Paper number 246
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ACOUSTIC EMISSION STUDIES DURING FATIGUE TESTING OF GFRP ELLIPTIC SPRING ELEMENTS |
S.K. Malhotra1, R. Krishnamurthy2, and M. Subramanian3
1Composites Technology Centre, Indian Institute of Technology, Madras,
Chennai - 600 036, India
2Department of Mechanical Engineering, Indian Institute of Technology, Madras,
Chennai - 600 036, India
3R & D Centre, Mahindra and Mahindra Ltd., Nasik - 422 007, India
| Summary | GFRP elliptic spring elements can be used for automotive suspension. GFRP spring elements were fabricated by Filament Winding method. Static stiffness of the spring element was 150 N/mm and major to minor axis ratio 1.5. Two types of laminate configurations were studied, viz-UD glass fibre/epoxy and UD glass fibre & woven glass fabric (alternate layers) / epoxy. Conventional epoxy modified with CTBN and cured with DDM or piperidine was used. Acoustic Emission studies were performed during fatigue cycling. Type of fatigue damage and rate of damage progression were evaluated from Acoustic Emission studies. Acoustic emissions are sensitive to failure mechanisms in composite laminates. Typical observations and analysis of Acoustic Emission signal characteristics during fatigue cycling are presented. |
Keywords | elliptic spring, fatigue, acoustic emission, glass fibre reinforced plastics, failure mechanisms. |