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# Test: Fracture Mechanics & Thermal Stresses

## 10 Questions MCQ Test Machine Design | Test: Fracture Mechanics & Thermal Stresses

Description
This mock test of Test: Fracture Mechanics & Thermal Stresses for Mechanical Engineering helps you for every Mechanical Engineering entrance exam. This contains 10 Multiple Choice Questions for Mechanical Engineering Test: Fracture Mechanics & Thermal Stresses (mcq) to study with solutions a complete question bank. The solved questions answers in this Test: Fracture Mechanics & Thermal Stresses quiz give you a good mix of easy questions and tough questions. Mechanical Engineering students definitely take this Test: Fracture Mechanics & Thermal Stresses exercise for a better result in the exam. You can find other Test: Fracture Mechanics & Thermal Stresses extra questions, long questions & short questions for Mechanical Engineering on EduRev as well by searching above.
QUESTION: 1

### The critical value at which crack extension occurs is called

Solution:

Explanation: Fracture toughness is the critical value of stress intensity at which crack extension occurs.

QUESTION: 2

### Stress intensity factor is the critical value of stress at which crack extension occurs.

Solution:

Explanation: Stress intensity specifies the stress intensity at the tip of the crack.

QUESTION: 3

### The critical value at which crack extension occurs is called

Solution:

Explanation: Fracture toughness is the critical value of stress intensity at which crack extension occurs.

QUESTION: 4

Fracture toughness does not depend upon geometry of the part containing crack

Solution:

Explanation: Fracture toughness is directly proportional to a factor Y that depends upon geometry of the part having crack.

QUESTION: 5

How many modes are there for crack propagation?

Solution:

Explanation: Opening, sliding and tearing are the 3 modes.

QUESTION: 6

A curved beam has neutral axis is curved while loaded and straight when unloaded.

Solution:

Explanation: Curved beam’s neutral axis is always curved irrespective of the loading.

QUESTION: 7

A curved beam with eccentricity 0.02D is loaded with 1kN.Centroidal radius=4D and inner and outer radii are 3.5D and 4.5D respectively. Area of cross section is 0.8D². Find the dimension D if allowable stress is 110N/mm².Considering only bending stress.

Solution:

Explanation: σ(b)=Mh/ AeR or σ(b)=1000x4Dx(4D-0.2D-3.5D)/ 0.8D²x0.02Dx3.5D , σ(b)=21428.6/D²
21428.6/D² = 110 or D=13.95mm.

QUESTION: 8

A curved beam with eccentricity 0.02D is loaded with 1kN.Centroidal radius=4D and inner and outer radii are 3.5D and 4.5D respectively. Area of cross section is 0.8D². Find the dimension D if allowable stress is 110N/mm² and considering only direct tensile stress.

Solution:

Explanation: Direct Tensile Stress=1000/0.8D² or σ (t) =1250/D²
1250/D²=110 or D=3.4mm.

QUESTION: 9

The bending stress in a straight beam varies linearly with the distance from neural axis like that in a curved beam.

Solution:

Explanation: Bending stress in a curved beam varies hyperbolically with the distance from neutral axis.

QUESTION: 10

A curved beam with eccentricity 0.02D is loaded with 1kN.Centroidal radius=4D and inner and outer radii are 3.5D and 4.5D respectively. Area of cross section is 0.8D². Find the dimension D if allowable stress is 110N/mm² and considering combined effect of direct stress and bending stress.

Solution:

Explanation: σ(b)=Mh/ AeR or σ(b)=1000x4Dx(4D-0.2D-3.5D)/ 0.8D²x0.02Dx3.5D , σ(b)=21428.6/D²
DirectTensile Stress=1000/0.8D² or σ (t) =1250/D²
Total stress=22678.6/D² N/mm²= 110 or D=14.35mm.