Nondestructive Testing Method for Finding out the Defects in a Composite Liner

C. Muralidhar; Sheri George

doi:10.14429/dsj.49.3847

C. Muralidhar Defence Research & Development Laboratory, Hyderabad
Sheri George Defence Research & Development Laboratory, Hyderabad

DOI: https://doi.org/10.14429/dsj.49.3847

Keywords: X ray radiography, X ray computed tomography, Ultrasonic X ray radiography

Abstract

A composite liner of carbon phenolic has been inspected by ultrasonic, X-ray radiography andX-ray computed tomography (CT) to find defects like delaminations, debonds, voids, foreign inclusions, etc.The geometry, detection of multiple defects and porosity of the liner make ultrasonic testing (pulse-echo anddrycoupling) difficult for inspection. X-ray radiography being a non-contact technique finds multiple defectsbut compresses the structural information of 3-D volume into a 2-D image and interferes with overlyingand underlying areas of the object. X-ray CT generates an image of a thin and cross-sectional slice ofan object. R e linear attenuation coefficients in terms of Hounsfield values have been measured, comparedand correlated with CT images at the contrasts observed. 3-D images can be generated by stacking2-D cross-sectional images of the slices. These 3-D images can be cut at any angle of choice for mappingthe extent of delaminated/debonded areas. This type of information is difficult to obtain with conventionalnon-destructive testing techniques.

Author Biographies

C. Muralidhar, Defence Research & Development Laboratory, Hyderabad

Dr C Muralidhar obtained his PhD (Polymer/Ceramic Composites) from Indian Institute of Technology, New Delhi. He joined DRDO at the Defence Research & Development Laboratory(DRDL), Hyderabad, in 1988. He has been working in the field of nondestructive evaluation (NDE)of composite components since 11 years using various techniques, such as ultrasonic radiographyand thermography. Presently, he is working in a team, which is developing industrial computedtomography (ICT) for NDE analysis of various composite components. He has published 18 researchpapers in national and international conferences. One of his papers was awarded as the best technicalpaper at a national conference (NDE-98), held at Thiruvanthapuram in 1998. He has been conferredwith two DRDO Awards for his significant contribution in NDE of composites.

Sheri George, Defence Research & Development Laboratory, Hyderabad

Mr Sheri George obtained his BE (Mechanical Engineering) from Govt College of Engineering,Thiruvanthapuram, in 1992. He did his Masters in Computer Integrated Manufacturing from PSGCollege of Technology, Coimbatore, in 1995.. H e joined DRDL as Senior Research Fellow in 1995.He is a member of the team which is working on the indigeneous development of industrial computedtomography. He has published four research papers in international and national conferences. Oneof his papers was awarded as the best technical paper at a national conference (NDE-98) atThiruvanthapuram, in 1998.

References

Muralidha, C. Srinivasa Reddy, K. A study of delamination in a high silica glass phenolic cylindrical liner by ultrasonic, X-ray radiography and thermography techniques. Proceedings of the third International Workshop on Advances in Signal Processing for Nondestructive Evaluation of Materials, 5-8 August, 1997, Quebec, Canada, pp. 269-75.

Muralidhar, C. Debond study in an aluminum casing with composite liner using ultrasonic, X-ray radiography and X-ray computed tomography. Proceedings of the ASNT Fall Conference and Quality Testing Show, 19 23 October, 1998. Nashville, Tennesse, USA.