Anna University Composite Materials Model Test Paper

 Anna University Composite Materials Model Test Paper

VI SEMESTER- COMPOSITE MATERIALS

METALLURGICAL ENGINEERING

 

TIME – 3 Hours                                                                    MAXIMUM : 100 Marks

PART – A                     (10 x 2 = 20 Marks)

ANSWER ALL QUESTIONS

1.Give the maximum temperatures upto which polymers, metals and ceramics can be used as matrix materials.

2.Draw neat sketches for (i) fiber  (ii) particulate and (iii) laminar composites and mark the different constituents.

3.What are the advantages of ceramics over metals as fibers?

4.What is a composite fiber? Give one example.

5.Draw a schematic sketch for production of metallic fibers by Taylor’s process.

6.Give two applications for composites in biomedical applications.

7.Give the relationship between particle size and volume fraction in a dispersion strengthened composites.

8.List two physical properties that can be estimated using rule of mixtures.

9.What are hybrid composites? Give one example.

10. Name two composite structures subjected to

(i) creep and (ii) fatigue loading.

PART – B                (5 X 16 = 80 Marks)

 

11.a)Discuss the classification of composite materials.

Give examples for each class.                                                                         (8)

 

b) What are directionally solidified eutectics? Discuss with an example

the production, properties and applications of DSE’s.                                (8)

 

12. a) (i) Discuss the production of glass fibers in detail using a neat sketch.

Give the composition of E glass and S glass.                                          (8)

(ii) Compare the properties of metals, ceramics and polymers as matrix materials.                                                                                              (8)

( OR )

 b) (i) Explain how (i) high modulus and (ii) high strength carbon fibers prepared.                                                                                                (8)

(ii) Briefly discuss the various fracture modes in fiber composites.           (8)

 

13.a) (i) What are interfacial reactions in composites?

Why are they important?

What are the factors that affect interfacial behavior in composites?       (8)

 

(ii) Discuss the tensile behavior of continuous and discontinuous

fiber composites briefly.                                                                                   (8)

( OR )

 b) (i) Discuss the functions of matrix and dispersed phase in fiber

reinforced and particle reinforced composites.                                            (8)

 

(ii) Explain how fine particles in a dispersion strengthened composite

influence its creep behavior.                                                                       (8)

 

14. a) (i) What are honeycomb structures? What are the functions of

core and facing material in a honeycomb. Give examples and applications of honeycomb. Give examples and applications of honeycomb structures.                                                                                   (8)

 

(ii) Explain briefly any two methods used for producing laminar

composites. Give examples and applications for laminar

composites.                                                                                           (8)

( OR )

b)(i) Discuss any two important techniques for MMC’s.                                    (8)

 

(ii) Discuss the important applications of composites in aerospace

and automobiles.                                                                                            (8)

 

15. a)(i) What is Rule of Mixture? Explain

A unidirectional Kevlar 49 fiber-epoxy composite contains 60% by volume of Kevlar   40% fibers and 40% epoxy resin.  The density of

the Kevlar 49 fibers is 1.48 Mg/m3 and that of the epoxy resin is

1.20 Mg/m3.  (a) What are the weight percentages of Kevlar 49

and epoxy resin in the composite material and (b) what is the

average density of the composite?                                                            (8)

 

(ii)  Discuss the behavior of fiber composites under compressive loads.                  (8)

 

b.(i) Derive the Rule of mixtures to predict the elastic modulus for an

aligned and continuous fiber composite with loading (i) parallel

(ii) perpendicular to fiber alignment.                                                              (8)

 

(ii)  Discuss the (i) fatigue and (ii) impact behavior of composites with

suitable  example.                                                                                             (8)

 

 

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