Strengths Lab Report 1.pdf - PV LAB REPORTS 1 2 Strength of...

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PV LAB REPORTS 1 & 2 Strength of Engineering Materials 48642 Hayden McManus (12555102), Daniel Retief (12545366), Torian Pillay (12553968), Rachael Whitford (12544755) Timothy Eaton (12963676)Spring 2019
1 Contents Open & Closed ended PV ..............................................................................................................................3Objectives .................................................................................................................................................3Equipment .................................................................................................................................................3Test Procedure ..........................................................................................................................................3Open end...............................................................................................................................................3Closed End .............................................................................................................................................3Results .......................................................................................................................................................4Open End:..............................................................................................................................................4Closed End .............................................................................................................................................4Calculations: ..............................................................................................................................................5Analysis & Interpretation of Results .........................................................................................................6PV with Torsion .............................................................................................................................................8Objectives .................................................................................................................................................8Equipment .................................................................................................................................................8Testing Procedure .....................................................................................................................................8Pressure Experiment .............................................................................................................................8Torsion Experiment ...............................................................................................................................8Superposition Experiment ....................................................................................................................9Results .......................................................................................................................................................9Pressure Experiment .............................................................................................................................9Torsion Experiment .............................................................................................................................10Superposition Experiment ..................................................................................................................10Calculations .................................................................................................................................................11References: .................................................................................................................................................12Appendix .....................................................................................................................................................13Calculations for Pressurised cylinder with Open & Closed Ends: ...........................................................136.1 Open End Conditions: ...................................................................................................................13Calculations Closed End conditions: ...................................................................................................13Yield Analysis .......................................................................................................................................17Tresca Max Shear stress Criterion.......................................................................................................17The von Mises max distortion strain energy criterion .....................................................................18
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3 Open & Closed ended PV Objectives The objectives of the lab experiments were to show students the theories taught in class. Specifically, we were to: Verify transformation of strain theory Verify thin walled cylindrical pressure vessel theory Predict the yield of a substance by applying the yield criteria Equipment For this experiment we used a hydraulically pressurised (thin walled) cylinder constructed by aged aluminium alloy 6063. A knob is attached to the front of the cylinder and is used to create the open and closed systems. The cylinder had an outer diameter of 86mm and a thickness of 3mm (inner diameter of 80mm). A foil-type strain gauge with a gauge factor of 1.8 and 2.2 is bonded onto the cylinder. The gauge factors have been compensated in the electrical circuits connected to them, so they have no bearing on the results. See appendix for detailed diagrams of the apparatus. Test Procedure Open end 1.Set the cylinder to the “Open End” condition by bleeding the pressure out and winding the knob in. 2.Ensure that the strain bridge is connected and balanced 3.Pump the pressure to 1 MPa 4.Record the values on gauges at 0˚and 90˚. 5.Repeat steps 2-4 for 2 and 3 MPa 6.Graph results and obtain results for 2.5 MPa Closed End 1.Set the cylinder to the “Closed End” condition by bleeding the pressure out and unwinding the knob 2.Balance the strain bridge 3.Pump the pressure to 1 MPa 4.Read the strain on all gauges 5.Repeat steps 3 and 4 for 2 and 3 MPa
4 Results All measurements are made in micro strain. Open End: P (MPa) ε0˚(με) ε90˚(με) 0 0 0 1 -65 198 2 -138 403 3 -210 607 From the trendline, we can estimate the values at 2.5 MPa: ε0˚@ 2.5MPa= -173.393 μεε90˚@ 2.5MPa= 504.475 μεClosed End P (MPa) ε90˚ε0˚ε30˚ε45˚ε60˚ε90˚0 0 0 0 0 0 0 1 172 30 62 97 133 165 2 341 64 129 198 269 344 3 513 100 196 300 405 504 y = -69.357xy = 201.79x-300-200-100010020030040050060070000.511.522.533.5Strain (με)Pressure (MPa)Open End90˚Linear (0˚)Linear (90˚)
5 From the trendline, we can estimate the values at 2.5 MPa: ε90˚@ 2.5MPa= 427 μεε0˚@ 2.5MPa= 82 μεε30˚@ 2.5MPa= 162.5 μεε45˚@ 2.5MPa= 249 μεε60˚@ 2.5MPa= 337 μεε90˚@ 2.5MPa= 424 μεCalculations: Please refer to the appendix of our report to find the calculations for the pressurised cylinder with open and closed ends.

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