Questions: Problem 3-1:
A concrete cylinder having a diameter of 6.00 in. and gage length of 12 in. is tested in compression. The results of the test are reported in the table as load versus contraction. Draw the stress-strain diagram using scales of 1 in. =0.05 ksi and 1 in. =0.2(10^-3) in./in. . From the diagram, determine approximately the modulus of elasticity.
Load (kip) Contraction (in.)
0 0
5.0 0.0006
9.5 0.0012
16.5 0.0020
20.5 0.0026
25.5 0.0034
30.0 0.0040
34.5 0.0045
38.5 0.0050
46.5 0.0062
50.0 0.0070
53.0 0.0075
Transcript text: Problem 3-1:
3-1. A concrete cylinder having a diameter of 6.00 in . and gage length of 12 in . is tested in compression. The results of the test are reported in the table as load versus contraction. Draw the stress-strain diagram using scales of $1 \mathrm{in} .=0.05 \mathrm{ksi}$ and $1 \mathrm{in} .=0.2\left(10^{-3}\right) \mathrm{in} /$ in. . From the diagram, determine approximately the modulus of elasticity.
\begin{tabular}{|l|l|}
\hline Load $($ kip) & Contraction (in.) \\
\hline 0 & 0 \\
\hline 5.0 & 0.0006 \\
\hline 9.5 & 0.0012 \\
\hline 16.5 & 0.0020 \\
\hline 20.5 & 0.0026 \\
\hline 25.5 & 0.0034 \\
\hline 30.0 & 0.0040 \\
\hline 34.5 & 0.0045 \\
\hline 38.5 & 0.0050 \\
\hline 46.5 & 0.0062 \\
\hline 50.0 & 0.0070 \\
\hline 53.0 & 0.0075 \\
\hline
\end{tabular}
Solution
Solution Steps
Step 1: Calculate Stress and Strain
The stress, \(\sigma\), is calculated using the formula:
\[
\sigma = \frac{\text{Load (kip)}}{\text{Area (in}^2\text{)}}
\]
The area, \(A\), of the cylinder is:
\[
A = \pi \left(\frac{d}{2}\right)^2 = \pi \left(\frac{6.00}{2}\right)^2 = 28.2743 \, \text{in}^2
\]
The strain, \(\epsilon\), is calculated using the formula:
\[
\epsilon = \frac{\text{Contraction (in.)}}{\text{Gage Length (in.)}} = \frac{\text{Contraction (in.)}}{12}
\]
Step 2: Calculate Stress and Strain for Each Data Point