8/19/2019 Prof_S_K_Maiti

1/2

Topic :  Detection of Delamination Crack in Composite Machine Elements

Faculty Involved : Prof. S. K. Maiti (Guide) and S. S. Kulkarni (Co-Guide)

Many catastrophic accidents of engineered systems (see figure below) occur

 because of failure initiating at a single component level. This leads to lot of loss

to property and lives and disruption of services. To guard against such situations

‘Structural Health Monitoring (SHM)’ has become an important field. The

methods of SHM help to find out the status of degradation, or crack growth

through components. Of late, vibration based monitoring of component health

has become an area of intensive research. In this approach the vibration

response of components are regularly obtained and these are analysed to find

out the size and location of defect, or crack, so that timely preventive action can

 be taken.

Most of the studies done so far have considered detection of single and multiple

cracks in metallic components. Composite materials are abundantly used now a

day in aircrafts, ship building and automobiles. Though composites have higher

strength to weight ratio, they are weak against the development of delamination,

or inter-layer cracks. The detection of delamination, or cracks oriented parallel

to the longitudinal direction in beam like elements (see figure below) is a

challenge. This project is planned to address such a problem.

The project would involve analytical modelling, finite element analysis andexperiments. A couple of Ph.D. and PG students have already done some

ground work for the solution of the problem. The new student can benefit from

their works.

Students with good background in strength of materials, finite element method

and vibrations will have advantage to work on the problem.

For more details contact Prof S K Maiti (Room No. 310A, 2nd Floor of ME Dept)

8/19/2019 Prof_S_K_Maiti

2/2

PhD Topic: Hydrogen Assisted Stress Corrosion Cracking, Modelling and

Experiment

(2015 December)

Guiding faculty: Prof S K Maiti (Room 310A) and Prof D N Pawaskar

(Room 301B)

Annual loss to the exchequer of any country due to corrosion is quite

substantial. Out of this menace, the loss due to hydrogen assisted stress

corrosion cracking is quite substantial. Owing to the presence of hydrogen in

the environment surrounding a component, material loses its mechanical,

fracture and fatigue, properties. Traditionally, protection measures against the

evil were based on proper material selection, anti-corrosive coating, electro-

chemical methods, etc., or a combination of all these. Of late, substantial efforts

have been directed to understand the process of crack propagation and link the

degradation effects quantitatively to the changes in material mechanical

 properties and crack propagation characteristics. Majority of the investigations

reported on the issues so far deal with steel alloys. A wide band of machine and

structural constructions involves welded constructions. Welded zone behave

very differently than the virgin materials in relation to the hydrogen assisted

stress corrosion cracking (HASCC). Specially, the weld centre and heat affected

zone get affected in terms of the mechanical properties, hydrogen diffusivity

and crack propagation resistances.

The study of the HASCC involves investigation into the coupled processes of

hydrogen diffusion and crack propagation. In the proposed research project, the

diffusion process will be analysed using analytical and/or numerical methods.

The crack extension will be studied using the FE methods. Therefore, the work

will involve analytical modelling, FE modelling and/or use of FE software,

knowledge of fracture mechanics, and experimental methodologies. Candidates

with good academic record and strong interest in the areas are only welcome.