Session: 01-02-03: Adaptive and Multifunctional Structures

Paper Number: 121164

121164 - High-Acceleration Mechanical Shock Characteristics of an Industrial Marine Fender 

Engineering systems are susceptible to intricate loading processes, such as accelerated mechanical shock, during handling, operation, and shipping. Shock is a sudden, erratic shift in acceleration that an object experiences because of an abrupt impact. The ability of an object to withstand the effects of mechanical shock on its structural integrity defines its crashworthiness. This paper presents the simulation study of the crashworthiness characteristics of a pre-used commercial marine fender including their peak accelerations (G_peak), shock energy absorptions and impact forces. Three test specimens of thicknesses 10 mm, 20 mm and 30 mm are modeled using the HyperMesh^TM software package. The peak acceleration responses of the specimens under half-sine shock waves at 50G, 60G and 70G are numerically determined using the LS-DYNA^® solver tool under linear dynamic loading. The shock waves are generated by dropping a 5-kg payload from heights ranging between 50 mm and 300 mm onto a padded shock seat for a pulse duration from 5 to 8 ms. The G_peak of the specimens are also experimentally measured and analytically computed to validate the numerical results. The shock energy absorptions and impact forces of the test specimens are calculated using analytical formulations. The effects of introducing tubular perforations in the specimens on the resulting peak accelerations and thereby the shock energy absorbing capacities are also investigated. The discrepancy between the simulated and experimental results decreases by an average of 55.1% with increasing thickness from 10 mm to 30 mm. The analytically determined G_peakagree well with the experimental values. It is found that the perforated specimens have lower G_peak, resisted smaller impact forces and absorbed up to 12% lesser energy per unit mass than their solid counterparts.

Presenting Author: David N. V. School of Engineering, College of Engineering, Universiti Teknologi MARA

Presenting Author Biography: David is currently an Associate Professor at the School of Mechanical Engineering, College of Engineering, Universiti Teknologi MARA (UiTM), Shah Alam, Malaysia. He earned his doctoral degree in Mechanical Engineering and Materials Science at Texas A&M University, USA under the auspices of Fulbright Fellowship, the Rice-Cullimore Scholarship – ASME Auxiliary, and the Malaysian Government. David obtained a Master of Science degree and a Bachelor of Engineering (Honors) degree in Mechanical and Materials Engineering from Universiti Kebangsaan Malaysia. He was the Head of International & Private Grants Acquisition Unit at the Research Management Center, UiTM between 2011 and 2019. During his tenure, the inflow of research funds increased 18-fold with grants obtained from more than 30 private and international funding bodies. The international and private grants registered the highest growth sector for grants acquisition across the UiTM system in 2017. He was honored with Excellent Service Award UiTM in 2004, 2015 and 2021. David is a member of the Board of Engineers, Malaysia and the American Society of Mechanical Engineers. David authored/co-authored over 100 refereed scientific articles and 11 book chapters as of August 2023. He was also the Chief Editor of two international conference proceedings and a special issue journal. David was the pioneering founder of and the first Managing Editor of the Scopus-indexed Journal of Mechanical Engineering published by UiTM Press. David consults scientific journal publishers on indexing solutions in major databases including Scopus, PubMed, Crossref and CLOCKSS. His research interests include bio-composites engineering, viscoelasticity, acoustics, structural health monitoring and pedagogical innovations. He has developed and tested a new iso-strain state composite model to characterize the uniaxial viscoelastic behavior of a natural rubber coated ballistic fabric. David also helped established the modified flipped-classroom to designing teaching instruction for remote and blended learning in UiTM.