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1.2 in market of engineering applications, the

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1.2       Problem statement

 

            Recently, sandwich composite
structures are widely used in aerospace, marine and automative applications.
The significant of using honeycomb sandwich panels because their highly
efficient in stiffness-to-weight situations, strength-to-weight-ratios and
energy absorptions capabillties (J.R Vinson 1999). As an increasing the demand
in market of engineering applications, the implementation of additive
manufacturing (AM) in fabrication sandwich composite is significant due to the
low cost in manufacturing, easy to shape any profile shape, flexibility in
manufacture and fast fabrication part in manufacture.

 

            For cost in manufacturing, using
subtactive method can exposed a lot of material that need to be removed and
mostly this material cannot be recycled. Waste material occured when cores are
machined from large and flat sheet. From this factor, it can exposed to the
high cost of sandwich panel. This is proven when the component of wing mass is
estimated about 30% and 70% comes from the cost (Pollard
et al. 2017). In aerospace
fields,the components often have complex geometries because aerospace
applications usually require components with integrated functions. A large
volume envelope-to-volume ratio, as in thin-walled structures, combustion
chambers or turbine blade  the tool path
planning algorithm very complicated, time consuming, and material-consuming by
conventional computer numerical control (CNC) machining. By implementation of
AM, capability for freeform fabrication makes it very suitable for these kind
of aerospace components.

 

            Traditional core
materials like foam and Nomex honeycomb are milled using a tool path program
and CNC equipment to sculpt the desired shape take 18 days and $27,000 to build
a first article using traditional methods. Using FDM, it can produce a first
article in roughly 6 days and at a cost of about $13,000.

 

 (Jolie et al.,2017) evidence
exists in the aerospace industry which has reported a 70–85% reduction in man
hours due to the implementation of automated composite tape layers wings and
other internal features without degrading the composite core’s structural
integrity. Producing these features with conventional core materials and
fabrication methods is difficult or impossible due to the complex geometries
involved. The wind turbine blades will employ a sandwich structure instead of
the more traditional skin-over-rib design used by most turbine blade
manufacturers. Using FDM and a high modulus material like Polycarbonate, net
shaped cores can be fabricated with the shear and compression strength needed
to withstand the temperatures and pressures

 

             In fabrication sandwich structure the common
failure mode in sandwich composite structure which is compression are
investigate.To test behavior of compression sandwich composite structure, there
are two types of test need to carried out such as flatwise and in-panel

compression test. This test will be conducted using ASTM C365 M-05 and ASTM C364-16.

 

 

1.3       Objectives

 

To investigate the relation 3D printed honeycomb sandwich composite
structure   materials against compression
behaviour of sandwich composite structure.

     

1.3.1       
To
investigate the varying thickness of hexagonal honeycomb core using flatwise
compression test with ASTM C365 M-05

 

1.3.2       
To
investigate the varying thickness of hexagonal honeycomb core using in-panel
compression test with ASTM C364-16 respectively.

 

 

1.4       Scopes of research

 

            This study review the effect of
compression behaviour of sandwich composite structure subjected to flatwise
compression and inplane compression loading. The hexagonal honeycomb core are
designed using 3D CAD software then fabricated with additive manufacturing
technique.  Fused deposition modeling, FDM-01
(Mankati Fullscale XT Plus)  are used in fabrication core structure. The type
of material used for this machine is polylactic acid (PLA) while sandwich
composite structure with honeycomb core were manufactured by using ply flax
fiber for the facesheet. Types of flax fiber used in this fabrication is (2´2
twill)  in 400g/m2. Adhesive material used to honeycomb core are

epoxy resin and
vacuum bagging process. Flatwise and inplane compressive test were investigated
to evaluate the compression behaviour of sandwich structure with ASTM C365 M-05
and ASTM C364-16. The various of failure modes were discussed based on the test
results.

 

 

1.5       Organization of report

 

This study is
organized into the following chapters:

Chapter 1:
Introduction

            Explain about the introduction of
the present work. This chapter will be divided into several subtopics of
research backgrounds, problem statement, objectives, scopes and organization of
report.

 

Chapter 2:
Literature review

            Literature review on the current
fabrication sandwich composite structure and methods along with an overview of
the previous process. This chapter also exposed to the compression test for
sandwich composite structure and their finding during the experiment. The
overall thesis organization for manufactured sandwich composite stucture using
additive manufacturing, FDM, and investigation on compression behavior within varying
thickness.

 

Chapter 3:
Methodology

            Provides the details about the
material that were used and geometries properties of the honeycomb core, face
sheets . Compression test, flatwise and in plane compression test were
performed to investigate the compression behaviour between sandwich strcture
design parameters.

 

Chapter 4:
Result

            Explain the result and discussion.
The result ontained throughout the experiment will be compared with the
findings o present research and result will be discuss throughly.

 

Chapter 5:
Conclusion Work

            The conlcusions of this research
work are discussed along with the recommendations for future work.