HELICAL SPRINGS
FOLLOWING DIN EN 13906-1,2,3
Order : Dware
Project : HeliSpring
Subproject : Verification 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

Spring Specifications Symbol Unit Value
Outside diameter of spring De mm 60.00
Nominal diameter of wire d mm 7.000
Coil space unloaded spring a mm 0.140
Total number of coils nt -- 168.00
Body length unloaded LK0 mm 1200.0
Type spring end A ETA -- rad inside
Number of inactive coils A nnaA -- 0.00
Distance force action point LFA mm 20.0
Length of end lA mm 6.0
Inner bending radius of end rA mm 3.5
Type spring end B ETB -- rad inside
Number of inactive coils B nnaB -- 0.00
Distance of force action point LFB mm 20.0
Length of spring end lB mm 6.0
Inner bending radius of end rB mm 3.5
Hand of coils -- -- left
Coiling -- -- cold
Shot peening -- -- Yes
Spring Load Symbol Unit Value
Loading by -- -- tors revolut
Minor number wind up revolutions nrev1 rev 0.900
Major number wind up revolutions nrev2 rev 6.500
Number of loading cycles Ncy Mcy 0.010
Calculation of geometry Symbol Unit Value
Outside diameter of spring De mm 60.00
Mean diameter of coil D mm 53.00
Inside diameter of spring Di mm 46.00
Spring index w -- 7.57
Number of active coils n -- 168.00
Developed length of active coils l mm 27998
Spring rate RMRv N.m/rev 5.449
Coil pitch when unloaded m0 mm 7.140
Coil space unloaded spring a mm 0.140
Max permissible space between coil amax mm 12.77
Force in action point leg A FA N 1771.100
Force in action point leg B FB N 1771.100
Free body length LK0 mm 1206.5
Spring diagram Symbol Unit Value
Minor torsional moment M1 N m 4.905
Minor torsion angle nrev1 rev 0.900
Major torsional moment M2 N m 35.422
Major torsion angle nrev2 rev 6.500
Max permissible torsional moment Mn N m 36.380
Max permissible torsion angle nrevn rev 6.676
Strength calculation Symbol Unit Value
Stress correction factor q -- 1.120
Corrected minor bending stress σbq1 N/mm˛ 163
Corrected major bending stress σbq2 N/mm˛ 1178
Permissible static bending stress SbP N/mm˛ 1210
Safety factor major bend stress SF -- 1.03
Strength domain -- -- static
Permissible endurance stress σbeN N/mm˛ 1210
Permissible upper bending stress σbqO N/mm˛ 1210
Safety factor upper bending stress SFO -- 1.03
Corrected lower bending stress σbqU N/mm˛ 163
Stroke bending stress σbqh N/mm˛ 1015
Permissible stroke bending stress σbqH N/mm˛ 1047
Safety fact stroke bending stress SFH -- 1.03
Length - weight of wire Symbol Unit Value
Total length of developed wire lw mm 28025
Mass of spring mw g 8467
Spring work Symbol Unit Value
Minor spring work W1 J 13.869
Major spring work W2 J 723.330
Work exchange DW J 709.461
Frequency analysis Symbol Unit Value
Natural revolv-frequency of coils fa Hz 6.01