Question

The aluminum rod AB (G=27 GPa) is bonded to the brass rod BD(G=39 GPa). Knowing that portion CD of the brass rod is hollow andhas an inner diameter of 40 mm, determine the angle of twist atA.

This seemed fairly straight forward, but my answer does notmatch the answer in the back of my book (which is6.02o). Oddly, my answer in radians seems to be off by afactor of 16. I cannot account for this. Help please? I always rateanswers.

Answer 1

The question requires using torsion formulas to find the angle of twist at point A in a composite rod made of aluminum and brass, and the discrepancy could be due to unit conversion error.

Step-by-step explanation:

The question is related to the angle of twist in composite rods of different materials, specifically aluminum and brass, subjected to torsion. Given the shear modulus (G) for both materials and relevant geometric data, the goal is to determine the angle of twist at a point A. The calculation involves using the torsion formulas for each material segment and summing the angles of twist for both the aluminum and brass rods. A possible error in the original calculation might come from an incorrect factor or unit conversion, especially since the student mentions being off by a factor of 16, which hints at an issue with the conversion between degrees and radians.