AEE 3261 Aerospace Structures Laboratory Stress Concentrations Experiments Report Guidelines - This laboratory report, covering stress concentration experiments is due on the date specified in Canvas, and turned in through TurnItIn. - It is explicitly forbidden for you to access lab reports from previous years for any purpose whatsoever. They may not be used ‘as a template.’ They are not a valid resource to help you if you feel you don’t understand what to do. Do not download an old lab report. Do not look at one. Don’t even think about doing it. If you have questions or are unclear what to do, the proper course of action is contact your GSA or Dr. Swenson. - This laboratory requires a full, formal laboratory report (unlike the Exercise Reports, which permitted a briefer format.) - General guidelines for report formatting are given in Section 2.2 of the Reference Material in Canvas - The file called “2-2 Format Report Requirements.pdf” provide generic formatting convention specified in that document. In particular, please observe the standards described for the presentation of graphs and tables - This document provides specific directions for the Stress Concentrations Lab. Introduction: Describe the purpose of the experiments conducted. Include paragraphs on each of the following: • Stress concentration theory as relevant to the various tests conducted. • Find and describe at least two engineering examples (other than the deHavilland Comet, which is covered in AEE 4281) where stress concentration was a significant factor in an aerospace engineering failure. Provide technical detail about each case and provide citations to external sources. • Explain what is a S-N diagram, and what is its purpose. Procedure: • Describe the test specimens that were used in the testing program, and what one hopes to learn by testing them. • Show a “test matrix” (i.e. a listing of what specimens were made of what materials and tested under what conditions) in a concise, easy-to-understand table. (This is in addition to describing the various test specimens and test types the written text.) • Discuss the instrumentation of your test specimens. What data were collected. • Describe the equipment used (the electromechanical uniaxial testing machine used for quasistatic tests the associated DAQ hardware). Explain their basic operating principle (not the step-by-step operating procedure), the capacity of the systems and the sensitivity of measuring devices used. • Summarize the testing and data acquisition procedures (two to three paragraphs). • Note: the procedure should be written in narrative form (i.e. paragraphs), not a bullet point list or a numbered step-by-step set of instructions. 1 Results: All significant results should be summarized in a clear tables in addition to being described in the body of the report. • Summarize the physical measurements of your specimens in a table. Quasistatic Loading • For the notched specimens tabulate the failure loads, in pounds. • Show plots for all static test specimens according to the following:  For each 1” wide stress concentration specimen plot nominal axial stress versus displacement on a single set of axes.  For the 4-inch wide stress concentration specimen, plot the stress distribution across the line containing the strain gages for several values of applied load based on strain gage readings. Observe the following for these plots: ▪ Remove extraneous data from the beginning of the test pertaining to the time between when DAQ was turned on and the actual beginning of loading, if relevant. ▪ For the hole specimens define axial stress in the plots as the nominal stress (force divided by the minimum cross-section area across the hole). ▪ If plotting in Excel, DO NOT use the ‘smooth curve’ option to connect the data points with a wavy line. Instead use the ‘XY Scatter’ option and do one of the following: ▪ If there is a high density of data points such that curve symbols (e.g. the squares that mark the data points) of reasonable size would blur together, connect the points with straight lines and turn off curve symbols (no circles, no squares etc at each data point). [This is most likely what you’ll want to do for the hole and notch specimens.] ▪ If the data points are sparse, include the data points as curve symbols only; do not ‘connect the dots’ with any lines. ▪ Cartoon samples of some of the required plots are included below. • Make the graphs look good. Properly label axes and lines. The aesthetics of the graphs will be a graded part of this assignment. Discussion: • Indicate the comparison in failure load between the two different 1” wide notched test specimen types. Explain why it is so. • For the 4-inch wide stress concentration specimen, determine the stress concentration factor for based on strain gage data and compare it with a theoretical value. (Cite source) • Discuss sources of error in your stress concentration factor measurements including the following points. Be as quantitative as possible. Please take this section seriously! Don’t just make vague statements like “there was human error”:  Influence on the results due to the finite size of the gages  Influence on the results of the position of the gages.  Other effects that may influence the results Conclusions: • Describe what was learned from the experiment. o Give key points in a bullet-point format. 2  Address the topic of stress concentrations and their relevance in static failure and fatigue life. Recommendations: • How could the experiment be improved? What feedback do you have to offer? References: • Cite appropriate references using AIAA citation format. 3 Appendix: Schematic representations of some required graphs. The following are cartoonish representations of some of the graphs required for this lab report. Detailed instructions are given above and where there are contradictions between the written instructions above and these simplified sketches, follow the written instructions. Figure 1: Illustration of plots required for each dogbone specimen. The thin lines represent trendlines or computed lines.* Note: only four gage locations are actually used. Figure 2: Illustration of plot required for the four-inch wide stress concentration specimen. Be sure to label units on axes. * If the experimental data set is so fully populated that the curve symbols for the computed data points would blur into a thick line, turn off the curve symbols and connect the data points with straight lines (do not use “smooth line” option in Excel). 4 FYI, here are dimensions of the wide specimen, showing placement of the strain gages. Fatigue test specimen geometry: 5 2.2 Laboratory Report Writing and Formatting An often overlooked aspect of engineering is communication. While many people may find complicated analyses, construction of hardware, or experimentation to be the most satisfying parts of engineering, one needs to keep in mind that these pursuits are of little value if the results of these efforts are not properly communicated. In aerospace engineering, particularly, where projects typically involve hundreds, if not thousands, of people working together to a common goal, communication is especially important. To meet this need, organizations involved in engineering pursuits specify formatting conventions for transmitting technical information. Regardless of the formatting requirements, however, keep in mind that the primary goal of technical communication is clarity. In the Aerospace Structures Laboratory, we will conduct three multi-week experiments. Each of these expreiments will be reported in a formal lab report. These reports are the major component of the grade in this course. The reports will be graded not only on their technical content, but also on how effectively the reports communicate the method and results of the experiment. Specifications for the laboratory reports are given in the remainder of this document. General Requirements: All lab reports must be prepared in a professional manner. Lab reports must be typed using word processing software, and all figures and graphs should be created using computer software. Freehand drawings and graphs should not appear in a lab report. (All students should currently have access to computer facilities on campus. If you do not currently have access to a computer account, please see the instructor.) Format Template: Each report should contain the following sections: Title Page: Florida Institute of Technology Aerospace Engineering Program MAE 4284-0x Title of Experiment Date(s) Performed Your Name Group Members: Names of group members Introduction: This section introduces the topic of the laboratory and addresses the principle issues of the experiment. This section may be relatively brief, but it must prepare the reader for the material that follows. Procedure: This section describes what you did and how you did it. The procedure should be written in sufficient detail such that a technically competent reader would be capable of repeating 1 the experiment based solely on the content of this section. Please write the procedure in a prose format, and not as a numbered list of steps. Complete dimensions and composition of test specimens should be indicated. In many cases, it is useful to provide a ‘test matrix,’ which is a compact table that indicates the different types of tests that are conducted, showing values of key variables that differ between tests. There is no single format for a test matrix, but the following is a typical sample taken form a Web search. http://www.emeraldinsight.com/content_images/fig/2190180305020.png Descriptions of the capacity and capability of test equipment should be given, if known. (Note that model names and numbers may be used to satisfy this requirement if information on the equipment is not readily available. For example, the phrase “Drop tower” alone does not fully specify the nature of the machine. The reader would not know the capacity of the machine. What is its maximum velocity? How much weight can it handle? If, instead, you write “Dynatup 8250 drop weight impact test machine” then the reader can contact the manufacture to find out the specifications of the machine. Similarly, a sentence like, “The specimen was loaded in a universal testing machine,” does not convey enough information about the apparatus. The reader is left to wonder whether the capacity of the machine is appropriate for the specimen size you are using, and may wonder about other details as well. A better approach would be to say something like, “The specimen was loaded in a 2 kip capacity, screw-driven, bench-top universal load frame.”) Sketches and figures should be used to illustrate details of an experimental set-up that defy written description. (Remember, a picture is worth a thousand words.) Results: This is the section where data from testing, analysis, etc are presented. Results should be presented in tabular or graphical form for clarity. “Raw data” should rarely, if ever, be included in the body of a report. If relevant, raw data should be put in an appendix. Sufficient explanation should be given to explain how the data presented in the results section were obtained from the experimental procedures described in the procedure section. Note that analyses, opinions, or other discussion of the data should NOT be contained within this section. 2 This is the place where the data are first presented, so the reader can view them with an open mind before you proceed to discuss how YOU analyzed the data. Discussion: This section is the place where the analytical work is done. Now you may begin to analyze the data and determine what insights you may derive from them. This section will be the place where you compare the experimental results with theory. Discussions of errors and how they influence the results and the comparison with theory may be contained here. Further manipulations of the data (for example, you may use a curve-fitting procedure to approximate the behavior of the data) may be discussed here. Be sure to explain carefully any calculations you make. Show relevant equations and explain them. Most importantly, do not rush through the discussion section. Take your time, and carefully consider your results and how they relate to what you know about structural analysis. This section is very important. Conclusions: In this section, you address the broad issues of the experiment. Were the objectives indicated in the introduction met? If you are comparing an experiment to theory, was the comparison successful? Why, or why not? Note that statements such as “I learned a lot from this experiment,” are not proper conclusions for a technical report and should not be included in this section. Conclusions should directly relate to the experiment, whether the experimental data corresponded to theory, or whether the structures behaved in the expected fashion. Let the strength of the insights you make in the conclusions section demonstrate what you learned from a given exercise. Diffuse statements about the educational benefits (or lack thereof) of a given experiment may more properly be included in the following section. Recommendations: This section gives you a chance to give some feedback on the experiment. Was the procedure flawed in some way? Could the experiment be improved to give more insight into the problem? Graphs, Tables and other Figures: All figures must have a caption, and must be referred to, by number, in the body of the report. Figures should be neat, and should clearly convey the information they contain. Tables While the use of spreadsheets to manipulate experimental data is encouraged, it is forbidden for “raw” spreadsheet data to appear in a report. Spreadsheets are generally not able to meet the formatting requirements of a formal document: subscripts and Greek letters may not be accessible. Furthermore, you may use your own personal shorthand when labeling cells in a spreadsheet, and certain rows and columns might not be relevant to the report. Instead of simply importing a spreadsheet into a document and using it as-is, the spreadsheet must be substantially modified to appear in the report. A better approach is to import the spreadsheet data into your word processor’s table editor and format the resulting table appropriately. Once you learn how to do this, it is not difficult, and the improvement is tremendous. The tables in Figure 2.2.1 illustrate this point. On the left is a small Excel spreadsheet that I included in this document by inserting the spreadsheet file directly into this document. It was quick, but the format is terrible. 3 On the right is the same spreadsheet converted into a table and modified slightly. (Note that I also corrected some other errors). Spec. # sigma sigma y ult 1 150 121 2 137 134 3 124.67 102.333 Specimen 1 2 3 σult, [MPa] 150 137 125 σY, [MPa] 121 134 102 Figure 2.2.1 Unacceptable (left) and acceptable (right) table formatting Graphs A discussion of proper formatting for graphs taken from Mechanical Measurements, 5th edition by Beckwith, Marangoni and Leinhard is included here. Be sure to study these requirements carefully and to use these concepts when preparing graphs for your reports. If you examine these pages, you will quickly lean that Microsoft Excel does not produce properly formatted graphs by default. You must manipulate the graphs that these software packages spit out to obtain properly formatted graphs for inclusion in a report. 4 5 6 Tension Testing Procedure Testing Machine and Software Start-Up • Verify that the correct wedge grips are installed. Note that there are two sizes of wedge insert, one for gripping specimens up to about 0.25 inches in thickness and one for gripping thicker specimens. If it is not possible to close the specimen on the specimen, the wrong wedge inserts may be in place. • Verify that the circuit breaker (in room 117 on the west wall near the air handler, switch is labeled ‘Tinius Olsen 60kip’) is on. • Turn on equipment: o UPS power supply o Computer o Monitor o Controller (rocker switch) o Large switch on side of machine o Activate drive mechanism by turning green knob to the right then releasing • When computer is booted up, log on. • Open the Quattro control and data acquisition program o Often you get an error message saying something to the effect of ‘unable to communicate, if problem persists cycle controller power.’ If so, cycle the power on the controller and then click ‘OK” to the question asking if you want to retry. It should then start up the program. Note: There is a switch on the main console (the black podium) that lists “Speed” as Fast or Slow. This sets the internal gear ratio for the machine. Under the fast setting, the maximum force that can be supported is approximately 8,800 pounds. If higher load levels are needed, you must use the ‘slow’ setting. Note, however, that the jog is exceptionally slow in the ‘slow’ setting so there may be a need to switch back and forth for high load tests. For Tension Testing of Notch, and Hole Specimens that are to be loaded to failure: • • • Inside the Quattro program, find the “Default Workspace Tab” and expand Test Procedures by clicking on the triangle next to it. Select “Tension Test No EXT MAE4284” for the circular hole and square notch specimens (this file does not include the extensometer). To select a test procedure, double click on the name. Browse through the tabs. In the first tab, enter correct values for the width and thickness of the dogbone specimen or the net section width cross-section in the stress concentration specimen (this should be about ¼ inch) and the thickness of the specimen. Also, enter a unique specimen identifier and update the material property type as necessary. Right click and “save” to store this data. Zero the load. In the “Channels” window, click the blue “Ø” button on the right hand side of the load row. 1 • • • • Position the crosshead to accommodate the spacing of the specimens: o Verify that there is no obstruction in the path of the crosshead or grip o Verify that the “jog rate” is set to an appropriate number (for large adjustment, a rate of about 5 inches per minute is good, but after making coarse adjustments, reset it to 1 inch per minute so it is ready for fine positioning adjustments. o Use the jog up or down buttons (either on the computer window or using the remote control switch) to position the cross-head. Note that the height of the wedges changes a bit when tightening the grips, so be sure to leave a little excess length, otherwise it might not be able to clamp fully. There should be about a quarter inch of gap on each end after tightening the grip. A little more is OK, but not too much more. o Note that on the vertical posts there are two black rings with yellow bands, one below the crosshead and one above. These are safety stops. If the crosshead hits these things, the machine shuts down. Slide them up or down as necessary to make room, but do be sure to leave them in place such that the machine will stop before allowing the grips to contact each other. Once the cross-head is in position, zero the displacement. Click the blue “Ø” button on the right hand side of the displacement row. This will allow you to use the ‘home’ button after each test to reset the machine for each additional specimen. Put the specimen in the between the grips and tighten the upper grip by rotating the handles attached to the grip. o Make sure the specimen is aligned vertically. o Make sure that the full length of the grip section is engaged for dogbones, or that about 2 inches in length is gripped for stress concentration specimens. Manually rotate the upper grip assembly about the vertical axis to align with the lower grip if necessary. (This requires a moderate amount of force.) Attach and balance strain gages: • Clip in strain gages to the posts on the strain gage connector box using spring clips. The red post should have the wire that connects alone to the strain gage. The other two wires are arbitrary. If you have a two wire installation, use a jumper wire to connect the white and yellow posts. • To balance the gages requires opening the “Calibrate” tab. (If it is not already open, use “Utilities/Calibrate” from the main menu. This area is password controlled. The password is quattro. Make sure you only use the Auxiliary tabs in the calibrate tab. Do not alter calibration data for any other channel. • Go to the Auxiliary tab, and make sure that it is set to the same transducer file that will be used in the data acquisition program. Exit the tab, then renter the tab then right click and “save” to store this data. • Note that there is a big window reading “Counts” with a bold number that is dancing a bit. Use this number to balance. The objective is to get this number to be zero, but full scale is about 130,000 so be satisfied with anything in the double 2 • • • digits or less. Balance the bridge using the small screwdriver to turn the small screw visible through the plastic cover of the strain gage connector box. Do not use excessive force on the screwdriver. If the required force increases before reaching balance (and it the screwdriver is not dragging against the plastic hole creating a friction force), you have hit a mechanical stop and it should not be turned further. Disconnect the gage and verify that its resistance is in tolerance before trying again. After all gages are balanced, try to verify that a live signal is obtained by deflecting the free end of the specimen slightly. You should see the numbers in the Auxiliary columns move. Note: balancing must be repeated for each specimen you install! Grip the lower end of the specimen by tightening the screw on that grip. Be careful to avoid torqueing the specimen during this operation. It might be a two person job. Hit the zero buttons next to each active “Auxiliary’ button to zero the strains (correcting for any deviations left over from the balancing procedure. Note: At the moment, I have not implemented a shunt calibration procedure for these strain gages. Therefore the calibration will be somewhat off, and there might then be some systematic error in the results computed in this lab. This will be hopefully fixed in the future. Running the test • Verify that a specimen identifier and geometry data have been added to the data acquisition fields in the test procedure. Right click and “save” to store this data. • Visually inspect the test specimen to confirm it is gripped and no obstruction is in the way. • Hit the green ‘play button’ and the test should run. The first phase of test loads at a relatively slow rate. • Monitor the load throughout the test. Someone should call out load levels periodically. “One thousand pounds” “Two thousand pounds” etc. Other students should monitor the gage readings to see if they make sense. • When yielding occurs, the load will flatten out. • After you are sure that loading has passed the yield point, hit the stair step button to move to the next program segment, which increases the loading rate. (Necking produces high strains, and the remainder of the test would be very long if the load rate were kept constant.) • Have students watch the specimen to observe the necking phenomenon. Those with their noses up close to the test specimen should have safety glasses on. • When the specimen fails, the machine should automatically stop. (If not, hit the stop button on the control panel on the monitor –not the emergency stop button!) o The program may ask for comments on the test. Add something, such as a description of the failure and its location. 3 • • • • o The program will ask if you want to save the data. Say yes, and change the file name to something more descriptive (include the specimen designation and lab section number, for example). Remove the broken specimen parts and pass them around so each student can inspect them, sketch the failure surfaces in their notebooks and/or take photos of the broken specimens. Have students record the maximum load in their lab notebooks. Right click on the report (the graph and basic data) and export it as a JPG file, which you should post to Canvas after lab ends. Make sure that the specimen has been removed from the grips, and that there is no obstruction, then click on the ‘home’ button to set up for the next test. The above procedure is OK for the dogbone specimens as well as for the one inch wide stress concentration specimens, except these have no extensometer use. Note that there are no gages on the notch specimen. Otherwise, the procedure should be the same. Large Stress Concentration Specimen The objective of this one is to show how localized the stress concentration is in the proximity of the hole. Note the following: • Although the specimen has six strain gages installed, we are only able to monitor four gages. Use #1 (inside the hole), #2, #3 (the next two closest to the hole) and #6, at the outer edge. • These gages use the 2.055 gage factor. The testing procedure file should already have the right gages in place. Testing procedures: • Reposition the cross-head to accommodate the larger specimen. You might need to increase the jog rate to move it faster, but put it back to 1 in/min when you are done. • Open the “Channels” tab, which should list which load etc transducers are active. Do not alter anything under load or displacement, but note that the strain gages will be under the headings “Auxiliary” “Auxiliary2” etc. Select transducer files according to the Gage Factor of the strain gages in use. E.g. if GF = 2.055 pick one of “Strain gage 2-055a” thru “Strain gage 2-055e” or use similarly named transducers for the 2.100 gages. [These should be correctly set by default.] After the correct selections are entered, Right click and “save” to store this data. • Go to the “Default Workspace” tab, and select from test procedures the procedure named, “Big Stress Conc MAE 4284” • Install the specimen in the grips, tightening the upper grip but leaving the lower grip loose for the moment. • Zero the force 4 • • • • • • • • • Connect the strain gages. Note that this specimen is wired with only two wires per gage. Thus, you will need to use a short jumper wire to join the black and yellow terminals. Open the calibration window and balance the four strain gages using the procedure described above. Tighten the lower grip Zero all four strain gages by clicking the blue “Ø” button on the right hand side of their column in the live data [CHECK NAME] window. Make sure that you have switched to the program for the big stress concentration specimen and then Click the Run program button. The program should slowly load up to 1000 pounds and then return to zero. Nothing dramatic will be visible. Monitor the load during testing. Do not let this specimen break or you will have a big strain gage job to do to replace it! As the test runs, verify that the strain gage numbers make sense. Gage #1 (inside the hole) should be attached to Auxiliary 1 and should read about 3 times as much as Gage #6 (attached to Auxiliary 4), while Gages 2 and 3 should give values only slightly elevated above gage #6. If this is not the case, after the test runs, try to locate a fault in the strain gages (did you forget to zero them before the test? Are the jumper wires left off? Is the red wire shorting against one of the other wires?) and repeat the test. At the end of the test, save the data. Confirm that the load is approximately equal to zero and that the test has stopped, then remove the specimen and set it aside. Data storage • Data must be ‘exported’ before it can be saved and sent to students • Open the Default Workspace Tab, and find your data files under “Test Data,” probably at the bottom of a long list. • For each file: o Hover the mouse over the name and right click, then select “Export…” o Save in a new folder in MyDocuments, click Browse, create a new folder for your lab section (give it a sensible name) and give a sensible name for the data file (based on specimen designation). Comma separated variables is an OK option, easily openable in Excel. Repeat this process for each file. • If you have not already done so, also export the graph/report for each test as a JPG file. • Post data to Canvas. Organize it into folders for each lab section and label it appropriately. System Shut Down: • Shut down data acquisition program. 5 • • • • Turn off switches in the following order: o Drive switch (green switch) o Main power switch to load frame o Controller Shut down computer Turn off monitor Clean up area. Put all used wire in the drawer of wire storage. Put broken specimens in broken specimen box (after they been inspected, sketched, photographed.) 6 Department of Aerospace, Physics and Space Sciences AEE 3261 Aerospace Experimentation Stress Concentrations Lab Overview Lab 3.1 - Tensile failure of a bar with a circular hole Lab 3.2 - Tensile failure of a bar with notch Lab 3.3 - Observe stress concentration factor (SCF) in a plate with a circular hole YouTube Video Links - YouTube video links are provided to help you get up to speed: - Stress CONCENTRATION Factors and Factor of Safety in 11 Minutes! – YouTube - Stress Concentrations and Finite Element Analysis (FEA) | K Factors & Charts | SolidWorks Simulation - YouTube 3 Student Lab Report - Generic lab report expectations that apply to all labs is here: - https://fit.instructure.com/files/45856235/download?download_frd=1 - Stress Concentrations Lab Report Guidance (NOTE -- all directions provided in this document supersedes the generic ones given above): - https://fit.instructure.com/files/45952083/download?download_frd=1 4 Lab 3.1 - Tensile failure of a bar with a circular hole 3.1.1 Students measure the specimen, focusing on the geometry of the reduced area around the notches (see sketch). Look at radius of curvature. Record in notebook. w2 3.1.2 Students predict failure load on a piece of paper and hand to GSA 3.1.3 GSA write predicted loads on board and discuss 3.1.4 GSA guide and demonstrate. Students install specimen by following procedures for gripping, and loading specimens are described in separate document (FRU-116 Tension Testing Procedure) 3.1.5 Students look up material properties w1 L2 d2 d1 Measure thickness NOTE: Do not use the extensometer Lab 3.1 – Square Notch Experiment 3.1.6 Ignore all parts of the document pertaining to strain gages for the notch specimens – we will not use strain gauges. We are going for failure load only, and thus will not measure strains here 3.1.7 Student roles: geometric measurements (all), install test article, run software, observe test article, and call out loads to team. 3.1.8 Students examine, photograph, and sketch in their lab notebooks failed parts after testing 3.1.9 Students record in lab notebook the maximum load as reported in the report shown at the end of each test 3.1.10 Students verify data are being collected by test machine 3.1.11 GSAs email displacement and load data export and share in CANVAS 3.1.12 Data is section specific only – no need to share between sections 3.1.13 GSA ensure max load (please write on board to share between sections) Lab 3.2 - Tensile failure of a bar with notch 3.2.1 Students measure the specimen, focusing on the geometry of the reduced area around the notches (see sketch). Look at radius of curvature. Record in notebook. w4 L1 3.2.2 Students predict failure load on a piece of paper and hand to GSA d 3.2.3 GSA write predicted loads on board and discuss w1 3.2.4 GSA guide and demonstrate. Students install specimen by following procedures for gripping, and loading specimens are described in separate document (FRU-116 Tension Testing Procedure) 3.2.5 Students look up material properties w2 L2 NOTE: Do not use the extensometer Lab 3.1 – Square Notch Experiment 3.2.6 Ignore all parts of the document pertaining to strain gages for the notch specimens – we will not use strain gauges. We are going for failure load only, and thus will not measure strains here 3.2.7 Student roles: geometric measurements (all), install test article, run software, observe test article, and call out loads to team. 3.2.8 Students examine, photograph, and sketch in their lab notebooks failed parts after testing 3.2.9 Students record in lab notebook the maximum load as reported in the report shown at the end of each test 3.2.10 Students verify data are being collected by test machine 3.9.11 GSAs email displacement and load data export and share in CANVAS 3.9.12 Data is section specific only – no need to share between sections 3.9.13 GSA ensure max load (please write on board to share between sections) Lab 3.3 - Observe stress concentration factor (SCF) in a plate with a circular hole NOTES: Do not break this specimen. See instructions for test procedure name. Max load is 1,000 lb. There is only one test specimen to be used by all sections. 3.3.1 Dimensions are in instructions. Students measure distance S1 and S2. Students compute nominal stress. S1 S2 3.3.2 Students follow procedures for gripping, and loading specimens are described in separate document (FRU-116 Tension Testing Procedure) d w1 3.3.3 Student roles: calibrate strain gauges, install test article, run software, observe test article, and call out loads to team. 3.3.4 GSA email results and students share results within lab section for lab report w2 HT 2838.1 3093.1 2806.8 2722.3 2808.0/3097.8 2924.1 2830. 2615.5 28946 2979.7 2818.4 2787 2966 m D
Purchase answer to see full attachment