A helical compression spring, made of circular wire, is subjected to an axial forcewhich varies from 4 kN to 5.5 Kn. Over this range of force, the deflection of the springshould be approximately 6 mm. The spring index can be taken as 4. The spring has squareand ground ends. The spring is made of patented and cold-drawn steel wire with ultimatetensile strength of 1180 N/mm and modulus of rigidity of 82140 N/mm2. The permissibleshear stress for the spring wire should be taken as 40% of the ultimate tensile strength
Design the spring and calculate
(i) wire diameter;
(ii) mean coil diameter;
(iii) number of active coils;
(iv) total number of coils;
(v) solid length of the spring; (vi) free length of the spring:
(vii) required spring rate; and
(viii) actual spring rate