Determine equivalent maximum shear stress in spring, Mechanical Engineering

Determine equivalent maximum shear stress in spring:

A close coiled helical spring contains a stiffness of 10 N/mm. Its length while fully compressed, with adjacent coils touching each other is 400 mm. G = 80 GPa.

(a) Find out the wire diameter and the mean coil radius, if their ratio is 0.02.

(b) If the gap among any two adjacent coils is 2 mm, what maximum load may be applied before the adjacent coils touch?

(c) What is the equivalent maximum shear stress in spring?

Solution

k = 10 N/mm, nd = 400 mm, G = 80 GPa = 80 × 103  N/mm2 , d = ?, R = ?,

d /R= 0.02  ∴R = 5d , Gap = 2 mm, W = ?, τmax  = ?

(a) k = W / Δ = G d 4/64 R3 n

            G d 4

∴ W/ Δ = G d 4/64 R3 n

or 10 =80 × 103 × d 4 / 64 (5d )3 . (400/d)

∴  d = 20 mm

R = 5d = 5 × 20 = 100 mm

n = 400/ d = 400 /20= 20

 (b) Gap between adjacent coils = 2 mm

Total gap = 2n = 2 × 20 = 40 mm, i.e. spring ought to deflect 40 mm if coils are to touch each other.

Δ= 64 W R3 n/ Gd 4

∴  40 = 64 × W × 1003 × 20 / 80 × 103 (20)4

or  W = 400 N

∴  τ max = 16 W R / π d 3 = 16 × 400 × 100 / π (20)3 = 25.5 N/mm

Posted Date: 1/21/2013 1:18:06 AM | Location : United States







Related Discussions:- Determine equivalent maximum shear stress in spring, Assignment Help, Ask Question on Determine equivalent maximum shear stress in spring, Get Answer, Expert's Help, Determine equivalent maximum shear stress in spring Discussions

Write discussion on Determine equivalent maximum shear stress in spring
Your posts are moderated
Related Questions
how bike''s hydraulic shock absorbers work?


expression for elongation of bar of conical section under the action of axial force p whenit tapers from d1 to d2 over a length

A motor cycle with rider, weight of 250 Kg., the centre of Gravity of the machine and rider combined being 60 cm above from ground level when the machine is standing upright. Each

Calculate mean effective pressure of engine: A 4 stroke diesel engine is having length of 20 cm and diameter of 16 cm. The engine is generating indicated power of 25 KW when

Example of Production Rate The turret lathe section contains six machines, all devoted to the production of the similar part. The section operates 10 shifts/wk. The number of

what is properties , uses and process ?

Evaluate the reactions at hinge and roller support: Q: A Force P = 5000N is applied at centre C of beam AB of length 5m as shown in figure given below. Find the reactio

Industrial Manufacturing Activity can broadly be divided into the followings ways: Mass Production Large lots e, g, Automobiles : In this the volume of production is very hi

Determine the maximum stress intensities: A rolled steel I-section, flanges 150 mm wide & 25 mm thick, web 200 mm long & 10 mm thick  is utilized to carry & axial load of 800