Task $1$: Deflections of Pin$-$jointed Structures and Beams

Objective:

To experimentally determine the deflection of a loaded pin$-$jointed structure and

compare it with the theoretical deflection calculated using virtual work analysis.

To theoretically compare deflections of simply supported and cantilever beams

using virtual work analysis.

Part $1$: Experimental Task:

Plane trusses in their various forms constitute one of the most widely used structural

components. They are used in bridges and roof support structures and form a vital part

of most cranes. This experiment acts as an introduction to the deflection design of

plane trusses.

The deflection of any joint of a truss can be found by using the "Unit Load Method"

which is based on the Principle of Virtual Work, as explored in the lecture programme.

For the truss shown below, the deflection of joint $G$ is determined experimentally and

calculated theoretically to enable comparison between the structural model and an

idealised pin$-$ jointed structure.The cross$-$sectional areas of tension members and compression members of the truss are to be selected as $1000$ mm$2$ and $1250$ mm$2$ respectively. The modulus of elasticity of steel is to be taken as $205$ kN$/$mm$2.$ The yield strength of steel can be taken as $250$ N$/$mm$2.$ if W $=100$ KN$,$ what would the deflection at G be$?$ if the distance between any two joints is $2\mathrm{.}2?$