Torsion in Bars: Stress and Stiffness

This lecture delves into the analysis of torsion in bars, focusing on the relationship between torque and twist. The instructor explains the concept of torsional stress and its distribution in non-circular bars, emphasizing the importance of stress concentration factors. The lecture covers the calculation of reaction torques, angle of twist, and stress in bars under torsion, including scenarios where the material reaches its elastic limit. Additionally, the use of non-SI units for torque and power measurements is discussed, along with the application of stress-strain curves to determine the ultimate torque a shaft can withstand. The session concludes with a discussion on the upcoming midterm exam and the possibility of a review session for students.