2.2 MATLAB Functions Used 19 Note that you can obtain online help from MATLAB on any of the MAT- LAB functions by using the help command.For example,to obtain help on the MATLAB function OrthotropicCompliance,use the help command as follows: >help OrthotropicCompliance OrthotropicCompliance This function returns the compliance matrix for orthotropic materials.There are nine arguments representing the nine independent material constants.The size of the compliance matrix is 6 x 6. Note that we can use the MATLAB function TransverselyIsotropicCom- pliance instead of the MATLAB function OrthotropicCompliance in this ex- ample to obtain the same results.This is because the material constants for graphite-reinforced polymer composite material are the same in the 2-and 3-directions. MATLAB Example 2.3 Repeat Example 2.2 if the cube is made of aluminum instead of graphite- reinforced polymer composite material.The material constants for aluminum are E=72.4 GPa and v=0.300.Use MATLAB. Solution This example is solved using MATLAB.First,the normal stress in the 2- direction is calculated in GPa as follows: >>s1gma2=100/(60*60) sigma2 0.0278 Next,the stress vector is setup directly as a column vector as follows: >>s1gma=[0;s1gma2;0;0;0;0] sigma 0 0.0278 0 0 0 02.2 MATLAB Functions Used 19 Note that you can obtain online help from MATLAB on any of the MAT￾LAB functions by using the help command. For example, to obtain help on the MATLAB function OrthotropicCompliance, use the help command as follows: >> help OrthotropicCompliance OrthotropicCompliance This function returns the compliance matrix for orthotropic materials. There are nine arguments representing the nine independent material constants. The size of the compliance matrix is 6 x 6. Note that we can use the MATLAB function TransverselyIsotropicCom￾pliance instead of the MATLAB function OrthotropicCompliance in this ex￾ample to obtain the same results. This is because the material constants for graphite-reinforced polymer composite material are the same in the 2- and 3-directions. MATLAB Example 2.3 Repeat Example 2.2 if the cube is made of aluminum instead of graphite￾reinforced polymer composite material. The material constants for aluminum are E = 72.4 GPa and ν = 0.300. Use MATLAB. Solution This example is solved using MATLAB. First, the normal stress in the 2- direction is calculated in GPa as follows: >> sigma2 = 100/(60*60) sigma2 = 0.0278 Next, the stress vector is setup directly as a column vector as follows: >> sigma = [0 ; sigma2 ; 0 ; 0 ; 0 ; 0] sigma = 0 0.0278 0 0 0 0