Tensile Testing – Data Sheet

Tensile Testing – Data Sheet

Please fill in your name, group members, data and instructor’s name

Mark gage length indents using the hammer

Measure the original diameter and gage length

Material is 2024-T351 Al alloy

Today’s Specimen 2024-T351 Aluminum Alloy Contains ~94% (Al), ~4.5%(Cu),

1.5% (Mg) Used in aircraft fittings, gears and

shafts, missile parts, veterinary and orthopedic equipment

You can use info for 2024-T3 for comparison

Data Sheet

Data Sheet (continued)

After Testing Record load & strain when

extensometer was taken off Record maximum load and approximate

load at yield Measure final diameter and gage length Record data filename Either sketch or photograph the

fractured surfaces Compute the parameters on the reverse

side of data sheet

Data Sheet

Lab Report #2: due next week Cover Page + Abstract (10 points) Data Sheet (5 points) Spreadsheet of Raw/Processed Data Relevant Plots (20 points) Materials Properties Table (5 points) Comments and Conclusions (15

points)

Tensile Properties

Quantitative determination of Elastic Modulus, E Proportional Limit, PL

0.2% Offset Yield Strength, Y

Tensile Strength, TS

% Elongation to Failure, %f

Modulus of Toughness, Atotal

Qualitative study of Failure

Tensile Testing –Processing Data Importing data into Excel Correcting data for physical slack Setting up the spreadsheet Computing stresses and strains Entire stress-strain curve Elastic portion and modulus Proportional limit and yield strength Modulus of Toughness Fitting spreadsheet into one page Lab Report Template

Importing Data into Excel In Excel: File Open (choose file) Dialog: Do you want to open the file now?

click on “Yes” button Steps 1-3: click Next Next Finish

Correcting data for initial slack Identify a row when both strain and

force increase monotonically (in our case row 550) : see next two slides

{it may help to plot the data up to ~2000lb}

Subtract this initial strain and force value from each subsequent row (in our case: 0=2.05E-02%, F0=1.05E+03 lb)

See next two slides

Identifying the New Origin

Strain = 2.05E-02Force = 1.50E+03

Correcting Raw Data

=A550-$A$550

=B550-$B$550

3 decimal digits

0 decimal digits

Format Data and Plots Load in lbs - 1 decimal digit Strain in % - 3 decimal digits Stress in psi – 0 decimal digits Strain in in/in – 2 decimal digits (sci

notation) Energy in psi - 2 decimal digits (sci

notation) Format one row; then COPY + PASTE

SPECIAL (format only) to other rows Check axis scales in all the plots Print the plots before hiding rows

Spreadsheet Setup In a New Worksheet Set up cells as shown below

A0 = D0

2/4

Af = Df2/4

Compute Stresses & Strains Copy & Paste Special (Values & Formats only)

“corrected” data Compute stress & strain for first row

=%strain/1002 dd sci

=Load/A0

0 dec digits

= (1 + )0 dec digits

= Ln(1 + )2 dd sci

Stresses & Strains Format strain cells (scientific, 2

decimals) Format stress cells (number, 0 decimal) Copy formulas for each subsequent row {Note true stress & strain formulas are

valid only up to the maximum load}

Plot Stress-Strain Curves Select data in columns C, D, E & F Plot smooth curves (no data markers) Move the chart to a new worksheet Delete gridlines Adjust True Stress curve so that it is

plotted against data in column E (see next slide)

Adjust axis titles and values (see the plot)

Adjusting True Stress Curve

Right Click on plot Select Data…

Adjusting True Stress Curve Replace “C” by “E” in “Series X Values” box

Stress-Strain Curves

Elastic Modulus Select data in columns C & D up to a

stress value that shows linearity Plot data markers Move chart to a new worksheet Delete gridlines Fit a straight line thru’ the origin Format the plot labels, axes and line-fit

results as appropriate (see next slide)

Elastic Modulus Plot Enter E = 29.60 Msi in cell I5 Select data points by

clicking on any and then Right-click and choose “Add Trendline”

Proportional Limit and0.2% Offset Yield Strength In column H, enter formula: = E * Engg Strain Adjust format, and copy it down until the

stress value slightly exceeds Engg Stress In column G, beginning at row where Engg

Strain slightly exceeds 0.002 (-0.2%), enter formula: = E * (Engg Strain – 0.002)

Adjust format, and copy it down until the stress value slightly exceeds Engg stress

Proportional Limit and Yield Strength

Elastic Modulus, Em

= Em * EStrain

Stop 69702 > 64779

Begin at Estrain = 0.002

= Em * (Estrain – 0.002)

Stop 78643 > 75792

Plot Curve & Lines Plot data in columns C, D, G, H

(smooth curves, no data markers) Format plot labels, axes etc. (see

next slide)

Proportional Limit and0.2% Offset Yield Strength

Data Point @ failure

same

Strain Energies and Modulus of Toughness

Modulus of Toughnessusing Trapezoidal Rule {Note no entry in Row 13} Enter formula for width: =C14 – C13 Enter formula for average height:

= (D14 + D13)/2 Enter formula for area: = I14 * J14 Adjust formats, and copy all formulas

down to the last row (point@failure) Modulus of Toughness is the sum of all

area values (see next slide)

Modulus of Toughnessusing Trapezoidal Rule

= C14 – C132 dd sci

= (D14 + D13)/20 dec digits

=I14 * J142 dd sci

Materials Property Tables

TriangularArea

Comparison with Lab #1

Adjust Spreadsheet of data to fit one page by hiding rows

Format Data and Plots Load in lbs - 1 decimal digit Strain in % - 3 decimal digits Stress in psi – 0 decimal digits Strain in in/in – 2 decimal digits (sci

notation) Energy in psi - 2 decimal digits (sci

notation) Format one row; then COPY + PASTE

SPECIAL (format only) to other rows Check axis scales in all the plots Print the plots before hiding rows

Lab Report Grading Rubric ..1

Lab Report Grading Rubric ..2

Lab Report Grading Rubric ..3

Lab Report due next week {note that when you hide rows, it may

distort your plots} Answer multiple-choice questions and

student survey ONLINE before the due-date

Review your lab report before submitting in the box under your mailfolders

Select box “MECE-204: Strength Lab”