failure body of a single anchor not influenced by adjacent anchors or further component edges for concrete edge failure under shear load |

7 | A c,V | Base area of the idealized failure body of a fastening for concrete edge failure under shear load |

8 | A° p,N | Base area of the idealized failure body of a single anchor not influenced by adjacent anchors or component edges for combined pull-out and concrete failure (chemical anchors) under tension load |

9 | A p,N | Base area of the idealized failure body of a fastening for combined pull-out and concrete failure (chemical anchors) under tension load |

10 | c, c 1 , c 2 , c 2,1 , c 2,2 | Edge distances |

11 | c cr,N | Characteristic edge distance for conical concrete break-out under tension load |

12 | c cr,Np | Characteristic edge distance for combined pull-out and concrete failure (chemical anchors) under tension load |

13 | c cr,sp | Characteristic edge distance for splitting of the component under tension load |

14 | c cr,V | Characteristic edge distance for concrete edge failure under shear load |

15 | c min | Minimum permissible edge distance |

16 | d | Diameter of anchor bolt or thread diameter; anchors with internal thread: outer diameter of the bolt |

17 | d f | Diameter of the hole in the base plate or fixture |

18 | d nom | Outside diameter of the anchor |

19 | e 1 | Distance between the shear load and the surface of the concrete for shear load with lever arm |

20 | E c | Modulus of elasticity of concrete |

21 | E d | Value of design action |

22 | e N e N,1 , e N,2 | Eccentricity of the resultant of the tension-loaded anchors with respect to the centre of gravity of these anchors |

23 | e V | Eccentricity of the resultant of the shear-loaded anchors close to an edge with respect to the centre of gravity of these anchors for concrete edge failure |

24 | f ck,cube | Concrete compressive strength for cubes with a side length of 150 mm |

25 | h | Component thickness |

26 | h ef | Embedment depth of an anchor |

27 | h‘ ef | Modified embedment depth of an anchor for the special case „three or four edges“ under tension load |

28 | h min | Minimum permissible component thickness |

29 | I p | Radial moment of inertia |

30 | I | Lever arm of a shear load |

31 | l f | Effective anchor length |

32 | M Ed | Design value of the acting bending moment |

33 | M Ed,x | Design value of the acting bending moment Mx |

34 | M Ed,y | Design value of the acting bending moment My |

35 | n | Number of anchors in a group |

36 | N Ed | Design value of the acting tension load |

37 | N hEd | Design value of the tension load acting on the highest loaded anchor of a group |

38 | N gEd | Design value of the acting tension load of a group |

39 | N Rd,s | Design value of the characteristic resistance for steel failure under tension load |

40 | N Rd,p | Design value of the characteristic resistance for pull-out/pull-through (mechanical anchors) under tension load |

41 | N Rd,c | Design value of the characteristic resistance for conical concrete break-out under tension load |

40 | N Rd,sp | Design value of the characteristic resistance for splitting under tension load |

42 | N° Rk,c | Characteristic resistance of a single anchor not influenced by adjacent anchors and component edges for conical concrete break-out under tension load |

43 | N Rk,c | Characteristic resistance of a fastening for conical concrete break-out under tension load |

44 | N° Rk,p | Characteristic resistance of a single anchor not influenced by adjacent anchors and component edges for combined pull-out and concrete failure (chemical anchors) under tension load |

45 | N Rk,p | Characteristic resistance of a fastening for pull-out/pull-through (mechanical anchors) and combined pull-out and concrete failure (chemical anchors) under tension load |

46 | N Rk,s | Characteristic resistance for steel failure under tension load |

47 | N Rk,sp | Characteristic resistance for splitting under tension load |

48 | R d | Value of the design resistance |

49 | R k | Characteristic resistance |

50 | s, s1, s2, s1,1, s1,2, s2,1, s2,2 | Axial spacing of anchors |

51 | s cr,N | Characteristic axial spacing for conical concrete break-out under tension load |

52 | s cr,Np | Characteristic axial spacing for combined pull-out and concrete failure (chemical anchors) under tension load |

53 | s cr,sp | Characteristic axial spacing for splitting under tension load |

54 | s cr,V | Characteristic axial spacing for concrete edge failure under shear load |

55 | s min | Minimum permissible axial spacing |

56 | S | |

57 | V Ed | Design value of the acting shear load V |

58 | V hEd | Design value of the shear load acting on the highest loaded anchor of a group |

59 | V gEd | Design value of the shear load acting on a group |

60 | V Ed,h | Horizontal component of the acting shear load |

61 | V Ed,v | Vertical component of the acting shear load |

62 | V Rd,c | Design value of the resistance for concrete edge failure under shear load |

63 | V Rd,cp | Design value of the resistance for pry-out failure under shear load |

64 | V Rd,s | Design value of the resistance for steel failure under shear load |

65 | V° Rk,c | Characteristic resistance of a single anchor not influenced by adjacent anchors, further component edges and the component thickness for concrete edge failure under shear load |

66 | V Rk,c | Characteristic resistance of a fastening for concrete edge failure under shear load |

67 | V Rk,cp | Characteristic resistance of a fastening for pry-out failure under shear load |

68 | V Rk,s | Characteristic resistance for steel failure under shear load |

69 | α gap | |

70 | α M | Restraint of the anchor at the side of the base plate or fixture |

71 | α seis | |

72 | α V | Angle between the acting shear load and a line perpendicular to the edge |

73 | β N | Ratio between the design action and the design resistance for tension load |

74 | β V | Ratio between the design action and the design resistance for shear load |

75 | γ M | Partial safety factor for the material |

76 | γ Mc | Partial safety factor for conical concrete break-out |

77 | γ Mp | Partial safety factor for pull-out/pull-through (mechanical anchors) and combined pull-out and concrete failure (chemical anchors) |

78 | γ Ms | Partial safety factor for steel failure |

79 | γ Msp | Partial safety factor for splitting failure |

80 | τ Rk | Characteristic bond strength of a chemical anchor |

81 | τ Rk,ucr | Characteristic bond strength of a chemical anchor in non-cracked concrete |

82 | Ψ α ,V | Factor to consider the effect of the load direction for concrete edge failure under shear load |

83 | Ψ ec,N | Factor to consider the effect of the load eccentricity for conical concrete break-out and splitting under tension load |

84 | Ψ ec,Np | Factor to consider the effect of the load eccentricity for combined pull-out and concrete failure (chemical anchors) under tension load |

85 | Ψ ec,V | Factor to consider the effect of the load eccentricity for concrete edge failure under shear load |

86 | Ψ g,Np | Factor to consider the effect of small axial spacing for combined pull-out and concrete failure (chemical anchors) under tension load |

87 | Ψ h,N | Factor to consider the effect of the component thickness for splitting failure under tension load |

88 | Ψ h,V | Factor to consider the effect of the component thickness for concrete edge failure under shear load |

89 | Ψ re,N | Factor to consider the effect of a dense surface reinforcement for conical concrete break-out and splitting failure under tension load |

90 | Ψ re,Np | Factor to consider the effect of a dense surface reinforcement for combined pull-out and concrete failure (chemical anchors) under tension load |

91 | Ψ re,V | Factor to consider the effect of the position of the anchor and of an edge reinforcement for concrete edge failure under shear load |

92 | Ψ s,N | Factor to consider the effect of an edge on the stress distribution in the concrete for conical concrete break-out and splitting failure under tension load |

93 | Ψ s,Np | Factor to consider the effect of an edge on the stress distribution in the concrete for combined pull-out and concrete failure (chemical anchors) under tension load |

94 | Ψ s,V | Factor to consider the effect of further edges on the stress distribution in the concrete for concrete edge failure under shear load |