Question

Consider a cut thread bolt shown in Figure 8-17 of your textbook. The bolts are initially tightened by applying a torque to the nut to induce an initial axial preload for these fasteners. The clamped flanges of the steel housing each 1.25 inch thick. A 3/8-24 UNF SAE Grade 7 steel bolt is considered for this application. Bolt is 20% longer than the clamp length to allow sufficient protrusion for the nut. The external force on the bolted assembly is 1200 lbs. The bolt is meant to be replaced. PROBLEM 9 (TAA) The most likely preload is a) 6.1 kips b) 6.9 kips c) 7.4 kips d) 8.3 kips PROBLEM 10 (T4A) The bending stress at the root of the thread, as calculated in class, most likely is a) 37 ksi b) 47 ksi c) 98 ksi d) 125 ksi

Answer 1

Answers

Problem 9 - b) 9.6 ksi (refer solution details in the attachment)

Problem 10 - d) 125 ksi (refer solution details in the attachment)

Dated Solu hon Problem g (TAA) Graven Belt Peant to be replaced 3/8 24 UNE SAE Grade 7 Steel bolt As oo lt is & tandords, 8taern anea for 3le 24 0.0378 in2 Pre load 0.75x Areax ield sheng for replacas 03ie ba ts (Coeficent fo5 Ksi 6.FsX 0.0898 x tos 6.9Ksi 1 Problem Lo The bending sth at tx noot the thrand T-6P Π4 TTnd.p

P 1200 bs 1Mumber of threads Subiect to Sad -On do longer bolt than Clemp leg h will ubjet to ond 0.24 X 56(Threndsinch 14 deo.071 om Lminor from startarat ohameter t thread P: Pitch dianete YE D0 867 6.P .dp perdhiny 11 O38 XPachul (00 (as P for n=1 bxo.38x1200 txIxO.0771xo.0863 125 KS 1303 ksi