CIVL 1101 - Assignment #4

Objective

The purpose of this assignment is twofold: first, you will get familiar with the fundamental ideas of stress and strain, and second, you will continue your study of engineering problem-solving.

You must hand in a copy of the cover sheet for the assignment and your solutions to Part 1 on engnieering paper. There are no Canvas submissions for this assignment.

Problems

Part 1: Consider the linear-elastic prismatic bar fixed on the left-hand side and loaded by axial forces P at the right-hand side, as shown in the figure below (assume all measurements are "exact"). In all cases, report answers to three significant figures.

1. If the allowable stress at failure for the material is σ = 15,000 psi and the applied load on the bar is P = 5,000 lb., what is the minimum area A required to prevent failure?
   
   
2. If the bar fails at strains ε > 0.03 and its original length is L = 30 in., what is the maximum allowable deformation δ before failure?
   
   
3. If the material in the bar is considered linear-elastic, the tensile stress  σ = 15,000 psi, and the tensile strain is ε = 0.01, what is the material's modulus of elasticity E?
   
   
4. If the original length of the bar is L = 10 ft. and it deforms  δ = 0.12 in., what is the stress  σ in the material if the modulus of elasticity E = 29,000 ksi?
   
   
5. Determine the cross-sectional area A of a steel cable required to support a 10,000 lb. tensile force over 100 ft. while not exceeding the allowable tensile stress of σ = 60,000 psi or a maximum elongation of δ = 0.1 ft. Assume the modulus of elasticity of steel is E = 29,000,000 psi.

Part 2. Read Chapter 2 in the Strategies for Creative Problem Solving by Fogler and LeBlanc.