A 250 mm wide strip of 20 mm thickness is reduced to 18 mm in a single pass through a rolling process. the radius of each roller is 200 mm and its speed is 150 RPM. The strength coefficient for work material is 280 N/mm and the value of strain hardening coefficient is 0.15. The coefficient of friction between the workpiece and the rolls is 0.12. Find the roll force, torque and power required per roll.
Design Against Fluctuating Loads
Machine elements are subjected to varieties of loads, some components are subjected to static loads, while some machine components are subjected to fluctuating loads, whose load magnitude tends to fluctuate. The components of a machine, when rotating at a high speed, are subjected to a high degree of load, which fluctuates from a high value to a low value. For the machine elements under the action of static loads, static failure theories are applied to know the safe and hazardous working conditions and regions. However, most of the machine elements are subjected to variable or fluctuating stresses, due to the nature of load that fluctuates from high magnitude to low magnitude. Also, the nature of the loads is repetitive. For instance, shafts, bearings, cams and followers, and so on.
Design Against Fluctuating Load
Stress is defined as force per unit area. When there is localization of huge stresses in mechanical components, due to irregularities present in components and sudden changes in cross-section is known as stress concentration. For example, groves, keyways, screw threads, oil holes, splines etc. are irregularities.
Trending now
This is a popular solution!
Step by step
Solved in 2 steps
