Design and Analysis of a Laminated Composite Tube

COMPOSITES COURSEWORK

DESIGN AND ANALYSIS OF A LAMINATED COMPOSITE TUBE

ABSTRACT

This report details the process for the design of a composite laminate tube, the software package 'MathCAD' was used to determine a lamina design with a configuration that avoids mechanical failure under loading conditions. It was also used to obtain twist angles and maximum stresses for specific lamina wind up angles. The report will provide analysis of the methods used to obtain these criteria.

AIM

Use a Mathcad script to determine the procedure used during the manufacture of a wound laminate composite tube and to assess its validity for use in stress and strain analyses.

INTRODUCTION

FIGURE 1 A DEVELOPED VIEW OF A TAPE-WOUND CYLINDRICAL TUBE

The laminates of the composite tube adopted a [α/β/α/β] layup with a winding angle range between [-75, -45] or [+45, +75], these tapes were cut from a UD pre-peg sheet onto a 50mm mandrel. Tape widths were dependant on the winding angles in order to avoid gaps or overlaps as a result of winding onto the mandrel; this would affect the part performance or decrease material efficiency respectively.

The thickness of the pre-peg sheet is 0.25mm and the finished tube should be at a length of 300mm.

MATERIAL

Material properties of the carbon-epoxy (SE 84LV/HSC/300g/400mm/37%/1 blue) used to constrict the composite where as follows:

E1

(GPa)

E2

(GPa)

G12 (GPa)

ν12

σ*1t (MPa)

σ*1c (MPa)

σ*2t (MPa)

σ*2c (MPa)

τ*12 (MPa)

236

5

2.6

0.25

3800

689

41

117

69

TABLE 1 CARBON-EPOXY PREPREG PROPERTIES

A composite material is a material made from two or more constituents with significantly different physical or chemical properties. There are two main categories of constituent materials, matrix and reinforcement. At least one material of each type is required. (Composite Material).

The phase distribution and geometry of the two materials have been ordered to optimise its properties, this has led to the increased

Bibliography: _Composite Material_. (n.d.). Retrieved 03 19, 2013, from Wikipedia: http://en.wikipedia.org/wiki/Composite_material _Material failure theory_. (n.d.). Retrieved 03 19, 2013, from Wikipedia: http://en.wikipedia.org/wiki/Material_failure_theory Figure � SEQ Figure * ARABIC �3� Laminate coordinate system Figure � SEQ Figure * ARABIC �5� Cross sectional view of a laminate Figure � SEQ Figure * ARABIC �6� Axial load demonstrating stress in x direction Figure � SEQ Figure * ARABIC �8� Twist angle diagram Figure 9� SEQ Figure * ARABIC � Cylinder Twist Angle for +- 90o Figure 10 Maximum angle of twist consideration area