弹簧常数计算器 — 公式
## Helical Spring Constant
The stiffness of a helical compression or extension spring depends on material properties, wire size, and coil geometry.
### Formula
**k = G d^4 / (8 D^3 Na)**
where G is the shear modulus, d is wire diameter, D is mean coil diameter, and Na is the number of active coils. The spring index C = D/d should be between 4 and 12 for practical manufacturability.
The stiffness of a helical compression or extension spring depends on material properties, wire size, and coil geometry.
### Formula
**k = G d^4 / (8 D^3 Na)**
where G is the shear modulus, d is wire diameter, D is mean coil diameter, and Na is the number of active coils. The spring index C = D/d should be between 4 and 12 for practical manufacturability.
计算示例
A steel spring with 3 mm wire, 25 mm mean coil diameter, 10 active coils, G = 79.3 GPa.
- G = 79,300 MPa (= N/mm^2)
- d^4 = 3^4 = 81
- D^3 = 25^3 = 15,625
- k = 79,300 x 81 / (8 x 15,625 x 10)
- k = 6,423,300 / 1,250,000 = 5.139 N/mm
- Spring index C = 25/3 = 8.33 (good, within 4-12 range)