A Novel and Highly Effective Natural Vibration Modal Analysis to Predict Nominal Strength of Open Hole Glass Fiber Reinforced Polymer Composites Structure

Mohammed Y Abdellah; Mohamed K Hassan; Ahmed F Mohamed; Khalil Abdelrazek Khalil

doi:10.3390/polym13081251

A Novel and Highly Effective Natural Vibration Modal Analysis to Predict Nominal Strength of Open Hole Glass Fiber Reinforced Polymer Composites Structure

Polymers (Basel). 2021 Apr 12;13(8):1251. doi: 10.3390/polym13081251.

Authors

Mohammed Y Abdellah^{1

2}, Mohamed K Hassan^{1

3}, Ahmed F Mohamed^{1

4}, Khalil Abdelrazek Khalil^{5

6}

Affiliations

¹ Mechanical Engineering Department, College of Engineering and Islamic Architecture, Umm Al-Qura University, Makkah 21955, Saudi Arabia.
² Mechanical Engineering Department, Faculty of Engineering, South Valley University, Qena 83521, Egypt.
³ Production Engineering & Design Department, Faculty of Engineering, Minia University, Minia 61111, Egypt.
⁴ Mechanical Engineering Department, Faculty of Engineering, Sohag University, Sohag 82524, Egypt.
⁵ Mechanical and Nuclear Engineering Department, College of Engineering, University of Sharjah, Sharjah 27272, United Arab Emirates.
⁶ Mechanical Design and Materials Department, Faculty of Energy Engineering, Aswan University, Aswan 81521, Egypt.

Abstract

Glass fiber reinforced polymer (GFRP) composite laminates are considered the key material in many industries such as the infrastructure industries and the aerospace sector, and in building structures due to their superior specific strength and lightweight properties. The prediction of specimens' nominal strength with open holes is still an attractive and questionable field of study. The specimen size effect is referred to its strength degradation due to the presence of holes when specimen geometry gets scaled. The non-destructive test used to measure the nominal strength of such material is a great tool for fast selection purposes, but not secure enough for several purposes. Furthermore, the destructive tests which are more expensive and time-consuming should be avoided in such structures. The present work aims to predict the nominal strength of open-hole GFRP's composite using modal analysis of their natural frequency as non-destructive tests. At this end, the natural frequency, which is measured using modal analysis procedures, is combined with both linear elastic fracture mechanics (LEFM) and the theory of elasticity to predict the nominal strength of open-hole composite laminates. This advanced model employs two parameters of surface release energy resulting from a simple tension test and Young's modulus based on vibration modal analysis. It is well established that these types of materials are also subjected to a size effect in dynamic response. Inversely to the known static loading size effect, the size effect in dynamic response increases with specimen size. The novel model gives excellent and acceptable results when compared with experimental and finite element ones. Size effects curves of a nominal strength of these laminates have a very close relative value with those obtained from finite element and analytical modeling. Moreover, the received design tables and graphs would be highly applicable when selecting suitable materials for similar industrial applications.

Keywords: composite laminates; infrastructure industries; natural frequency; nominal strength; size effect; strength degradation.