D28MA Civil Engineering Material

The load applied to the beam is then to be recorded against the displacement obtained fromthe central dial gauge as shown above. The results of the test can then be used to determinethe beam’s flexural Young’s Modulus.The Technicianwill now go through the procedure with you inmore detail. The following sheets of this handout must be used to provide a report on theexperiment. You must answer the questions given in Bold.1) Draw the beam’s cross-section below and, without disturbing the beam, measure thedimensions and thickness of the specimen2) What is the distance of the neutral axis from the beam’s upper surface?3) Determine the 2nd moment of area of the cross-section along the beam’s neutral axis

Now ensure that the dial gauge spindle is in contact with flatsurface and thatthe needle is set to zero.4) Carefully add weights to the beam at the places indicated on the beams uppersurface. After each incrementrecord the number indicated on the dial gauge and convert to displacement asappropriate in Table 1.Table 1: Experimental Data Steel Increment NumberWeight Added Per Position (N)Displacement (mm)Table 2: Experimental Data Brass Increment NumberWeight Added Per Position (N)Displacement (mm)Table 3: Experimental Data AluminiumIncrement NumberWeight Added Per Position (N)Displacement (mm)5) On a separate piece of paper plot a graph of load versus deflection for all the materials in the same graph and attach it tothis report. What does the graph tell you about the behaviour of the beam overthe loadrange applied?6) Using structural mechanics determine the peak bending moment applied to the beamat a load of 100N per location (ignore the weight of the beam itself). Hint first draw thebeam arrangement:7) Using the following 1-point beam bending equation estimate the flexural stiffness(Young’s Modulus) of the beam at the load given in (6) above (i.e. at the appropriatedisplacement):