Simple Stress & Strain | Strength of Material | Soumen Sir
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7 سال پیش
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This Video Tutorial will be
This Video Tutorial will be very helpful to our all BTech and Diploma Engineering Students.
Today we have learn "SIMPLE STRESSES & STRAIN" under Strength of Material.
LOAD (P): The external force acting on a body is called load. Unit- N
TYPES OF LOADS:- 1) Tensile loads 2) Compressive loads 3) Shearing loads 4) Twisting loads 5) Bending loads
STRESS (f) : The internal resistance developed in a material under the action of external force is called stress. Unit- f = P(Load) /A(Cross-Sectional Area) N/m2
TYPES OF STRESSES: 1.Tensile stress (ft) 2. Compressive(fc) 3. Shear stress(fs)
STRAIN (e): The deformation in a material under the action of external force is called strain.
Deformation i.e. Change in dimension
So, Strain = -------------------------------------------
Original dimension
TYPES OF STRAIN: -
1.Tensile Strain(et) : The strain produced in the member when subjected to tensile load is called tensile strain.
Tensile strain, et = ll/l (no unit)
2. Compressive strain (ec): The strain produced in the member when subjected to compressive load is called compressive strain.
Compressive strain, ec = ll/l (no unit)
3. shear strain (es): The strain produced in the member when subjected to shear load is called shear strain.
Shear strain, es = deformation / Original length
es = AA’ OR BB’ = radians
L
Volumetric strain (ev) : The strain produce in a body when subjected to forces tending to change the volume is called.
Volumetric strain = change in volume/ Original volume
= v / V
Elasticity: The ability of a material to regain its original position after the removal of force which causes its deformation is called elasticity.
Elastic limit: The limit upto which a material behaves as elastic material is called elastic limit.
HOOK’S LAW: It states that, “ when a material is loaded within its elastic limit, the stress is proportional to the strain.”
So, stress strain,
stress/strain = a constant.
Modulus of Elasticity or young’s modulus (E): The ratio of tensile stress and tensile strain( or compressive stress and compressive strain) is called modulus of elasticity.
So, modulus of elasticity, E = ft /et or fc/ ec
Modulus of Rigidity ( C, G, N ): The ratio of the shear stress to shear strain is called modulus of rigidity.
So, Modulus of rigidity, G = fs/es
Bulk or Volume modulus of elasticity (K): The ratio of the normal stress to the volumetric strain is called bulk or volume modulus of elasticity.
Bulk or Volume modulus of elasticity = Normal stress / volumetric strain
K= fn / ev
Relation between E, G, K are as under:-
E = 2G (1 + 1/m )
E = 3K ( 1- 2/m )
9GK
E = ----------------
3K + G
Longitudinal strain: When a bar is subjected to axial tensile force, the strain or deformation produced in the direction of the applied force is called the longitudinal strain.
So, Longitudinal strain = l / l l= increase in length, l= original length
Lateral strain: when a bar is subjected to axial loads, the strain produced perpendicular to the axis is called lateral strain.
Lateral strain = D – d / D where, D= original dia of bar, d= reduced dia of bar
Poissions’s ratio: The ratio of the lateral strain to longitudinal strain is called poission’s ratio.
So, poission’s ratio, = lateral strain / longitudinal strain = 1/m
If any query or suggestion then comment below.
And don't forget to support me by like, Subscribe and Share.
-----------------------
This Tutorial Video developed by Mr Soumen Chakrabarti, Faculty of Mechanical Engineering at Govt. Polytechnic, W.B., more than 25 years experience in teaching and CAD field. for any query, M- 9903023741
#Strength_of_Materials
#Simple_Stress_and_Strain
#Stress
#Strain
#Hookes_Law
Today we have learn "SIMPLE STRESSES & STRAIN" under Strength of Material.
LOAD (P): The external force acting on a body is called load. Unit- N
TYPES OF LOADS:- 1) Tensile loads 2) Compressive loads 3) Shearing loads 4) Twisting loads 5) Bending loads
STRESS (f) : The internal resistance developed in a material under the action of external force is called stress. Unit- f = P(Load) /A(Cross-Sectional Area) N/m2
TYPES OF STRESSES: 1.Tensile stress (ft) 2. Compressive(fc) 3. Shear stress(fs)
STRAIN (e): The deformation in a material under the action of external force is called strain.
Deformation i.e. Change in dimension
So, Strain = -------------------------------------------
Original dimension
TYPES OF STRAIN: -
1.Tensile Strain(et) : The strain produced in the member when subjected to tensile load is called tensile strain.
Tensile strain, et = ll/l (no unit)
2. Compressive strain (ec): The strain produced in the member when subjected to compressive load is called compressive strain.
Compressive strain, ec = ll/l (no unit)
3. shear strain (es): The strain produced in the member when subjected to shear load is called shear strain.
Shear strain, es = deformation / Original length
es = AA’ OR BB’ = radians
L
Volumetric strain (ev) : The strain produce in a body when subjected to forces tending to change the volume is called.
Volumetric strain = change in volume/ Original volume
= v / V
Elasticity: The ability of a material to regain its original position after the removal of force which causes its deformation is called elasticity.
Elastic limit: The limit upto which a material behaves as elastic material is called elastic limit.
HOOK’S LAW: It states that, “ when a material is loaded within its elastic limit, the stress is proportional to the strain.”
So, stress strain,
stress/strain = a constant.
Modulus of Elasticity or young’s modulus (E): The ratio of tensile stress and tensile strain( or compressive stress and compressive strain) is called modulus of elasticity.
So, modulus of elasticity, E = ft /et or fc/ ec
Modulus of Rigidity ( C, G, N ): The ratio of the shear stress to shear strain is called modulus of rigidity.
So, Modulus of rigidity, G = fs/es
Bulk or Volume modulus of elasticity (K): The ratio of the normal stress to the volumetric strain is called bulk or volume modulus of elasticity.
Bulk or Volume modulus of elasticity = Normal stress / volumetric strain
K= fn / ev
Relation between E, G, K are as under:-
E = 2G (1 + 1/m )
E = 3K ( 1- 2/m )
9GK
E = ----------------
3K + G
Longitudinal strain: When a bar is subjected to axial tensile force, the strain or deformation produced in the direction of the applied force is called the longitudinal strain.
So, Longitudinal strain = l / l l= increase in length, l= original length
Lateral strain: when a bar is subjected to axial loads, the strain produced perpendicular to the axis is called lateral strain.
Lateral strain = D – d / D where, D= original dia of bar, d= reduced dia of bar
Poissions’s ratio: The ratio of the lateral strain to longitudinal strain is called poission’s ratio.
So, poission’s ratio, = lateral strain / longitudinal strain = 1/m
If any query or suggestion then comment below.
And don't forget to support me by like, Subscribe and Share.
-----------------------
This Tutorial Video developed by Mr Soumen Chakrabarti, Faculty of Mechanical Engineering at Govt. Polytechnic, W.B., more than 25 years experience in teaching and CAD field. for any query, M- 9903023741
#Strength_of_Materials
#Simple_Stress_and_Strain
#Stress
#Strain
#Hookes_Law
7 سال پیش
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