The spring above is being considered for use on a hobby hors

The spring above is being considered for use on a hobby horse. The length to the inside ends is 5 1/2 inches. The outer diameter is given as 1 1/16 inches. The wire size is 0.120 inches. Assume the spring is made from ASTM 227 steel. The hobby horse mounts to its frame using 4 extension springs. On the mounting frame and on the hobby horse there are matching eye hooks. The mounting distance is given as 5.75 inches between the inner surfaces of the mounting eye hooks. The hobby horse weighs 10 lbs. Using Example 18-4 from the text book as a guide, answer the following questions: a. What gage wire is this? b. What is the mean diameter Dm? c. What is the inner diameter ID? d If the loop diameters = ID, what is the Body Length of the spring? e. Based on the full life and assuming the active number of coils is one less than the actual total, what is the number of active coils? f. What is the spring index C? g. What is the value of the Wahl constant K? h. What is the spring force k in lb/in? i. What is the initial load and stress when the spring is installed? What is the preferred range of the initial stress? j. Will the initial load hold the 10 lb hobby horse or will the horse sag? k. If the spring can deflect 2 inches beyond the initial install length, what is the total load/spring and the total load being carried by all four springs? I. What is the shear stress in each spring at maximum load? What is the allowable maximum load for severe service? m. Based on this analysis, is the spring acceptable to carry a 50 lb child?

Solution

There were too many subparts in question to clearly indicate all the calculations. so please revert to me if you want detailed calculations for any answer of the subpart.

a) gage of this wire is AWG 8 as per given wire dia

b) Mean diameter is 0.943 in

c) inner diameter ID = 0.823 in.

d) Body length is 3.855in

e) Number of active coils = 31.125

f) Spring index is 7.854

g) Wahl constant is 1.188

h) spring force 11.4311 lb/in

i) initial tension 10.4331 lbf

for solving other questions, the solution of example 18-4 from text book is required.