University:
Michigan State University
Course:
ERG 100 | Introduction to Engineering Design
Academic year:

2021
Views:

269

Pages:

1
Author:

Charlee Buchanan

PROBLEM 1.27 For the assembly and loading of Prob. 1.7, determine (a) the average shearing stress in the pin at B, (b) the average bearing stress at B in member BD, (c) the average bearing stress at B in member ABC, knowing that this member has a 10 × 50-mm uniform rectangular cross section. PROBLEM 1.7 Each of the four vertical links has an 8 × 36-mm uniform rectangular cross section and each of the four pins has a 16-mm diameter. Determine the maximum value of the average normal stress in the links connecting (a) points B and D, (b) points C and E. SOLUTION Use bar ABC as a free body. Σ M C = 0 : (0.040) FBD − (0.025 + 0.040)(20 × 103 ) = 0 FBD = 32.5 × 103 N (a) Shear pin at B where F τ = BD for double shear, 2A A= τ = (b) Bearing: link BD Bearing in ABC at B 4 d2 = π 4 (0.016)2 = 201.06 × 10−6 m2 32.5 × 103 = 80.8 × 10 6 (2)(201.06 × 10−6 ) τ = 80.8 MPa W A = dt = (0.016)(0.008) = 128 × 10− 6 m2 σb = (c) π 1 2 F BD A = (0.5)(32.5 × 103 ) −6 128 × 10 = 126.95 × 106 σb = 127.0 MPa W A = dt = (0.016)(0.010) = 160 × 10− 6 m2 σb = F BD 32.5 × 103 = = 203 × 106 −6 A 160 × 10 σ b = 203 MPa W