Unsymmetrical Bending of a Cantilever - Lab Report Example

The cord was placed on the groove and passed over the sliding pulley. The specimen was then rotated after undoing the top chuck. The indicators were allowed to travel 10 mm forward and 3 mm backward. The frame was tapped to reduce friction and loads applied in 100 g increments up to 500 g on the end of the cord. The resulting deflections were recorded under 'Head angle: 0°’ title. The procedure was repeated while rotating the specimen clockwise 22.5° while tightening. By using dU/dP and dV/dP as a point’s coordinate, the points therein formed the Mohr’s circle as shown in the results.

From the circle, the IX and IY were calculated for the experiment and compared to the theoretical calculation. Further, the graph of U and V (mm) against the pulling mass was used to determine the influence of the readings on the load’s eccentricity. This graph was useful in finding the position at which the readings of the two indicators were equal. From this, the shear center was established by determining the intersection point. In which case, whenever the load is placed at the intersection point (shear center), the beam does not twist, since the two indicators’ readings are equal (Ross, 2009, 198).

In order to verify the completeness of the results, hand calculations were done and then compared with the theoretical values. In which case, the distance between the shear center and line L was calculated to confirm the accuracy of the results. However, there was a difference that can be contributed to the inconsistency of the shear center beam “0” notch. This calls for the need for modifying the design of the apparatus used for this case. Even though the experiment was successful in meeting the aforementioned objectives, comparing the experimental results and theoretical calculations indicates that there is a little deviation of 2.33%. This error can be attributed to an error in measurement especially in the process of constructing Mohr’s circle.

Relatively fewer points were used, something that did not guarantee accuracy. Consequently, if more data obtained from the other head angles were used then the error could have been avoided.