Bending and viscoelastic behaviour of delaminated woven E-glass/epoxy composite

ABSTRACT

In semi automated manufacturing processes of fibre reinforced composites, defects are induced between the plies. These defects cause reduction in service life of the products and lead to decrease in structural performance. To study the effect of induced defect on performance of composite, four types of woven E-glass/epoxy laminates with same fibre volume fraction were fabricated inserting circular and square PTFEs at the interfaces of 1–2 and 5–6 plies during hand layup. Each composite contained a single defect at selected interface. For these composites, flexural properties and viscoelastic properties were determined. The viscoelastic properties were investigated in a temperature range of 30°C–140°C using dynamic mechanical analyser. The flexural properties of intact composites are higher than those of delaminated composites. The location of delamination has more influence on flexural properties. The modulii determined from static flexural tests agreed with the storage modulii. The existence of artificial defect affected storage and loss modulii of delaminated composites. Moreover, the damping factor and loss shear modulus increased for delaminated composites.

KEYWORDS:

• Delamination
• flexural strength
• DMA
• storage modulus
• loss modulus
• damping factor

Disclosure statement

The authors declare that they have no conflict of interest.

Additional information

Funding

The present work is not funded by any organization.

Notes on contributors

Phaneendra Kumar Kopparthi

Phaneendra Kumar Kopparthi received his Ph.D in the year 2010 from Andhra University, Visakhapatnam, India in Mechanical Engineering. He has been contributing in teaching and administration since the year 2000 at Vignan’s Group of Institutions. He is presently working as Professor in the Department of Mechanical Engineering of Vignan’s Lara Institute of Technology & Science, Vadlamudi, Guntur District, Andhra Pradesh, India. His research interests are characterization of FRP composites, nano-composites, delamination studies of composites and optimization.

Kiran Kumar Yadav Aerra

Kiran Kumar Yadav Aerra received his M.Tech in the year 2011 from Jawaharlal Nehru Technological University Hyderabad, Hyderabad, India in Mechanical Engineering. He is presently Research Scholar at Vignan’s Foundation for Science, Technology & Research, Vadlamudi, Andhra Pradesh, India in the Department of Mechanical Engineering.

Bhaskara Rao Pathakokila

Bhaskara Rao Pathakokila received his Ph.D in the year 2017 from Andhra University, Visakhapatnam, India in Mechanical Engineering. He has been contributing in teaching since the year 1998. He is presently working as Professor in the Department of Mechanical Engineering of Vignan’s Lara Institute of Technology & Science, Vadlamudi, Guntur District, Andhra Pradesh, India. His research interests are characterization of FRP composites, delamination studies of composites, optimization and fatigue behaviour of composites.

Suresh Gamini

Suresh Gamini received his Ph.D in the year 2018 from National Institute of Technology, Warangal, India in Mechanical Engineering. He has been contributing in teaching since the year 2003. He is presently working as Professor in the Department of Mechanical Engineering of Vignan’s Foundation for Science, Technology & Research, Vadlamudi, Guntur District, Andhra Pradesh, India. His research interests are characterization of FRP composites, delamination studies of composites, tribology of nano-composites, non-linear vibrations and biomechanics.