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Presentation onStrain Energy

By

Prof. V N Nikam

(LECTURER)

Email- vilas5151@gmail.com

Sandip Institute of PolytechnicSandip Foundation

Nashik

Strain Energy 8 Marks● Resilience or Strain Energy (U)

When a body made of an elastic material is loaded within elastic limit, the energy is stored in it is called as resilience or strain energy.

Strain energy U = (Ϭ2/2E) x V = (Ϭ2/2E) x A.l

Ϭ = stress produced in the body due to load

E = Modulus of elasticity

V = Volume of the

body l = Length of

body

A = c/s area

S I Unit = Joule or N-m● Proof Resilience ( U max)

The maximum amount of strain energy which can be stored by a member or body without exceeding the elastic limit is called as proof resilience.

Umax = (Ϭ2/2E) x V

● Modulus of resilience

Proof resilience per unit volume is called as modulus of resilience.Modulus of resilience = (Ϭ2/2E) x V / V = (Ϭ2/2E)

TYPES OF LOADINGS

Gradually Applied LoadDefn

:The type of loadingstart from zero and

slowly increasing uniformly is called as gradually applied load.

eg. Load applied in UTM

Suddenly Applied Load

Defn : When load is applied instantly on a body, then it is called as suddenly applied load

eg. Person entering into a lift.

Impact Load

Defn :When load is allowed to fall from a certain height, then it is called as impact load

eg. Load aplied on metal specimen in case on Izod & Charpy test.

Stress,

W = Impact Load in 'N'

H= Height of fall

L= Length of bar

A = C/S area.

Stress, Ϭ = 2P/A

P =Suddenly Applied Load orForce in 'N'

A = C/S Area

Stress, Ϭ = P/A

P = Gradually Applied Load or Force in 'N'

A = C/S Area