2:09 PM G 42.9 + '&AC 1 2 3 5 6 24 UNIVERSITY OF ABUJA FACULTY OF ENGINEERING DEPARTMENT OF MECHANICAL ENGINEERING COURSE: STRENGTH OF MATERIALS TOPIC: TORSION APPARATUS LABORATORY PRACTICAL 1 form the res OBJECTIVE: To observe the relationship between torque and angular deflection of a specimen subject to torsional loading and to determine the modulus of the rigidity of the shaft material. sses in d the ir resul APPARATUS: Torsion Apparatus m in ( acceler id its btaine THEORY: The following assumptions are made when considering the shaft subject to pure torque as shown. id saf R Shear Strain EXPERIMENTAL PROCEDURE: Set up the as described and position the deflection gauge at about three quarters of the length of the specimen, measured from the fixed end. Accurately measure the distance L. before applying any load. Apply a load of (say) 0.2kg to the load hanger and record the deflection obtained. Increase the load by increments of 0.2kg up to the maximum available (depending on the strength of the shaft) each time total value of 0. Tabulate the results as below. Effective length of shaft L-m recording ||| = O כ Մ ccel ating orqu Nm form M 2:09 PM G + '%AC K/S EXPERIMENTAL PROCEDURE: Set up the as described and position the deflection gauge at about three quarters of the length of the specimen, measured from the fixed end. Accurately measure the distance L before applying any load. Apply a load of (say) 0.2kg to the load hanger and record the deflection obtained. Increase the load by increments of 0.2kg up to the maximum available (depending on the strength of the shaft) each time recording total value of 0. Tabulate the results as below. Effective length of shaft L-m M form e. the n Diameter of shaft D-m Radius of torsion pulley a-m sses i d the Load Mass M Kg Torque T-Mga Angular Deflection 0 Nm rad RESULTS: Plot a graph of torque T vertically against angular deflection 0 The graph should be a straight line of slope GJ Where J- 32 accele id its btain id sa ccele ating Measure the slope of the straight part of the graph ignoring any initial vibrations. Hence determine the value of G. G = (slope) x Compare the value obtained for G with typical values for the material obtained from data books or other reference works. Comment on any discrepancy, suggesting reasons for its origin. Comment also on the shape of the graph and the information it provides on torsion theory. orqu Nm = ||| о U 7 Mo t In