Engineering Materials Lab Report 4 PDF

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Summary

Lab report....

Description

THINGS TO LOOK FOR:

What kind of testing machine was used? INSTRON Model 1332, capable of tension and compression. 3000 psi testing system. It is a Servohydraulic that uses oil.

What part of the testing machine moves during the test and what makes it move? Oil is put under pressure, 3000 psi. There is a controlled flow of oil into the actuator (cylinder) by the LVDT, making the machine frame move up.

What was the shape of the tensile specimen? Cylinder with narrow center and threaded ends.

What kind of fixtures held the sample? What kind of fixtures would be used if the specimen did not have threaded ends? Fixtures with threaded grip were used. If the ends were not threaded the appropriate grip would be a wedge grip, because it holds tighter the more the sample pulls on it.

How was the speed of testing controlled? The computer generates a ramp when the test starts, feedback of the errors is sent from the data being collected by the computer to the machine, which then controls how much oil is going into the LVDT, causing the machine to speed up or slow down depending on the chosen position control rate that was input on the computer. In this case, position control with rate of 0.25 in/min was used.

How was the elongation of the sample measured? Using an extensometer.

What is the function of the extensometer? The extensometer is attached to the sample in order to measure the elongation between the ends of the sample.

What data was taken? How was data recorded? The data was taken by the computer that generated a ramp indicating the stress and strain applied to the sample. Data was taken by recording stress and displacement.

Measuments: Diameter of the specimen before the test: d = 0.505 in Distance between grip faces: D = 2.575 in Diameter of specimen after the test: d = 0.300 in

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RESULTS:

Material Property

Stress vs Strain

Proportional Limit

47 ksi

Modulus of Elasticity

30,000

Yield

53 ksi

Tensile Strength

74 ksi

Rupture Strength

53 ksi

Rupture Strength (Actual)

Comments Labeled as A on Graph 1 part 1 Labeled as ME on Graph 1 part 1 Labeled as y on Graph 1 part 1 Labeled as TS on Graph 1 part 2 Labeled as RS on Graph 1 part 2 Calculation on page 5

Modulus of Resilience

0.03995

Calculation on page 5

Modulus of Toughness

26.6

Calculation on page 5 Calculation on page 5

Percent Reduction of Area

CALCULATIONS: 3

Modulus of Elasticity ( E )=

σ 40 −10 =30,000 = ∈ 0.0015−0.0005

Vcylinder = πr²h = π (0.2525)² (2.575) = 0.516 in³

Rupture Strength actual=¿

1 1 Modulus of Resilience= ∈PL . σ PL= ( 0.0017 )( 47 )=0.03995 2 2

Modulus of Toughness= A1 + A2 + A3 + A 4 1. 2. 3. 4.

bh (0.002 )(53 ) =0.053 = 2 2 A 2=bh= ( 0.010 −0.002 ) (51 ) =0.408 b ( 0.39−0.025 ) π h π( )(74 −53) 2 2 =6.02 = A 3= 2 2 A 4 =bh=( 0.39−0.01 ) ( 53) =20.14 A 1=

()

Modulus of Toughness=26.6

Percent Reduction of Area=¿

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