The document provides MATLAB code to calculate various properties of a composite material given fiber and matrix properties like modulus, Poisson's ratio, volume fraction, and thermal expansion coefficients. The code prompts the user to input these properties and calculates the composite's modulus, shear modulus, Poisson's ratio, and coefficients of thermal expansion. Results are presented for a problem where the fiber modulus is 230 GPa, matrix modulus is 3.4 GPa, and fiber volume fraction is 0.55.

1. Solution
Solution
Use table 2.4 for matrices properties and table 2.1 for fibers properties.
a)

2. ---------------------------------------------------------------------------
b)
------------------------------------------------------------------
c)

3. I have tried a lot of combinations and volume fraction using data from tables
mentioned above and I couldn't choose materials that satisfy the requirements.
To be asked about in the lecture.
MATLAB Code
clear;clc;close all;
Ef=input('Ef(in GPa) = ')
Em=input('Em(in Gpa) = ')
nu_f=input('fiber poisson ratio = ')
nu_m=input('matrix poisson ratio = ')
Vf=input('fiber volume fraction = ')
alfa_f=input('fiber thermal expansion coeff = ')
alfa_m=input('matrithermal expansion coeff = ')
Vm=1-Vf;
Gf=Ef/(2*(1+nu_f))
Gm=Em/(2*(1+nu_m))
E1=Vm*Em+Vf*Ef
E2=Ef*Em/(Vf*Em+Vm*Ef)
G12=Gf*Gm/(Vf*Gm+Vm*Gf)
eta23=(3-4*nu_m+Gm/Gf)/(4*(1-nu_m))
G23=Gm*((Vf+eta23*(1-Vf))/(eta23*(1-Vf)+Vf*Gm/Gf))
nu_12=nu_f*Vf+nu_m*Vm
alfa1=alfa_f*Vf*Ef/(Vf*Ef+Vm*Em)+alfa_m*Vm*Em/(Vf*Ef+Vm*Em)
alfa_2=alfa_f*Vf+alfa_m*Vm
Results On problem 4.6 part (C)
Ef(in GPa) = 230

4. Ef =
230
Em(in Gpa) = 3.4
Em =
3.4000
fiber poisson ratio = 0.2
nu_f =
0.2000
matrix poisson ratio = 0.38
nu_m =
0.3800
fiber volume fraction = 0.55
Vf =
0.5500

5. fiber thermal expansion coeff = 0
alfa_f =
0
matrithermal expansion coeff = 0
alfa_m =
0
Gf =
95.8333
Gm =
1.2319
E1 =
128.0300

6. E2 =
7.4215
G12 =
2.6952
eta23 =
0.6020
G23 =
3.6382
nu_12 =
0.2810
alfa1 =

7. 0
alfa_2 =
0