Mechanics of Aircraft structures
C.T. Sun
8.4 If the carbon/epoxy composite panel is subjected to a shear stress xy , find
(a) the fiber orientation at which 11 is maximum.
(b) the fiber orientation at which xy is minimum.
Compare the result with that of

Mechanics of Aircraft structures
C.T. Sun
8.2
Consider a rectangular composite panel with = 45 o (material properties are
given in Problem 8.1) subjected to xx = 10 MPa , yy = 0 , xy = . Find
that is necessary to keep the deformed shape rectangular.
Solu

Mechanics of Aircraft structures
C.T. Sun
8.1
Given a carbon/epoxy composite panel under uniaxial loading, i.e., xx = 0 ,
yy = xy = 0 , plot xy as a function of the fiber orientation . The composite
properties are
E1 = 140GPa ,
E 2 = 10GPa ,
G12 = 7GPa ,

Mechanics of Aircraft structures
C.T. Sun
8.6
Compare the in-plane longitudinal stiffnesses in the x-direction for [ 30 / 0]s
and [30 2 / 0]s laminates of AS4/3501-6 carbon/epoxy composite. Which is
stiffer?
Solution:
The effective engineering moduli in t

Example 2
Saturday, October 10, 2015
8:12 AM
Calculate the laminar stresses in a Quasi-isotropic Symmetric Laminate [+-45/0/90]s under a
Uniaxial load N.
Composites Page 1
Composites Page 2
Composites Page 3
Composites Page 4

Mechanics of Aircraft structures
C.T. Sun
8.5
Consider a [ 45]s laminate. If the constituent composite material is highly
anisotropic, i.e.,
E1 > E 2 and E1 > G12
show that the effective engineering moduli for the laminate can be expressed
approximately a

Mechanics of Aircraft structures
C.T. Sun
8.3
Plot the extension-shear coupling coefficients x, xy and xy , x versus for
the composite given in Problem 8.1. Find the s that correspond to the
maximum values of x, xy and xy , x , respectively.
Solution:
The

Mechanics of Aircraft structures
C.T. Sun
8.8
Find the shear strains ( xy ) in the AS4/3501-6 carbon/epoxy composite [ 45]s
and [0 / 90]s laminates subjected to the shear loading N xy = 1000 N / m . Also
find the lamina stresses 11 , 22 , and 12 . If the

Mechanics of Aircraft structures
C.T. Sun
8.7
Plot the effective moduli E x , G xy , and xy versus for the angle-ply
laminate [ ]s of AS4/3501-6 carbon/epoxy composite.
Solution:
The effective engineering moduli for the symmetric laminate are
A A A12
E x

Aerospace Structures (ME 6300) Homework 1
Due: August 29th, In Class
Instructor: Dr. Sushma Santapuri
Reading Assignment Problem 1: List the basic components of an aircraft (you can refer to the
material posted on blackboard).
Discuss the design and funct