Analysis of the properties of honeycomb composite panels

By

ACKNOWLEDGEMENTS

My thanks go out to all who have helped me complete this study and with whom this project may have not been possible. In particular, my gratitude goes out to friends, facilitator and family for extensive and helpful comments on early drafts. I am also deeply indebted to the authors who have shared my interest and preceded me. Their works provided me with a host of information to learn from and build upon, also served as examples to emulate.

.

DECLARATION

I, (Your name), would like to declare that all contents included in this thesis/dissertation stand for my individual work without any aid, & this thesis/dissertation has not been submitted for any examination at academic as well as professional level previously. It is also representing my very own views & not essentially which are associated with university.

Signature:

Date:

TABLE OF CONTENTS

ACKNOWLEDGEMENTSII

DECLARATIONIII

CHAPTER 2: LITERATURE REVIEW1

Mechanical Properties of Honeycomb panels1

Finite Element software ANSYS1

Properties of Honeycomb Panels2

Continuum Assumption in Vibration Analysis of Honeycomb Panels3

Prediction of Mechanical Properties of Honeycomb Structures5

Aluminum honeycomb6

Energy absorber7

Crush behaviour10

Thermal behaviour11

REFERENCES13

CHAPTER 2: LITERATURE REVIEW

Mechanical Properties of Honeycomb panels

Two aluminium honeycomb panels were used as specimens in this thesis. The face sheets along with the honeycomb panels are all made of 5052 aluminium alloys. The mechanical properties of the honeycomb panels of the two specimens were determined by the formulae given by Gibson and Ashby (Mohr 2008, 2262). The measured densities of the honeycomb panels are higher than the formula-determined densities because the formula given by Gibson and Ashby did not include the mass of the glue used to attach the walls of the core and the core to face sheets. However, because the density of a honeycomb core is extremely low, the effect of glue (about 20%) is quite significant. Fortunately, unlike other material properties, the density of a honeycomb core can be easily measured and is usually provided by the manufacturers. In this thesis, the actual densities provided by the manufacturer are used (Lin 2004, 147).

Finite Element software ANSYS

Most sandwich panels are symmetrical with respect to the mid planes in the thickness direction. The symmetrical structures are easy to be handled and manufactured. The most important reason to use honeycomb panels is for reducing weight. In order to reduce more weights, the thickness of two face sheets of a honeycomb panel may be different (Goldsmith 2008, 1017). The face sheet of a panel that resists loads is thicker than the face sheet on the other side. This design can reduce the extra material of honeycomb panels. Therefore, honeycomb panels used in industry may be unsymmetrical (Doyoyo 2009, 1195).

The analysis of deformations of an unsymmetrical honeycomb panel is very complicated. It is difficult to obtain an analytical solution for free flexural vibration of a honeycomb panel with arbitrary boundary conditions. In this thesis, a commercial FE software package ANSYS is employed to seek an approximate numerical solution. There are two types of elements provided by ANSYS for modeling a layered panel (Harrigan ...