MCQOPTIONS
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MCQOPTIONS
This section includes 10 Mcqs, each offering curated multiple-choice questions to sharpen your Mechanical Metallurgy knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
According to Irwin’s theory of crack resistance, the failure occurs when the rate of change of __________ release rate is equal to the rate of change of _______________ to the crack growth. |
| A. | strain energy, resistance |
| B. | resistance, plastic flow |
| C. | plastic flow, strain energy |
| D. | resistance, plastic flow |
| Answer» B. resistance, plastic flow | |
| 2. |
The R-curve is used to calculate the _______________ to fracture of the material during slow and stable crack propagation. |
| A. | increment |
| B. | resistance |
| C. | flow |
| D. | toughness |
| Answer» C. flow | |
| 3. |
For the evaluation of J-integral value from the compact tension specimen, the amount of J in the below-shown sample is equal to __________Where A = area under the load vs. displacement curveb=W-aB=Specimen thickness |
| A. | J=2A/Bb |
| B. | J=2ABb |
| C. | J=2AB/b |
| D. | J=A2/Bb |
| Answer» B. J=2ABb | |
| 4. |
If the crack length is doubled than the original value, the potential energy of the J integral will change by a factor of ____ |
| A. | 1 |
| B. | 2 |
| C. | 1/2 |
| D. | 4 |
| Answer» E. | |
| 5. |
The value of J integral in potential energy term is written as J=dUo/da=K2/E’. The value of E’ in case of plane stress is equal to ______ (where v is the poison’s ratio). |
| A. | E |
| B. | Ev |
| C. | E/v |
| D. | E2v |
| Answer» B. Ev | |
| 6. |
The J-Integral is interpreted as the potential energy difference between the two identically loaded sample having slightly different crack lengths. Mathematically it can be written as __________ |
| A. | J=dUo/da=K2/E’ |
| B. | J=dUo/da=K/E’ |
| C. | J=dUo/da=K2/E2 |
| D. | J=dUo/da=K/E |
| Answer» B. J=dUo/da=K/E’ | |
| 7. |
According to the J-Integral, the fracture occurs when the J integral value reaches a critical value. The value of J is equal to____________ |
| A. | \(\int(W dy-T \frac{du}{dx} ds)\) |
| B. | \(\int(W dy-T ds)\) |
| C. | \(\int(WT \frac{du}{dx} ds)\) |
| D. | \(\int(W dy+T \frac{du}{dx} ds)\) |
| Answer» B. \(\int(W dy-T ds)\) | |
| 8. |
The J integral is the path-dependent method. |
| A. | True |
| B. | False |
| Answer» C. | |
| 9. |
The J integral method is used for the _______________ materials. |
| A. | high strength plastic materials |
| B. | low strength ductile material |
| C. | low strength brittle material |
| D. | high strength brittle material |
| Answer» C. low strength brittle material | |
| 10. |
The geometry of the plastic zone in front of a crack tip is shown in the following figure. |
| A. | True |
| B. | False |
| Answer» B. False | |