Question

1. Lab Procedure

The cross-section dimensions of the 6061-T6 aluminum bar are 0.512 in x 0.248 in.

Attach the lead wires of the gages to the strain indicator as a quarter bridge circuit. (Note: the black and white lead wires are the common leads.)

Enter the gage factor (GF=2.11) into the strain indicator.

Record the specimen number (1, 2, or 3).

Balance the strain indicator and note the zero readings. Load the specimen according to the table below and record the strain values in the table below.

IMPORTANT: DO NOT EXCEED A MAXIMUM PRESURE OF 2500 lbs.

Specimen (pounds)		Axial Gage (microstrain)		Transverse Gage (microstrain)
0		0		0
500		406		-133
1000		815		-267
1500		1216		-396
2000		1656		-538
2500		2040		-661
0		42		-22

IMPORTANT: DO NOT EXCEED AXIAL FORCE OF 2500 lbs.

2. Lab Report

For each strain gage, construct a graph with load on the y-axis and net gage readings on the x -axis. Indicate if the gage readings are linear with force.

At each load level:

• Calculate Poisson’s ratio based on the strain readings
• Calculate the axial stress
• Calculate the modulus of elasticity based on the individual readings of axial stress and strain

Determine the average value of Poisson’s ratio and the modulus of elasticity. For 6061-T6, find accepted values of Poisson’s ratio, modulus of elasticity, and the yield stress.

		Poisson’s ratio from Experiment	Axial Stress from Force/Area	Modulus of Elasticity from Experiment	Material Properties (List Source for Accepted Values)
Pounds		avg=		avg=
0					E=
500					ν=
1000					Yield Stress=
1500
2000
2500
0

Answer 1