This set of Aerospace Materials and Processes online test focuses on “Aircraft Materials – Impact Test- Charpy Test”.
1. Which of the following are standard impact tests?
a) Izod test and flattening test
b) Izod test and Charpy test
c) Flattening test and reverse bend
d) Charpy test and reverse bend test
Explanation: The Charpy impact test and the Izod impact test are Standard impact tests. They have some differences, but they both give the impact values of the specimen. Reverse bend tests and flattening test are bending tests.
2. Which of the following impact test method is preferred these days?
a) Impact test
b) Reverse bend test
c) Flattening test
d) Charpy test
Explanation: The method commonly preferred these days is the Charpy impact test. The Izod impact test has also been extensively used in the past. It is rarely used for testing materials/specimen these days.
3. In the Charpy test, the tensile specimen being tested is ___________ on both sides.
Explanation: The tensile specimen in the Charpy impact test is threaded on both sides. One of the ends is threaded to the pendulum that is swinging. It is not axed, heated or subjected to any such treatment before being tested.
4. The Charpy test, which is a type of impact test measures the __________ absorbed by a specimen.
Explanation: The Charpy test, like an Izod test, gives the energy absorbed by the specimen/material being tested. This is used to obtain the comparative properties of the desired materials. It also tells if the material is extremely brittle.
5. In the Charpy test, the notch faces _________ from the pendulum.
Explanation: In the Charpy test, the notch faces away from the pendulum. This differs from the other impact test, the Izod impact test. This is one of the several differences between the two impact test methods.
Explanation: The above diagram represents a U-notch type specimen of a Charpy impact test. In this test method, there are primarily two kinds of test specimens. The U-notch test specimen and the V-notch test specimen.
7. The Charpy impact test does not require a pendulum/hammer.
Explanation: This statement is incorrect. Like an Izod impact test, even the Charpy impact test requires a pendulum/ hammer for the experiment. It is used to cause a rupture in the test specimen being tested.
8. The final impact value is obtained by dividing the _________ by the cross-sectional area in the Charpy test.
a) heat of the specimen
b) cross-sectional damage
c) energy of fracture
d) cross-sectional area
Explanation: There is a formula that is required to obtain the impact value from the test. In the Charpy impact test, it is found by dividing the Energy of fracture by the cross-sectional area of the specimen. The final Izod impact value is obtained by dividing the energy of fracture to the width of the specimen.
9. The swing of a pendulum/hammer decreases after it comes in contact with the specimen in a Charpy test.
Explanation: This statement is true. In fact, it is true for both the Izod impact test and Charpy impact test. Once the pendulum hits a specimen, it’s swing decreases significantly due to interruption in its path.
10. Which of the following affects a Charpy test?
a) Specimen gauges factor
b) Test machine frequency
d) Yield strength
Explanation: Several factors affect a Charpy impact test. Some of them include temperature, yield strength and fracture mechanisms. But the factors like colour and other irrelevant quantities are not important.
Sanfoundry Global Education & Learning Series – Aerospace Materials and Processes.
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