PPT: Shear Stresses in Beams

# PPT: Shear Stresses in Beams | Strength of Materials (SOM) - Mechanical Engineering PDF Download

``` Page 1

Topics To Be Covered
1. Shear Force
2. Shear Stresses In Beams
3. Horizontal Shear Stress
4. Derivation Of Formula
5. Shear Stress Distribution Diagram
6. Numericals
Page 2

Topics To Be Covered
1. Shear Force
2. Shear Stresses In Beams
3. Horizontal Shear Stress
4. Derivation Of Formula
5. Shear Stress Distribution Diagram
6. Numericals
Shear force
? Any force which tries to shear-off the
member, is termed as shear force.
? Shear force is an unbalanced force,
parallel to the cross-section, mostly
vertical, but not always, either the right or
left of the section.
Page 3

Topics To Be Covered
1. Shear Force
2. Shear Stresses In Beams
3. Horizontal Shear Stress
4. Derivation Of Formula
5. Shear Stress Distribution Diagram
6. Numericals
Shear force
? Any force which tries to shear-off the
member, is termed as shear force.
? Shear force is an unbalanced force,
parallel to the cross-section, mostly
vertical, but not always, either the right or
left of the section.
Shear Stresses
? To resist the shear force, the element will
develop the resisting stresses, Which is
known as Shear Stresses( ?).
?=                            =
Shear force
Cross sectional
area
S
A
Page 4

Topics To Be Covered
1. Shear Force
2. Shear Stresses In Beams
3. Horizontal Shear Stress
4. Derivation Of Formula
5. Shear Stress Distribution Diagram
6. Numericals
Shear force
? Any force which tries to shear-off the
member, is termed as shear force.
? Shear force is an unbalanced force,
parallel to the cross-section, mostly
vertical, but not always, either the right or
left of the section.
Shear Stresses
? To resist the shear force, the element will
develop the resisting stresses, Which is
known as Shear Stresses( ?).
?=                            =
Shear force
Cross sectional
area
S
A
Example:-
? For the given figure if we want to
calculate the ?..
? Then it will be
Let shear force be S
? ?=S/(bxd)
d
b
S
Page 5

Topics To Be Covered
1. Shear Force
2. Shear Stresses In Beams
3. Horizontal Shear Stress
4. Derivation Of Formula
5. Shear Stress Distribution Diagram
6. Numericals
Shear force
? Any force which tries to shear-off the
member, is termed as shear force.
? Shear force is an unbalanced force,
parallel to the cross-section, mostly
vertical, but not always, either the right or
left of the section.
Shear Stresses
? To resist the shear force, the element will
develop the resisting stresses, Which is
known as Shear Stresses( ?).
?=                            =
Shear force
Cross sectional
area
S
A
Example:-
? For the given figure if we want to
calculate the ?..
? Then it will be
Let shear force be S
? ?=S/(bxd)
d
b
S
Shear Stresses In Beams
? Shear stresses are usually maximum at the
neutral axis of a beam (always if the
thickness is constant or if thickness at
neutral axis is minimum for the cross
section, such as for I-beam or T-beam ), but
zero at the top and bottom of the cross
section as normal stresses are max/min.
NA
NA
NA
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## Strength of Materials (SOM)

37 videos|39 docs|45 tests

## FAQs on PPT: Shear Stresses in Beams - Strength of Materials (SOM) - Mechanical Engineering

 1. What is shear stress in beams?
Shear stress in beams refers to the internal force that causes one layer of the beam to slide or deform relative to adjacent layers. It is the result of transverse loading applied to the beam, causing a shearing effect on the cross-sectional area. Shear stresses are typically measured in force per unit area (N/m² or Pa) and play a crucial role in determining the structural integrity and stability of beams.
 2. How is shear stress calculated in beams?
Shear stress in beams can be calculated using the formula τ = VQ / Ib, where τ is the shear stress, V is the shear force, Q is the first moment of the area about the neutral axis, I is the moment of inertia, and b is the width of the beam. This formula accounts for the distribution of shear stress across the beam's cross-section and is derived from the shear stress distribution equation.
 3. What are the factors affecting shear stress in beams?
Several factors affect shear stress in beams. The primary factors include the magnitude and distribution of the shear force, the shape and size of the cross-section, and the material properties of the beam. Other factors such as the presence of holes, notches, or cutouts in the beam, as well as the type of loading (static or dynamic), also influence shear stress. Understanding these factors is crucial for designing beams that can withstand shear forces effectively.
 4. How does shear stress affect beam failure?
Shear stress plays a significant role in beam failure. When the shear stress exceeds the yield strength of the material, it can cause plastic deformation, leading to failure. Excessive shear stress can also result in shear cracks or shear buckling, reducing the beam's load-carrying capacity. It is essential to consider shear stress while designing beams to ensure they can withstand the expected loads without compromising their structural integrity.
 5. How can shear stress be minimized in beams?
To minimize shear stress in beams, several design strategies can be implemented. Increasing the beam's width or depth can help distribute the shear force over a larger area, reducing the shear stress. Reinforcing the beam with additional materials, such as steel plates or reinforcing bars, can also enhance its resistance to shear stress. Additionally, selecting materials with higher shear strength and optimizing the beam's cross-sectional shape can further minimize shear stress. Properly accounting for shear stress during the design phase is crucial to ensure the beam's overall strength and performance.

## Strength of Materials (SOM)

37 videos|39 docs|45 tests

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