Structural description: Many structures can be modeled and analyzed as a simple truss

structure. As you recall from your Statics course, a truss is a structure of slender members joined

together at their pinned endpoints. When designing the members and joints of a truss, first, it is

necessary to determine the forces in each truss member, and when doing this, two assumptions

are made:

All loads are applied at the joints. The weight of the truss members is often neglected.

Smooth pins join the members together. This assumption is satisfied in most practical cases

where the joints are formed by bolting the ends together.

With these two assumptions, the truss members act as two$-$force members. They are loaded in

either tension or compression. Often, compressive members may need to have thicker cross$-$

sections to prevent buckling. For this project, you will design and analyze a two$-$dimensional

truss structure to determine an "optimal" truss layout and "optimal" cross$-$sectional

geometry for each truss member to carry several point loads.

Design Requirements: You are required to design a $2$D truss that spans over a horizontal length

of $20ft.$ Design requirements are as follows:

You need to select the height and configuration of the truss.

The truss must be designed to support a concentrated load of $15,000lbs$ at its center and

two other concentrated loads, one of $10,000lbs.$ four fret from one end and another of

$5,000lbs.$ four feet from the other end.

A minimum safety factor is $1\mathrm{.}5$ for all members under all possible failure mechanisms

$($yielding and buckling$)$

The truss must be adequately supported at its ends.

The cross$-$section of each truss member must be sized appropriately to ensure each one

will be safe against yielding and$/$or buckling.

All truss members must have circular cross$-$sections with dimensions in increments of $\frac{1}{8}$

in$.$

The thickness$-$to$-$diameter ratio must be no smaller than $\frac{1}{16}$ if using tubular cross$-$

sections.

All truss members must be made of A$-36$ steel.

You may neglect the weight of the truss members when designing them.

After selecting the cross$-$sectional dimensions for all members, you need to check the

truss's total weight and assess it against the prescribed loading conditions.

Basis for grade: Your team's grade will be based on the accuracy and detail of your analysis and

the total weight of the structure. The goal is to minimize structural weight while meeting all

other design requirements.