Question $1$

A highway signboard $2\mathrm{.}020\mathrm{.}64$ meter is supported on a single rectangle $12080mm$ section mast as shown in figure $1.$ The sign supporting by the framework and mast at a weight of $200kg$ is located at the center of the signboard. When the signboard is subjected to the direct wind blast, the average pressure of $104$kPa is developed a force that acting at the center of the sign. You are required to design and estimate size of bolt connections and welding at the section of $A,B,C$ and $D.$ Details of these sections are shown in figure $2.$ All calculations are in SI units. Used factor of safety $2\mathrm{.}5$ for all designs.

Figure $1$: Highway SignboardDetail A and $B$ : Bolting and Welding on Base Plate

Detail C: Welding on Signboard Frame to the

mant

Figure $2$: Detail drawing for section $A,B,C$ and $D$

Answer these questions:

a$.$ Design a bolting from SAE grade $4\mathrm{.}6$ at the base plate $($Detail A$)$ and frame bracket $($Detail D$)$

b$.$ Determine the suitable size of weld size at section B and C

c$.$ Give your comments and suggestions on each results.

Note: Draw a free body diagrams for each problems and determine the magnitudes of all forces and moment reactions.