HELICAL SPRINGS
FOLLOWING DIN EN 13906-1,2,3
Order : Dware
Project : HeliSpring
Subproject : Dimensioning Torsion Spring
Project item : Spring for Sectional Car Port
Spring ID : 60x1200
Calculated by : André Dewispelaere
Organization : Dware
Date : 26/07/2021 




   Spring wire grade




 Nr, Cl, Spring Wire Grade       ,      E,     G,  rho,  Rm1, Rco




230, FD, EN 10270-2 FDSiCr       , 206000, 79500, 7.85, 2000, 320
Calculated wire properties Symbol Unit Value
Wire diameter d mm 7.000
Minimum value tensile strength Rm N/mm˛ 1730
Modulus of rigidity G N/mm˛ 79500
Modulus of Elasticity E N/mm˛ 206000

Design Specifications Symbol Unit Value
Minor torsional moment M1 N m 8.000
Major torsional moment M2 N m 32.200
Major number wind up revolutions nrev2 rev 7.000
Number of loading cycles Ncy Mcy 0.010
Inside diameter not less than Di mm 46.00
Approximate coil space unloaded a mm 0.00
Forming -- -- cold
Hand of coiling -- -- right
Shot peening -- -- Yes
Calculation of geometry Symbol Unit Value
Calculated wire diameter dc mm 6.56
Selected wire diameter d mm 7.000
Minimum diameter of wire dmin mm 6.350
Choosen mean diameter of coil D mm 53.00
Spring index w -- 7.57
Outside diameter of spring De mm 60.00
Inside diameter of spring Di mm 46.00
Choosen coil pitch unloaded m0 mm 7.100
Resulting coil space unloaded a mm 0.100
Max permiss space between coils amax mm 12.77
Choosen number of active coils n -- 168.00
Body length when unloaded LW mm 1199.8
Length of evolved active coils l mm 27998
Angular spring rate RMRv N.m/rev 5.450
Type of spring end A ETA -- rad inside
Number of inactive coils A nnaA -- 0.00
Distance of force action point LFA mm 16.0
Length of end A lA mm 7.0
Inner bending radius end A rA mm 7.0
Major force acting on spring end FA N 2012.500
Type spring end B ETB -- rad inside
Number of inactive coils B nnaB -- 0.00
Distance force action point LFB mm 16.0
Length of end B lB mm 7.0
Inner bending radius of end B rB mm 7.0
Major force acting on spring end FB N 2012.500
Total number of coils nt -- 168.00
Total free state body length L0 mm 1199.8
Calculation spring diagram Symbol Unit Value
Minor torsional moment M1 N m 8.000
Minor torsion angle nrev1 rev 1.468
Major torsional moment M2 N m 32.200
Major torsion angle nrev2 rev 5.909
Max permissible torsional moment Mn N m 36.380
Max permissible torsion angle nrevn rev 6.680
Strength calculation Symbol Unit Value
Stress correction factor q -- 1.120
Minor corrected bending stress σbq1 N/mm˛ 266
Major corrected bending stress σbq2 N/mm˛ 1071
Permissible static bending stress σbP N/mm˛ 1210
Safety factor stat bending stress SF -- 1.27
Strength domain -- -- static
Permissible endurance stress σeN N/mm˛ 1210
Permissible upper bending stress σbqO N/mm˛ 1210
Safety factor on upper bend stress SFO -- 1.13
Torsion stroke bending stress σbqh N/mm˛ 805
Permissible stroke bending stress σbH N/mm˛ 944
Safety factor stroke stress SFH -- 1.17
Length of wire and mass Symbol Unit Value
Evolved length of wire lw mm 28031
Spring mass mw g 8468
Spring work Symbol Unit Value
Minor spring work W1 J 36.895
Major spring work W2 J 597.719
Work exchange DW J 560.824