512 Words3 Pages

DISCUSSION
From the book Mechanics of Materials,3rd Edition by R. C. Hibbeler, Ferdinand P. Beer, E. Russell Johnston Jr. and John T. DeWolf, the value for modulus of rigidity, G of mild steel is 80GPa. The authors also wrote that the value of G is not less than one third and not more than half of modulus of elasticity, E. which E for mild steel is 210GPa. The value of G, for this experiment can be obtained from the slope of the graph shear strees against shear strain. By using simple calculation, the value of G is 54.27 GPa. The differences experimental value and theoretical value is around 32.16%, which the experimental value is smaller than theoretical value. Those value were difference because we are using a manual torsion tester with raising the revolution twist by staged. After one revolution and after the meter tester were stop the reading will be taken, and so on until the specimen fractured. So the graph of this experiment not exactly obeyed Hooke’s Law. We can obey the Hooke’s Law if we are using the automatic torsion tester with smooth load will be apply to the specimen, and much more accurate. We also can get the exact fracture load of the specimen. The graph torque, T against angle θ for the first five reading are plotted obeyed the Hooke’ Law, those graph seem almost a linear line.
For the torsion test experiment, there will be 2 type fracture surface; a) Cup-and-cone fracture. b) Brittle fracture. (ductile fracture)
i. The ductile fracture may have a gray, fibrous appearance. ii. Ductile fractures are associated with overload of the structure or large discontinuities. The brittle fracture are associated with a smooth and constant load continuities.
So our specimen were had a ductile fracture surface, with having a bit necking and cup-and-cone surface. Figure

Related

## Calculating Deflection of a Statically Indeterminate Beam Under Loading

3332 Words | 14 PagesStrengths Lab report Calculating deflection of a statically indeterminate Beam under loading Summary The purpose of this experiment was to investigate the accuracy of theoretical calculation for deflection in beams compared to that of experimental procedure. Our findings showed us that theoretical calculations are an accurate method of approximation and also that deflection directly varies with transverse force applied. Therefore the use of theoretical calculations for engineering design is an accurate and useful and time saving method. We also used load cells to calculate reaction forces and moments. For the calculation of the reaction moment at the support mounted on an arm, the value for the reaction force is multiplied by the distance at which the force is acting.

## Hydraulics - Flow in Rough & Smooth Pipes

410 Words | 2 PagesAll pipes, whether they be concrete, clay, PVC or other have a relative roughness at a microscopic level which contributes to frictional losses in the pipeline. It is important to calculate the frictional losses so adjustments can be made to the operating pressures to counteract the losses which are experienced over long distances. The calculations help better plot the actual velocities flowing within pipe networks so more accurate pipe size & gradients can be selected in practice. The main aim of this experiment was to investigate frictional head losses in rough and smooth pipes of varying diameter with varying velocities in order to analyse and discuss the finding of the experiment. Theoretical predictions were made for head loss (hf) and compared to actual ‘measured’ values obtained during the experiment.

## Torsion of Circular Shaft

386 Words | 2 PagesDetermine the required diameters of the steel shafts on the pulleys at A and B if the allowable shear stress is tallow = 85 MPa. Figure 4 5. The solid steel shaft DF has a diameter of 25 mm and is supported by smooth bearings at D and E. It is coupled to a motor at F, which delivers 12 kW of power to the shaft while it is turning at 50 rev/s. If gears A, B, and C remove 3 kW, 4 kW, and 5 kW respectively, determine the maximum shear stress developed in the shaft within regions CF and BC. The shaft is free to turn in its support bearings D and E. Figure 5 6.

## Rotational Equillibrium Essay

410 Words | 2 PagesMaking the left side our positive direction, and our right, the negative direction was essential in proving algebraically, the results of the experiment. When we say, “balance,” we mean to say we will try to set the net torque equal to zero, Σ Ʈ=0, we want all the forces on opposite sides to cancel out, giving us an even leveled meter stick. In our experiment, we had two different parts, each containing three slightly different trials. In the first half of the experiment, we hung the meter stick on the 50.0 cm mark and placed different weights on different ends. We moved around the weights until we ended up with what we saw to be an even leveled meter.

## Mass, Volume And Density

1696 Words | 7 PagesThe purpose of this experiment is to understand the uses and functions of various devices used to receive the most common units of measurement in physics for mass, volume and density. We were given a steel ball, a rectangular aluminum block, a brass cylinder and an aluminum annular cylinder to be measured by a vernier caliper, micrometer and weight balance. We learned the uses of the equipment and the values given through measure to obtain the significant figures needed for accuracy. In this experiment, we will take the average of 5 measurements to produce a value of great accuracy in which we will use for our final answer. We will then compare it with the given value provided in our Physics Lab’s manual.

## Absract on "The Phenomena of Rupture and Flow in Solids"

502 Words | 3 PagesAbstract on A.A Griffith, “The Phenomena of Rupture and Flow in Solids”, Retrospective Fracture Mechanics, Vol. CCXXI- A 587, October 21, 1920. This paper deals with the understanding of the formation and spreading of cracks or flaws in a material and their effect on its strength. The author looks into the intermolecular cohesion for an explanation for this behavior. The previous explanations on the effect of cracks in bodies stated that the maximum stress and strain in a body with cracks is 2 to 6 times higher than one without cracks, depending on their shape and nature of applied stress and independent of absolute size of the crack.

## Strain Hardening Essay

1201 Words | 5 PagesMechanical properties such as the proportional limit, the ultimate strength, and the modulus of elasticity are determined for each specimen and compared. BACKGROUND: Strain hardening, work hardening, and cold working all refer to the increase in deformation resistance obtainable by loading ductile metals. A stress versus strain diagram from a strain hardened tensile specimen is shown in Figure 1. The specimen was loaded in tension beyond the proportional limit (A) to point B. The load is then removed from the specimen; the unloading curve B-C being nearly parallel to the initial portion of the stress-strain curve.

## Dicussion About Experiment in Resonance Tube

636 Words | 3 PagesThere are some losses from cycle to cycle, this phenomenon is called DAMPING. When it is at small scale, it's frequency can achieve almost equal as the natural frequency of the system which is frequency of unforced vibrations. Almost every sytems have multiple and different resonant frequencies. -In this experiment we found ourselves caught in several errors. During the experiment, instead of using tools or apparatus, we used our own hearing to determine the resonance by listening the volume of the produced amplitude, thus causing inaccuracy in recording results.

## Elementary Vibrations Experiment

1624 Words | 7 PagesSince there was always energy loss in actual practice situation, the calculated natural frequency should be theoretically lower than directly measured natural frequency. In conclusion, this assumption as mentioned above would be proven by analyzing the results. Description of Apparatus Fig.1 A schematic diagram of the main apparatus. Figure 1 showed the plane view of the spring-mass-pulley system that was used in this experiment. As shown in the diagram, the apparatus consisted of a spring, a pulley, a mass less rope (light cord) and a weighted body.

## Interlaminar Shear Strength of Fibre-Reinforced

2744 Words | 11 PagesInterlaminar shear strength of fi bre- reinforced com posites M. F. M A R K H A M and D. DAWSON An analysis is given of the stress distribution between two grooves cut on opposite faces of a fibre-reinforced composite when a tensile stress is applied to the ends. If this loading system is used to produce failure in shear, it has been shown that the fracture surface is always on the centre plane of the test piece. Hence, values of the interlaminar shear strength derived from this technique are found to be more consistent than those resulting from the widely used 3-point short beam bend test where the fracture pattern can be complex. Examples of the measurement of interlaminar shear stress for several types of fibre reinforced composites are given using the technique and analysis described in this paper. Several methods have been suggested for the measurement of interlaminar shear strength of fibre-reinforced composites.

### Calculating Deflection of a Statically Indeterminate Beam Under Loading

3332 Words | 14 Pages### Hydraulics - Flow in Rough & Smooth Pipes

410 Words | 2 Pages### Torsion of Circular Shaft

386 Words | 2 Pages### Rotational Equillibrium Essay

410 Words | 2 Pages### Mass, Volume And Density

1696 Words | 7 Pages### Absract on "The Phenomena of Rupture and Flow in Solids"

502 Words | 3 Pages### Strain Hardening Essay

1201 Words | 5 Pages### Dicussion About Experiment in Resonance Tube

636 Words | 3 Pages### Elementary Vibrations Experiment

1624 Words | 7 Pages### Interlaminar Shear Strength of Fibre-Reinforced

2744 Words | 11 Pages