Exam Details
| Subject | Mechanics Design | |
| Paper | ||
| Exam / Course | B.Tech in Aerospace Engineering (BTAE) | |
| Department | School of Engineering & Technology (SOET) | |
| Organization | indira gandhi national open university | |
| Position | ||
| Exam Date | June, 2015 | |
| City, State | new delhi, |
Question Paper
Define alloy steel. Discuss the effects of nickel, chromium and manganese on steel.
Compare the weight, strength and stiffness of a hollow shaft of the same external diameter as that of solid shaft, the inside diameter of the hollow shaft being half the external diameter. Both the shafts have the same material and length.
List and explain the different types of welded joints.
A double riveted double cover butt joint in plates 20 mm thick is made with 25 mm diameter rivets at 100 mm pitch. The permissible stresses are
=120 MPa Ts =100 MPa =150 MPa.
Find the efficiency of the joint, taking the strength of the rivet in double shear as twice than that of single shear.
Explain in detail the overhauling of screw.
Find the diameter of a solid steel shaft to transmit 20 kW at 200 r.p.m. The ultimate shear stress for the steel may be taken as 360 MPa and a factor of safety as 8.
If a solid shaft is to be replaced by a hollow shaft, find the inside and outside diameter when the ratio of inside.to outside diameter is 0·5.
Classify different types of springs according to their shapes.
Design a leaf spring for the following specifications
Total load =140 kN
Number of springs supporting the load 4 Maximum number of leaves 10; Span of the spnng 1000 mm Permissible deflection 80 mm. Take Young's modulus, E 200 kN/mm^2 and allowable stress in spring material as 600 MPa.
What is meant by hydrodynamic lubrication? Explain in brief.
An 80 mm long journal bearing supports a load of 2800 N on a 50 mm diameter shaft. The bearing has a radial clearance of 0.05, mm and the viscosity of the oil is 0·021 kg/m-s at the operating temperature. If the bearing is capable of dissipating 80 determine the maximum safe speed.
Explain gear drives giving their merits and demerits.
A pulley made of grey cast iron FG 150, transmits 10 kW of power at 720 r.p.m. The diameter of the pulley is 500 mm. The pulley has four arms of elliptical cross-section, in which the major axis is twice of the minor axis. Determine the dimensions of the cross-section of the arm, if the factor of safety is 5.
7. A multiple disc clutch, steel on bronze, is to transmit 4·5 kW at 750 r.p.m. The inner radius of the contact is 40 mm and the outer radius of the contact is 70 mm. The clutch operates in oil with an expected coefficient of 0·1. The average allowable pressure is 0·35 N/mm^2. Find
The total number of steel and bronze discs
The actual axial force required
The actual average pressure
The actual maximum pressure
8. Write short notes on any four of the following:
Ergonomic consideration in design
St. Venant's theory
Self-locking screw
Fatigue design under combined stress
Tribology
Compare the weight, strength and stiffness of a hollow shaft of the same external diameter as that of solid shaft, the inside diameter of the hollow shaft being half the external diameter. Both the shafts have the same material and length.
List and explain the different types of welded joints.
A double riveted double cover butt joint in plates 20 mm thick is made with 25 mm diameter rivets at 100 mm pitch. The permissible stresses are
=120 MPa Ts =100 MPa =150 MPa.
Find the efficiency of the joint, taking the strength of the rivet in double shear as twice than that of single shear.
Explain in detail the overhauling of screw.
Find the diameter of a solid steel shaft to transmit 20 kW at 200 r.p.m. The ultimate shear stress for the steel may be taken as 360 MPa and a factor of safety as 8.
If a solid shaft is to be replaced by a hollow shaft, find the inside and outside diameter when the ratio of inside.to outside diameter is 0·5.
Classify different types of springs according to their shapes.
Design a leaf spring for the following specifications
Total load =140 kN
Number of springs supporting the load 4 Maximum number of leaves 10; Span of the spnng 1000 mm Permissible deflection 80 mm. Take Young's modulus, E 200 kN/mm^2 and allowable stress in spring material as 600 MPa.
What is meant by hydrodynamic lubrication? Explain in brief.
An 80 mm long journal bearing supports a load of 2800 N on a 50 mm diameter shaft. The bearing has a radial clearance of 0.05, mm and the viscosity of the oil is 0·021 kg/m-s at the operating temperature. If the bearing is capable of dissipating 80 determine the maximum safe speed.
Explain gear drives giving their merits and demerits.
A pulley made of grey cast iron FG 150, transmits 10 kW of power at 720 r.p.m. The diameter of the pulley is 500 mm. The pulley has four arms of elliptical cross-section, in which the major axis is twice of the minor axis. Determine the dimensions of the cross-section of the arm, if the factor of safety is 5.
7. A multiple disc clutch, steel on bronze, is to transmit 4·5 kW at 750 r.p.m. The inner radius of the contact is 40 mm and the outer radius of the contact is 70 mm. The clutch operates in oil with an expected coefficient of 0·1. The average allowable pressure is 0·35 N/mm^2. Find
The total number of steel and bronze discs
The actual axial force required
The actual average pressure
The actual maximum pressure
8. Write short notes on any four of the following:
Ergonomic consideration in design
St. Venant's theory
Self-locking screw
Fatigue design under combined stress
Tribology
Other Question Papers
Departments
- Centre for Corporate Education, Training & Consultancy (CCETC)
- Centre for Corporate Education, Training & Consultancy (CCETC)
- National Centre for Disability Studies (NCDS)
- School of Agriculture (SOA)
- School of Computer and Information Sciences (SOCIS)
- School of Continuing Education (SOCE)
- School of Education (SOE)
- School of Engineering & Technology (SOET)
- School of Extension and Development Studies (SOEDS)
- School of Foreign Languages (SOFL)
- School of Gender Development Studies(SOGDS)
- School of Health Science (SOHS)
- School of Humanities (SOH)
- School of Interdisciplinary and Trans-Disciplinary Studies (SOITDS)
- School of Journalism and New Media Studies (SOJNMS)
- School of Law (SOL)
- School of Management Studies (SOMS)
- School of Performing Arts and Visual Arts (SOPVA)
- School of Performing Arts and Visual Arts(SOPVA)
- School of Sciences (SOS)
- School of Social Sciences (SOSS)
- School of Social Work (SOSW)
- School of Tourism & Hospitality Service Sectoral SOMS (SOTHSM)
- School of Tourism &Hospitality Service Sectoral SOMS (SOTHSSM)
- School of Translation Studies and Training (SOTST)
- School of Vocational Education and Training (SOVET)
- Staff Training & Research in Distance Education (STRIDE)
Subjects
- Aerodynamics- I
- Aerodynamics- II
- Aircraft Design/Launch Vehicle/ Rocket Design
- Aircraft Instruments
- Aircraft Safety and Maintenance Engineering
- Aircraft Structures
- Aircraft Systems And Airworthiness Requirements
- Applied Chemistry
- Applied Physics
- Basic Control Theory
- CNS-ATM system
- Composite Materials
- Computer Fundamentals
- Engineering Drawing
- Environmental Science
- Flight Mechanics
- High Speed Aerodynamics
- Instruction To Computer Play Device
- Introduction to Aeronautics
- Introduction To Rocket And Missiles
- Mechanics Design
- Propulsion- I
- Propulsion- II
- Rocket Propulsion
- Space Dynamics
- Strength of Materials
- Technical Writing and Communication Skills
- Workshop Technology