Determine number of coils and length of the spring:

A close coiled helical spring ought to extend by 120 mm under an axial force of 1200 N. If mean coil radius is equal to 40 mm and maximum shear stress is 300 MPa, determine the wire diameter, number of coils and length of the spring. Take G = 80 GPa.

Solution

Δ = 120 mm, W = 1200 N, R = 40 mm, τ_max  = 300 MPa ,

G = 80 GPa = 80 × 103 N/mm², d = ?, n = ?, l = ?

Using Eq. (3) for maximum shearing stress

τ           = 16W R  / π d³

or         300 = 16 × 1200 × R / π d ³

∴          R/ d ³  = 0.049  or R = 0.049 d ³ ----------- (1)

40/0.049       or d = 9.35 mm          --------- (2)

From Eq. (7)

Δ= 64 W R³ n / Gd ⁴

∴          120 =6 4× 1200 × R³ n/80 × 10³ × d ⁴

or R³ n/ d ⁴ = 125

Using values of R and d,

40³ × n / 9.354 = 125

∴          n = 14.9 ; 15

l = 2 π R n

= 2 π (40) (15)

= 3770 mm

Posted Date: 1/21/2013 1:11:56 AM | Location : United States

Ask an Expert

Related Discussions:- Determine number of coils and length of the spring, Assignment Help, Ask Question on Determine number of coils and length of the spring, Get Answer, Expert's Help, Determine number of coils and length of the spring Discussions

Write discussion on Determine number of coils and length of the spring
Your posts are moderated

Write your message here..

Related Questions

Machine design, The connecting rod of a four stroke cycle Diesel engine is ... The connecting rod of a four stroke cycle Diesel engine is of circular section and of length 550 mm. The diameter and stroke of the cylinder are 150 mm and 240 mm respectively. The

Slidercrank, connecting rod AB of length L support a variable compressiv fo... connecting rod AB of length L support a variable compressiv force F .Drive an expression for the moment of F about the crank axis O in the term of F L r and angle

Hot working and cold working process, different different

Head loss, calculate the head required calculate the head required

Applications of seam welding, Applications of seam welding Lap seam wel... Applications of seam welding Lap seam welding is used for the manufacture of cans, buckets and water tanks and for welding thin walled large diameter pipes. Mash seam welding

Boiler troble, cause effect remedies cause effect remedies

Lubrication, what are the necessity of lubrication ? what are the necessity of lubrication ?

Explain the meaning of a raft foundation, Explain the meaning of A raft fou... Explain the meaning of A raft foundation A raft foundation, as also combined footing, cannot be considered to be the opposite of a slab supported on the columns with a defined

Explain newtons law of cooling, Explain Newton's Law of cooling. What do yo... Explain Newton's Law of cooling. What do you mean by convective Heat Transfer coefficient ? What are the factors on which co-efficient of convective heat transfer (h) depends upon

Explain hard or fixed automation, Explain Hard or Fixed Automation Mech... Explain Hard or Fixed Automation Mechanical controls consist of numbers of mechanism that create the required relative motion to complete an activity. These mechanisms include: