Write down the design procedure to design a semi elliptical leaf spring
Answers
Answer:
As shown in the picture, the leaf spring or laminated leaf spring consists of a couple of full-length leaf and a number of graduated leaves. You can also observe from the picture of the leaf spring that the thickness of the whole spring is maximum at the centre and is gradually decreases towards the ends.
Formula to be used
Leaf spring design is based on the fundamental beam theory. I already have an article on how to design plates based on beam theory.
You have to use the following two formulas for the leaf spring design process:
Bending stress produced in the whole spring:
Tb= (3*W*L)/ (b*N*t^2)………………………………eqn1.1
Maximum deflection in the whole spring:
X= (6*W*L^3)/[{(2+(n/N)}*E*N*b*t^3]……………eqn1.2
Where,
Tb – maximum bending stress in the leaf spring
W – Applied load on the spring
t – Thickness of the individual leaves
X – Maximum deflection of the spring due to applied load
L – Span of the leaf spring
n – Number of full-length leaves
N – Number of graduated-length leaves
b – Width of the spring
E – Young’s modulus of the spring material
Leaf Spring Design Procedure
Let’s start with a leaf spring design problem. We have the following data as input:
W=24516N
L=0.445M
N=8
n=2
E=2.1E+11N/m2
X=0.13M
Sa=600000000N/m2
