+ High-strength bolts are used in the construction of many steel structures. For a given bolt, the required minimum bolt tension is 36 kips. Assuming the coefficient of static friction to be 0.30, determine the required couple (lb-ft) that should be applied to the bolt an nut. The mean diameter of the thread is 2.17 in., and the lead is 0.185 in. Neglect friction between the nut and washer, and assume the bolt to be square-threaded. Given: • minimum bolt tension is 36 kips ("W" in diagram" • coefficient of static friction 0.30 find friction angle, th=ArcTan[us] • mean diameter of the thread is 2.17 in → r = diameter/(2*12), change to feet • lead is 0.185 in. → change to feet, find wedge angle, th = ArcTan[L/(2 Pi r)] Find: • the required couple (lb-ft) that should be applied to the bolt and nut couple = M = r*Q → change inches to feet, kips = 1000 lbs

+ High-strength bolts are used in the construction of many steel structures. For a given bolt, the required minimum bolt tension is 36 kips. Assuming the coefficient of static friction to be 0.30, determine the required couple (lb-ft) that should be applied to the bolt an nut. The mean diameter of the thread is 2.17 in., and the lead is 0.185 in. Neglect friction between the nut and washer, and assume the bolt to be square-threaded. Given: • minimum bolt tension is 36 kips ("W" in diagram" • coefficient of static friction 0.30 find friction angle, th=ArcTan[us] • mean diameter of the thread is 2.17 in → r = diameter/(212), change to feet • lead is 0.185 in. → change to feet, find wedge angle, th = ArcTan[L/(2 Pi r)] Find: • the required couple (lb-ft) that should be applied to the bolt and nut couple = M = rQ → change inches to feet, kips = 1000 lbs

International Edition---engineering Mechanics: Statics, 4th Edition

4th Edition

ISBN:9781305501607

Author:Andrew Pytel And Jaan Kiusalaas

Publisher:Andrew Pytel And Jaan Kiusalaas

Chapter7: Dry Friction

Section: Chapter Questions

Problem 7.49P

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