STRAIN ENERGY CONCEPT STRENGTH OF MATERIAL

strain energy and types of load like gradual loading, impact loading and sudden loading

1. SUBTOPIC -06 STRAIN ENERGY AND IMPACT LOADING Strain Energy :- when a body strained within elastic limit, energy stored in it. this energy is called strain energy. Strain energy= work done on a body .: u = x v Where, U= strain energy =stress V=volume of a bar The unit of strain energy is N.m.  

2. Resilience Total strain energy stored in body, within elastic limit is called resilience. Resilience= x v  

3. Proof Resilience The maximum strain energy that can be stored in a body at elastic limit is called proof resilience.  

4. Modulus of resilience(u m ) The maximum strain energy that can be stored in a body per unit volume at elastic limit is called modulus of resilience. The unit of modulus of resilience is N.mm/mm 3  

5. Instantaneous stress When a body is subjected to sudden load or Impact load the stress produced is called instantaneous stress.

6. Method of applying load

7. Gradual load The load is increasing gradually from zero to P. Stress,  

8. Sudden load When a body is subjected to total load P at a time, without small increments. It is called sudden load. Stress,  

9. Impact load When a load fall on a body from some height, it is called impact load. Strain energy is, u=work done u =P )  

10. = stress due to impact load = Impact load = height of fall of load = deformation of a body  

11. Derive equation of strain energy for gradual load In case of gradual load system, load gradually increases from zero to ‘ P’. = Now, Work done=average load X deformation = X = X      

12. V X V