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Strength of Material

Strength of Material

Mechanical Properties
What are the Mechanical properties of materials in Engineering ...
  1. Hardness ;Resist the penetration (impact  load)
  2. Strength : Ability of material withstand of material without failure.
  3. Elasticity : It regain the original shape after removing load
  4. Plasticity : Permanent deformation after removing load.
  5. Mali ability : Converts to thin sheet without rupture
  6. Ductility : Draw in to thin wire.
  7. Brittleness : No deformation takes place & rupture (lake of ductility ) (cast iron)
  8. Toughness : absorb energy & plastic deformation without rupture.
  9. Fatigue: by repeatedly applied load program me and localized structure damage that occur.
  10. Creep : tendency of solid material to move slowly deform permanently under mechanical stress.
Strength of Materials (Part 1: Stress and Strain) - YouTube
Stress : Load applied on particular area.

  •  it is tensor quantity 
  • unit : N/mm2
Strain : Change in length to original length when force applied on body.

  • it has no unit.

Strength of Materials [ SOM ] Chapter wise Video Lectures ...

Strength of Material

Tensile : when body is subjected to equal and opposite pull.
Compressive : when body is subjected to equal and opposite push.
Thermal stress : stress due to change in temperature.
Linear strain : deformation of bar per unit length in direction of force.
Lateral strain : Direct stress dis accomplished strain in its own direction & opposite kind of strain in every direction at right angle is known.
Poison 's ration = Lateral strain / Linear strain

  • it has no unit
  • max poison ratio = 0.5 (rubber)
Bulk modulus: Body subjected to 3 mutually perpendicular stress of equal intensity
E = 9KC /(3K+C)

Principle stress & strain:

  • 3 planes are mutually perpendicular to each other
  • Carries direct stress only
  • No shear stress
  • 3 direct stress (Max, min, intermediate)
Mohr circle: Graphical method to find Normal tangential resultant stress.

Resilience: Strain energy stored in body due to external loading with in the elastic limit.

Bending Assumption :

  • Material is homogeneous.
  • obey hook's law.
  • Transverse section plane before and after bending.
  • Each layer is free to explained.
  • Value of young s modulus is same in tension and compression.

Strength of Material

Bending equation:
(M/I)=(SIGMA /Y)=(E/R),
M= Bending Moment
I = Moment of inertia
Y = Distance from center
E = Young 's modulus
R = radius of curvature 

Shear stress in shaft
(Tou/R) = (T/J) = (C x thita )/l
Tou =  Shear stress
R = Radius of shaft
T = torque
J = polar  moment
C = Rigidity
thita = angle of twist
l = length of shaft

Stiffness of spring : load required to produce unit deflection in spring is called stiffness of spring.
vipul baria
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Location: Vadodara, Gujarat, India

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