• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Creep in Metals Laboratory Report

Extracts from this document...

Introduction

BE 1310 Creep in Metals Laboratory Report Creep in metals is evaluated by the change in length versus time. For the creep to take place its important to consider the magnitude of the stress as well as the temperature. When evaluating the creep curve, the initial strain has significant effects on the length, which is followed by decrease in the strain rate as the primary creep takes place. The derivative of the primary creep is noted as the steady-state creep rate. After the steady-state creep rate a rapid change in the data will be observed as the strain causes fracture. This time dependent deformation must be considered during engineering design for safety and longevity. Materials and Methods A Sm 106 Mk II creep testing machine was used along with a stop watch and lead specimens in the lab experiment. The creep machine consists of a lever, steel pins that hold the specimen, bearing block, weight hanger, and a dial test indicator. ...read more.

Middle

Sample 1 Sample 2 Sample 3 Area 5.1360 mm2 5.1948 mm2 5.1467 mm2 Table 2: Measurement of the area of our lead specimens. Weights 0.6 kg 0.7 kg 0.8 kg Force 76.1256 N 83.9736 N 91.8216 N Stress Sample 1 14.8220 N/mm2 16.3500 N/mm2 17.8780 N/mm2 Sample 2 14.6542 N/mm2 16.1649 N/mm2 17.6757 N/mm2 Sample 3 14.7911 N/mm2 16.3160 N/mm2 17.8409 N/mm2 Table 3: Measurement of the force and stress of the lead specimens for each load. Time (t) Reading (a) ?Reading (a-a1) Stretch (?l) Strain (?) 0 12.75 0 0 0 15 15.85 3.1000 1.5500 0.4062 30 16.25 3.5000 1.7500 0.4586 45 16.50 3.7500 1.8750 0.4914 60 16.69 3.9400 1.9700 0.5162 15 16.84 4.0900 2.0450 0.5359 30 16.93 4.1800 2.0900 0.5477 45 17.07 4.3200 2.1600 0.5660 60 17.15 4.4000 2.2000 0.5765 15 17.23 4.4800 2.2400 0.5870 30 17.31 4.5600 2.2800 0.5975 45 17.38 4.6300 2.3150 0.6067 60 17.47 4.7200 2.3600 0.6184 15 17.57 4.8200 2.4100 0.6316 30 17.67 4.9200 2.4600 0.6447 45 17.77 5.0200 2.5100 0.6578 60 17.86 5.1100 2.5550 0.6695 15 17.96 5.2100 2.6050 ...read more.

Conclusion

Results and Discussion Load or stress usually occurs to materials at high temperatures. The operating temperature greatly affects the creep, a time dependent deformation, of engineering materials. On the other hand, materials such as lead and polymers can undergo creep at room temperature. The creep curves in each of the three graphs represent the time vs. strain behavior of lead under a constant load at constant temperature. It involves a primary creep, secondary (steady state), tertiary creep and a fracture point. The three lead samples have marginally small differences, approximately 0.3%, which is necessary for consistent results. The SM106K2 creep testing machine allows users to mount the sample and measure the elongation caused by the mass from reading the dial test indicator every 15 seconds. Figure 1 Figure 2 Figure 3 Figure 4 Formula 1 Formula 2 Formula 3 Formula 4 Conclusion Using the three values calculated from the slope of primary creep stage vs. sigma it is possible to solve 'n' for lead. These three data points can be seen in Figure 4. The value of 'n' for lead has been determined to be 11.5775. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our University Degree Engineering section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related University Degree Engineering essays

  1. Field Report - Surveying

    We then add it to our FL value and divide our new figures by two to get the mean value. 2. Calculation for the Reduced Direction Value The calculation for the reduced direction is done by subtracting all the mean values from the angle of the first targeted station.

  2. Tensile test report.

    The load then continued to be applied until the specimen fractured. Results The Breaking strength, tensile strength, percentage elongation and percentage reduction of area after fracture were tabulated from the results for Steel, Duralmin and Copper. The full readings for the Steel tensile test were taken (see Table 1 in appendix)

  1. Airflow and Venturi Experiment Report

    = 2.99*10-2 kg s-1. Discussion Theory suggests that the mass flow rate m? should have the same value all along the air pipe, since mass is conserved and none is stored in the pipe. As might be expected, the mass flow rate calculated using the two different methods is of the same order of magnitude in all three experiments.

  2. The overall objective of this laboratory experiment is to investigate the effects of proportional, ...

    As seen from figure 2.3 and figure 2.5, the larger kp increases the speed of the control system response (as observed from steeper slope and higher value of peak overshoot of figure 5 as compared to slope of figure 3).

  1. Floating crane design. The following report presents an over view of a floating ...

    Since the pontoon is a floating body in water with a constant depth of immersion, it follows that there must be an equal and opposite force opposing the weight force and this is the buoyancy force which acts vertically up through the centre of gravity of the displaced liquid.

  2. Biofuels in the UK - Group report

    The statistics for the UK show that the load factor for biomass energy production is on average 55%, meaning nearly half of the installed capacity is not being used (Figure 5)[7]. Figure 3: Shows the total installed capacity for renewable resources in the UK.

  1. In this essay, the chemical structure of two polymers, polyethylene (PE) and polystyrene (PS) ...

    Once these were calculated, the graph of stress against stain could be created. Below is a table of the information obtained from the graphs: Properties Polyethylene (thin) Polyethylene (thick) Polystyrene Sample 1 Sample 2 Sample 1 Sample 2 Sample 1 Sample 2 Young's Modulus (GPa)

  2. Measuring the Creep of Lead

    The load is varied in each of the three tests and observations are made on the results. Theory Creep Creep is a time dependent deformation that occurs under a constant applied load and temperature. The rate of creep is influenced by temperature and creep generally occurs at a high temperature.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work