# This gives 1 1 1 kb k ub kth 2 db e b kub 4 lub

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Unformatted text preview: g to separate the joint. Force on bolt: the bolt is in tension while the joint (members) being held together is in compression. Both the bolt and the joint are elas?c and can be modeled as linear springs. joint P = separa?on force Bolt and joint are ini?ally preloaded Fb = Fi + Ck P > 0 Ck = € δ= kb kb + k m € € € (Por?on of P carried by bolt) 0 ≤ Ck ≤ 1 Ck P (1 − Ck ) P = kb km Fb = Fi + Ck P € € Fm = −Fi + (1 − Ck ) P < 0 km Ck = k b − k b Ck € Tensile force on bolt € Fm = −Fi + (1 − Ck ) P Compressive force on bolt Bolt s?ﬀness If we neglect the bolt threads, we can approximate the bolt s?ﬀness with: 2 AE b πdb E b kb ≈ = Leff 4 Leff Eb … elas?c modulus of bolt A more precise calcula?on treats the bolt as 2 springs in series to account for the threaded € and unthreaded parts in the joint. This gives ȹ 1 ȹ −1 1 kb = ȹ + ȹ ȹ k ub kth Ⱥ 2 πdb E b kub = 4 Lub Tensile stress area (Tables 13.1, 13.2) € € € kth = At E b Lth Member s?ﬀness •  Treat members in...
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## This note was uploaded on 05/05/2012 for the course MANE 4030 taught by Professor Lucyzhang during the Spring '12 term at Rensselaer Polytechnic Institute.

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