Part 2 Problem no. 6 on SFD and BMD - Shear Force and Bending Moment - Strength of Materials

TL;DR

This content provides a step-by-step guide on how to calculate shear force at different points of a beam and how to draw the shear force diagram.

Transcript

after this i will be calculating sf i'll say that this would be since i have point b here first i'll take the section just to the left of b to the left of b so if i see this is my section and to the left i have two forces one is r a upward other is 20 which is downward so r a is positive 20 will be negative so i have sf at point b is equal to 21 mi... Read More

Key Insights

• 👈 Shear force at a point is calculated by considering the forces to the left and right of that point.
• 😥 The vertical force component and its direction also affect shear force calculations at certain points.
• 😁 Shear force can change in magnitude and direction at different points along the beam.
• 😁 Shear force diagrams visually represent the variations in shear forces along a beam.
• 😁 The length of the shear force diagram matches the length of the beam.
• 😁 Shear force diagrams help in analyzing and understanding the distribution of forces in a beam.
• 😥 Shear forces at points without any loads or forces between them remain constant.

Questions & Answers

Q: How is shear force calculated at point B?

Shear force at point B is calculated by subtracting the force acting downwards (20 Newtons) from the force acting upwards (21 Newtons), resulting in a shear force of 1 kilo Newton.

Q: How is shear force calculated at point C?

Shear force at point C is calculated by subtracting the force acting downwards (20 Newtons) and the vertical force (30 sine 30 degrees), and adding the upward force (24 Newtons). This results in a shear force of 10 kilo Newtons at point C.

Q: Why is shear force at point D the same as shear force at point C?

Shear force at point D is the same as shear force at point C because there are no loads between points C and D. Thus, the forces acting on the beam remain constant, resulting in equal shear forces at both points.

Q: How is the shear force diagram drawn?

The shear force diagram is drawn by plotting the calculated shear force values at different points of the beam. The length of the shear force diagram is equal to the length of the beam. The diagram starts from point A, with a shear force of 21 kilo Newtons, and connects the plotted points with appropriate line segments.

Summary & Key Takeaways

• The content explains how to calculate shear force at points B, C, and D of a beam using the given loads and forces.

• Shear force at point B is calculated by considering the forces to the left and right of the point.

• Shear force at point C is calculated by considering the forces to the left and right of the point, as well as the vertical force acting at the point.

• Shear force at point D is the same as the shear force at point C since there are no loads between points C and D.