Stress and Strain | Mechanical Properties of Solids | Don't Memorise

TL;DR

This video explains the concept of stress and strain in physics and engineering, with a focus on beams made of different materials.

Transcript

do you know what a beam is there are many different meanings of this word in physics we use this word in two ways in optics we say a beam of light it can be thought of as a sequence of photons traveling in a straight line in mechanical engineering a beam is a long piece made of some material it can be a wooden beam a steel beam or a concrete beam w... Read More

Key Insights

• 😁 A beam can refer to a sequence of photons in optics or a long piece made of various materials in mechanical engineering.
• 😁 Stress in a beam is a result of interatomic and intermolecular forces caused by an applied force, and it is defined as force per unit cross-sectional area.
• 😁 Increasing the applied force on a beam increases its stress, while increasing the surface area decreases the stress.
• 🍉 Strain is the change in dimensions per unit of the original dimensions and can be calculated in terms of length, area, and volume.

Questions & Answers

Q: How is stress defined and calculated in the context of beams?

Stress is defined as force per unit cross-sectional area, calculated by dividing the applied force by the area of the beam's cross-section. It determines the extent of the uncomfortable state experienced by the beam.

Q: How does increasing the force applied to a beam affect its stress?

Increasing the force applied to a beam increases the stress it experiences. This is because stress is directly proportional to the force, while the cross-sectional area remains constant.

Q: What happens to the stress when the surface area of a beam is increased?

Increasing the surface area of a beam decreases the stress it experiences. This is because stress is inversely proportional to the area, so a larger area results in a lower stress for the same applied force.

Q: What is the SI unit of stress?

The SI unit of stress is the pascal (Pa), which is equal to 1 Newton per square meter (N/m²). Stress is measured in terms of force per unit area.

Summary & Key Takeaways

• The video explores the different meanings of the word "beam" in physics and mechanical engineering.

• It explains how a beam experiences stress when a force is applied to it, and how stress is defined as force per unit cross-sectional area.

• The concept of strain is introduced as the change in dimensions per unit of original dimensions, and examples of strain in terms of length, area, and volume are provided.