B.E-B.E Aeronautical Engineering Composite Materials and Structures (Sathyabama University, Chennai, Tamil Nadu-2010)
Friday, 23 August 2013 01:46Duraimani
(Established under section 3 of UGC Act,1956)
Course & Branch :B.E - AERO
Title of the Paper :Composite Materials and Structures Max.Marks :80
Sub. Code :526701/626701 Time : 3 Hours
Date :05/03/2010 Session :AN
PART - A (10 x 2 = 20)
Answer ALL the Questions
1. What are prepregs?
2. What are the disadvantages of composite materials?
3. What are lamina and laminate? Define.
4. What is called monoclinic material? Give example.
5. List the assumption made in CLT.
6. List the failure modes of sandwich panel.
7. How many elastic constants are required to describe stress-strain relation for isotropic materials, orthotropic materials and anisotropic materials?
8. Define Micro mechanics and macro mechanics.
9. List the method used in Composite manufacturing.
10. What are the applications of composite materials in aircraft construction?
PART – B (5 x 12 = 60)
Answer All the Questions
11. Define stiffness and compliance matrix for an anisotropic materials and explain how it is transformed to orthotropic, monoclinic and isotropic materials.
(or)
12. Define composites. What are the advantages and disadvantages of composites? Explain its different application.
13. Explain generalized hooks law for 2D orthotropic lamina and obtain the transformed reduced stiffness matrix.
(or)
14. For a Graphite epoxy unidirectional lamina find the following (a) Compliance matrix (b) minor poisons ratio (c) reduced stiffness matrix (d) strains in the 1-2 co-ordinate system if the applied stress are
s1 = 2Mpa, s2 =-3Mpa t12 = 4Mpa
E1 = 181Gpa, E2 = 10.3Gpa, u12 = 0.28, G12 = 7.17GPA
15. Obtain the governing differential equation for unidirectional anisotropic plate and transform the equation for orthotropic plate.
(or)
16. Find the stiffness matrices [A] and [B] for 3 ply (0/30/60) Graphite epoxy lamina using classical lamination theory.
Assume E1 = 175Gpa, E2=23Gpa, u12=0.28, G12=12Gpa and each ply having thickness of 5mm
17. Obtain Flexural Rigidity for sandwich panel for the following condition
(a) Sandwich panel with same facing materials and different thickness
(b) Sandwich panel with different facing materials and different thickness.
(or)
18. Explain the failure modes of sandwich panel.
19. Write notes on the following
(a) Carbon fiber Manufacturing
(b) Filament winding
(or)
20. Explain the open and closed moulding processes used for composite manufacturing.
| Earning: ₹ 3.15/- |
