Important Answers: Stress, Strain and Deformation of Solids

STRESS, STRAIN AND DEFORMATION OF SOLIDS

1.       Define   Poisson’s   Ratio.

The negative ratio of lateral strain to the longitudinal strain is known as Poisson’s ratio.

2.       What is thermal Stress?

          If the expansion of a structural member is constrained, it will cause stresses to develop which are known as thermal Stress. 

3.   State   Hooke’sLaw.

The Ratio of stress to the strain with in elastic limit is known as Hooke’s Law.

4.       Define Bulk Modulus.

          The Ratio of direct stress to the corresponding volumetric strain is known as Bulk Modulus.

5.       Define Modulus of resilience.

Proof resilience per unit volume is defined as Modulus of resilience.

6. Define Elasticity.

It is the property of material to regain its original shape and dimensions on removing external load acting on it.

7. Give the relation between Modulus of Elasticity and Modulus of Rigidity.

The relation between modulus of elasticity and modulus of rigidity are as follows E= 2G(1+v)

8.       What is Strain Energy?

The Workdone is stored in rod and is known as strain energy.

9.       Define Proof Resilience.

          The maximum strain energy that can be stored in a body without permanent deformation is known as Proof resilience. 

10. Define compressive stress.

The Resistance offered by the section of member or body against the decrease in length due to applied pushing load.

11. Define: Bulk-modulus

The ratio of direct stress to volumetric strain is called as bulk modulus.. Bulk modulus, K = Direct stress / Volumetric strain

12. Define: Shear modulus or Modulus of rigidity

The ratio of shear stress to shear strain is called as bulk modulus.. Shear modulus, G = shear stress / shear strain

13. State the relationship between Young’sModulus and Modulus of Rigidity.

E = 2G (1+μ)

Where,

E - Young’s dulusMo G –Modulus of rigidity

μ- Poisson’s   ratio

14. Give the relationship between Bulk Modulus and Young’sModulus.

E = 3K (1-2μ)

V       Where,E - Young’s dulusMo

K - Bulk Modulus

μ- Poisson’s   ratio

15. What is principle of super position?

The resultant deformation of the body is equal to the algebric sum of the deformation of the individual section. Such principle is called as principle of super position

16. What is compound bar?

A composite bar composed of two or more different materials joined together such that the system is elongated or compressed in a single unit.

17. What you mean by thermal stresses?

If the body is allowed to expand or contract freely, with the rise or fall of temperature no stress is developed, but if free expansion is prevented the stress developed is called temperature stress or strain.

18. Define principle stresses and principle plane.

Principle stress: The magnitude of normal stress, acting on a principal plane is known as principal stresses.

Principle plane: The planes which have no shear stress are known as principal planes.

19. What is the radius of Mohr’scicle?

Radius of Mohr’scircle is equal to the maximum shear stress.

20. What is the use of Mohr’scicle?

To find out the normal, resultant and principle stresses and their planes.

21. List the methods to find the stresses in oblique plane?

1.       Analytical method

2.       Graphical method