Torsion Testing
Table of Contents Abstract 3 1.0 Introduction 3 2.0 Experiment Design 4 2.1 Apparatus 5 2.2 Methods 5 2.3 Procedure 6 3.0 Results and Discussion 7 4.0 Error Analysis 13 5.0 Conclusion and Recommendation 13 6.0 References 14
Abstract
In this torsion testing experiment, the torsion test was evaluated as a system for calculating the torsional rigidity (GJ), modulus of rigidity (G) and the shear yield stress (τ) for aluminium, mild steel and brass. The both ends of the cylindrical specimen are tightened to hexagonal sockets, which one is fixed to a torque shaft and another is fixed to an input shaft. By turning the input handwheel, the twisting moment has applied to produce the torque until the specimen fails. In the end of the experiment, it shows that the comparison of the behaviour of ductile and brittle materials under torsion.
1.0 Introduction
The responses of metals were deal by mechanical testing to applied forces. This testing includes torsion, tension, hardness, fatigue, creep and stress rupture, and impact tests. Torsion occurs when any shaft is subjected to a torque. The torque causes the shaft to twist. This makes one of the ends to rotate relative to the other; shear stress is induced on any cross section. Besides that, torsion testing is made on materials to determine modulus of elasticity in shear, torsion yield strength and the modulus of ruptures.
The shearing stress at any point on a transverse cross section varies directly proportional as the distance from the centre of the shaft, when a simple circular solid shaft is twisted. Therefore, during twisting, the cross section is initially planar remains a plane and rotates only about the axis of the shaft.
2.0 Experiment Design
Figure 7: 360 degree protractor scale
Figure 6: Three specimen mild steel (top), brass (middle), and aluminium (bottom) after experiment.
Figure 5: Three specimen mild steel (top), brass (middle), and aluminium (bottom) before experiment. Figure 2: Torque meter
Abstract
In this torsion testing experiment, the torsion test was evaluated as a system for calculating the torsional rigidity (GJ), modulus of rigidity (G) and the shear yield stress (τ) for aluminium, mild steel and brass. The both ends of the cylindrical specimen are tightened to hexagonal sockets, which one is fixed to a torque shaft and another is fixed to an input shaft. By turning the input handwheel, the twisting moment has applied to produce the torque until the specimen fails. In the end of the experiment, it shows that the comparison of the behaviour of ductile and brittle materials under torsion.
1.0 Introduction
The responses of metals were deal by mechanical testing to applied forces. This testing includes torsion, tension, hardness, fatigue, creep and stress rupture, and impact tests. Torsion occurs when any shaft is subjected to a torque. The torque causes the shaft to twist. This makes one of the ends to rotate relative to the other; shear stress is induced on any cross section. Besides that, torsion testing is made on materials to determine modulus of elasticity in shear, torsion yield strength and the modulus of ruptures.
The shearing stress at any point on a transverse cross section varies directly proportional as the distance from the centre of the shaft, when a simple circular solid shaft is twisted. Therefore, during twisting, the cross section is initially planar remains a plane and rotates only about the axis of the shaft.
2.0 Experiment Design
Figure 7: 360 degree protractor scale
Figure 6: Three specimen mild steel (top), brass (middle), and aluminium (bottom) after experiment.
Figure 5: Three specimen mild steel (top), brass (middle), and aluminium (bottom) before experiment. Figure 2: Torque meter
References: 1) “Laboratory Handbook”, Taylor’s University, 2012/2013. 2) J.L.Meriam and L.G.Kraige, 2006, Engineering Mechanics Statics. 6th Ed. 3) http://www.scribd.com/doc/136565/Mechanics-of-Materials-Torsion-Test 4) http://www.ce.siue.edu/330L/Lab%20Help%20Desk/Metal%20Torsion%20Test/Metal%20Torsion.pdf 5) http://www.scribd.com/doc/50848950/4/TORSION-TEST-ON-MILD-STEEL-ROD 6) http://eng.sut.ac.th/metal/images/stories/pdf/Lab_4Torsion_Eng.pdf 7) http://encyclopedia2.thefreedictionary.com/torsional+rigidity