c$.$ Size all the bars in the truss BCDF using Standard weight pipes made of A$36$ steel.

d$.$ Size the two columns $($AB and DE$)$ using wide flange W$8,$ A$36$ steel profiles

e$.$ Sketch the truss and show, on all bars: $(1)$

the axial forces that you calculated at $($a$)$

use red for compression and blue for

tension, and $(2)$ the type of sections you

determined at $($c$)$ and $($d$).$

Use a factor of safety for buckling, $$b $=2.$ Use

Table $5\mathrm{.}2$ in Handout $6$ for material properties and

Tables A$3$ and A$5$ in OK$-$Appendix for steel profile

geometry. Neglect the self$-$weight of the bars and

columns.

Problem $2.$ All members of the Howe truss discussed in Homework $4$ Problem $2$ are made of Doug Fir wood

with $6$x$10$ nominal sections. You are required to check if the selected member section is safe for the

loading shown in that problem. Check for the maximum forces in top and bottom chords and in braces that

you calculated in Problem $2,$ HW$4.$ For members in compression look at both crushing resistance and

buckling resistance.

See Table $5\mathrm{.}2$ in Handout $6$ posted on Canvas under $$Triangulated Structures$$ for modulus of elasticity, E$,$

allowable tension stress, F t$,$ and allowable compression stress, F c $.$ Use the values listed for Beams and Posts.

These allowable stresses $($denoted by F a in the lecture$)$ already include a factor of safety, namely F t $=$ Fy$/$

and F c $=$ Fyc $/.$ Use a factor of safety $$b $=2$ only for buckling analysis.

The actual dimensions and sectional properties for lumber are listed on the last page of Handout $3$ posted

on Canvas under $$Loads and Load Flow$.$

Hint: When you check for buckling for a rectangular cross$-$section, use the smaller moment of inertia $($I yy in

Handout $3).$c$.$ Size all the bars in the truss BCDF using Standard weight pipes made of A$36$ steel.

d$.$ Size the two columns $($AB and DE$)$ using wide flange W$8,$ A$36$ steel profiles

e$.$ Sketch the truss and show, on all bars: $(1)$ the axial forces that you calculated at $($a$)$ use red for compression and blue for tension, and $(2)$ the type of sections you determined at $($c$)$ and $($d$).$

Use a factor of safety for buckling, ${}_b=2.$ Use Table $5\mathrm{.}2$ in Handout $6$ for material properties and Tables A$3$ and A$5$ in OK$-$Appendix for steel profile geometry. Neglect the self$-$weight of the bars and columns.