23-11-2012, 12:11 PM
FINITE ELEMENT ANALYSYS OF COMPOSITE CYLINDER
FINITE ELEMENT ANALYSYS.ppt (Size: 991.5 KB / Downloads: 45)
Composites
Composite Materials:
They can be defined as a material with two (or more) distinct macroscopical phases. They consist of two or more materials combined in such a way that the individual materials are easily distinguishable. A common example of a composite is a concrete.
Types of Composite fabrication:
Wet Lay-up/Hand Lay-up
Filament Winding
Pultrusion
Resin Film Infusion (RFI)
Spray Lay-up
Resin Transfer Moulding (RTM)
Hand Lay-up
Resins are impregnated by hand into fibres which are in the form of woven, knitted, stitched or bonded fabrics. This is usually accomplished by rollers or brushes, with an increasing use of nip-roller type impregnators for forcing resin into the fabrics by means of rotating rollers and a bath of resin. Laminates are left to cure under standard atmospheric conditions.
Vacuum Bagging for Hand Lay-up
This is basically an extension of the wet lay-up process described above where pressure is applied to the laminate once laid-up in order to improve its consolidation. This is achieved by sealing a plastic film over the wet laid-up laminate and onto the tool. The air under the bag is extracted by a vacuum pump and thus up to one atmosphere of pressure can be applied to the laminate to consolidate it.
Filament Winding
This process is primarily used for hollow, generally circular or oval sectioned components, such as pipes and tanks. Fibre tows are passed through a resin bath before being wound onto a mandrel in a variety of orientations, controlled by the fibre feeding mechanism, and rate of rotation of the mandrel.
Pultrusion
Fibres are pulled from a creel through a resin bath and then on through a heated die. The die completes the impregnation of the fibre, controls the resin content and cures the material into its final shape as it passes through the die. This cured profile is then automatically cut to length.
Advantages of Composites
Density of aluminum alloy approximately 2800 kg/m3
Density of carbon/epoxy approximately 1580 kg/m3
Tensile strength of aluminum alloy 7075-T6 is 570 MPa
Tensile strength of carbon/epoxy 1830 MPa
INTRODUCTION TO ANSYS
This will use a readymade file to speed up the learning process for the student. This file is provided in Para-solid format. The intention of this is to get the student to run a straight forward simulation. ANSYS as a software is made to be user-friendly and simplified as much as possible with lots of interface options to keep the user as much as possible from the hectic side of programming and debugging process.
The objective of this is that the student masters the steps to get run a simple simulation. once that’s done the student can model any kind of geometry he sees necessary for his studied case.
Advantages of ANSYS
Changing material properties or layer orientation is simple.
Many different orientations can be analyzed in a short amount of time.
ANSYS can predict results before fabricating composite sample.
Complex geometries can be modeled and evaluated easily.