The spring index is expressed as___________________?
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Answer: A. ratio of coil diameter to wire diameter
Explanation
The spring index is defined mathematically as the ratio of mean coil diameter to wire diameter. This dimensionless geometric parameter helps evaluate the manufacturability of helical coil springs. Dividing the coil diameter by the wire thickness yields the exact spring index value. Helical springs are mechanical devices designed to store energy and absorb shock loads. Mean coil diameter is measured from the center of the wire on one side to the other. Wire diameter dictates the cross sectional strength and stiffness characteristics of the spring.
Spring index values between four and twelve are generally preferred for easy manufacturing. A very low spring index makes coiling difficult and introduces high residual curvature stresses. Engineers use the spring index to calculate correct Wahl stress correction factors accurately. Load per unit deflection defines spring rate rather than the geometric spring index. Energy storage capability depends on material volume, displacement, and spring stiffness properties. Spring index is a precise engineering ratio rather than a vague qualitative quality indicator.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
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