$20$ points $-$ Using Matlab, solve the nodal displacements, support reactions, and internal forces Material: Douglas Fir

$E=13\mathrm{.}1$GPa

$v=0\mathrm{.}29$

Member cross section:

height $=6cm$

width $=6cm$

of the $2$D truss system given above. Again, assume that the supports are one roller and one pin.

Submit the following items:

a$.$ The sketch of the truss model and the numbering of elements and nodes

b$.$ The stiffness matrix of truss element $-$ before coordinate transformation

c$.$ The element stiffness matrix after transformation $-$ for the diagonal, vertical, and

horizontal elements $($one for each element$)$

d$.$ Global stiffness matrix and reduced matrix after the application of boundary conditions

e$.$ Reduced stiffness matrix after the application of boundary conditions

f$.$ Nodal displacement solution $($node number and displacements in $x$ and $Y$ directions$).$

g$.$ Support reactions and verification using force balance law.

h$.$ List of element numbers and corresponding internal forces

i$.$ On your scripts, include comments explaining the lines