How Do You Calculate the Compression of Aluminum and Brass Rods Under Force?

Click For Summary
SUMMARY

The discussion focuses on calculating the compression of aluminum and brass rods under a compressive force of 8400N. The rods, each measuring 0.45m in length and 1.5cm in diameter, experience a combined length decrease of 0.55mm. Participants clarify that the Young's modulus of each material should not be combined; instead, the compression for each rod must be calculated separately before summing the results. The correct approach involves determining the individual compressions based on the material properties and applying the formula for compression.

PREREQUISITES
  • Understanding of Young's modulus for aluminum and brass
  • Knowledge of the formula for calculating compression under force
  • Familiarity with cross-sectional area calculations
  • Basic principles of material mechanics
NEXT STEPS
  • Research the Young's modulus values for aluminum and brass
  • Learn the formula for calculating compression: ΔL = (F * L) / (A * E)
  • Explore how to calculate the cross-sectional area of cylindrical rods
  • Study the principles of composite material behavior under load
USEFUL FOR

Mechanical engineers, materials scientists, and students studying mechanics of materials will benefit from this discussion, particularly those interested in understanding the behavior of different materials under compressive forces.

Lalasushi
Messages
11
Reaction score
0
"2 rods of equal length (0.45m) and diameter (1.5cm) are placed end to end. one rod is aluminium, the other is brass. if a compressive force of 8400N is applied to the rods, how much does their combined length decrease?" [ans: 0.55mm)

with this question, I am not sure whether its ok to find the compression of each of the rods separately first, then add the answers together to get the combined length decrease because i couldn't get the right answer that way...and i don't know if its ok to add the 2 young's modulus for the 2 materials together and then treat it as one material...can anyone help me out here?
 
Physics news on Phys.org
Your first method should have worked. Did you find the areas? You cannot add the moduli of the two materials first. Show what you did and someone will find where you went wrong.
 
Hint: You need to calculate the decrease in length for two rods individually and then add the compressions of both.

BJ
 

Similar threads

Confusion Calculating Young's Modulus
  • · Replies 5 ·
Replies
5
Views
2K
How Do Mass and Young's Modulus Affect Cylinder Stability?
  • · Replies 1 ·
Replies
1
Views
2K
How Does Young's Modulus Affect the Elongation of Composite Rods?
  • · Replies 1 ·
Replies
1
Views
6K
How Does Temperature Affect the Fit Between a Brass Ring and an Aluminum Rod?
  • · Replies 1 ·
Replies
1
Views
2K
Young's Modulus: Vibrations in a rod
  • · Replies 3 ·
Replies
3
Views
3K
Calculating Force on a Stretched Steel Rod | Young's Modulus 200*109 Pa
  • · Replies 1 ·
Replies
1
Views
3K
Determine the modulus of elasticity, Poisson's ratio and the shear modulus.
  • · Replies 1 ·
Replies
1
Views
8K
How Does Young's Modulus Differ from Spring Constant in Shape and Geometry?
  • · Replies 10 ·
Replies
10
Views
7K
Calculating Speed of Sound in Nickel using Atomic Properties
  • · Replies 5 ·
Replies
5
Views
6K
How Do You Calculate Young's Modulus from Tensile Stress and Strain Data?
  • · Replies 23 ·
Replies
23
Views
2K