AE2030 - fatigue and fracture

Hindusthan College of Engineering and Technology Aeronautical Engineering Department Internal Exam – I Academic Year 2015-16

Class Year/Sem: IV/VII

Batch: 2012-16 AE2030 – FATIGUE AND FRACTURE

Date / Session: 30/07/2015 AN Part A

Total Marks: 50 Answer all the Questions

5 x 2 = 10 marks

1. What is stress concentration factor? 2. Define endurance limit? 3. Differentiate fatigue and fracture. 4. Define S-N curve. 5. What are the causes of fracture? Part B

Answer all the Questions

1 x 8 = 8 marks

1. (a) A component undergoes a cyclic stress of maximum 650 MPa and minimum 125 MPa. The component is made of steel with Sut = 900 MPa and Se = 400 MPa (S1000 = 1000 MPa) and undergoes fully reversed stress. Determine the life of the component. OR (b) Define Low Cycle Fatigue and High Cycle Fatigue with graph Part C

Answer all the Questions

2 x 16 = 32 marks

1. (a) Write about the modification factors for endurance limit OR (b) What are the effects of mean stress and explain the relations with diagram? 2. (a) Derive Coffin mansion relation OR (b) Determine the diameter of a sold circular rod of ductile material having endurance strength of 390 MPa and tensile yield strength of 520 MPa. The rod is subjected to a varying tensile load of 350 kN to 750 kN. The stress concentration factor is 1.5and assume the factor of safety as 2.2.

Name & Signature Staff In-charge

HoD/Aero

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