Document

.docx

School

The University of Tennessee, Chattanooga *

*We aren’t endorsed by this school

Course

2460

Subject

Industrial Engineering

Date

Jan 9, 2024

Type

docx

Pages

Uploaded by ash77hem

Shear Strength of Bolts: Data Analysis and Reporting Specifications XI. Analysis of Data Recall the objective of Mini Lab: Validate the formula, equation 1, predicting the critical load to failure for a bolt loaded in double shear. This will be accomplished by experimentally observing the failure load then comparing that to the load predicted by theory. XII. Prepare Mini Lab Report Prepare a mini lab report in accordance with the following guidelines: Refer to Sample Mini Report at end of this document. Format: Memo style as follows: Date: mo/day/year To: Instructor From: Student name Subject: Lab ID and Lab Name Content The mini lab report shall contain three sections only: Results, Q&A, and Appendix as specified below: I. Results: This section shall present results in the form of Tables and Captioned Figures as specified: Tables One table required; Table 1: Compare predicted and observed of: P CRIT : Failure loads (4 specimens) τ ULT : Ultimate shear strength

Table shall report the uncertainties in the observed and predicted values ± Δ OBS’D and ± Δ PRED’D Table shall report the % deviation %deviation=(observed-predicted)predicted100 Table shall report the Total Error as a % %Total Error =∆ObservedObserved+∆PredictedPredicted*100 Tables shall report values with appropriate significant figures. Refer to Table 1 at the end of this document for an example of the typical comparative table. Captioned Figures: One captioned figure is required: Figure 1 One chart shall contain two plots: One plot of the observed P CRIT vs. Area Observed: plot with ‘markers’ NO LINES One plot of the predicted P CRIT vs. Area Predicted: plot with smooth solid lines NO MARKERS ALL captioned figures shall be numbered and captioned Axes of plots shall be labeled with appropriate units Markers will describe observed data Solid lines will describe theoretical, predicted or published behaviors Captions shall contain three to four descriptive sentences to identify the plots and to highlight the significance of the information revealed in the plot. Refer to Figure 2 below for an example of the typical captioned figure. II. Q&A

This section gives you an opportunity to demonstrate the extent that you know, understand and are able to apply the principles associated with the Mini Lab. Please keep your responses short, concise and thoughtful. Please reply in complete sentences. Bulleted lists are fine if appropriate. Number each response using the Q#.# below and please re- state each question immediately prior to each response. Issue 1: Assumptions: Don’t these make an ass out of u and me?? The objective of this lab is to experimentally validate the formulas for predicting the load to failure of bolts in shear. The main assumption is that failure load is proportional to the cross section area. See eq. 1above. Q1.1 Is the observed behavior consistent with the assumed dependence on area? Explain. Now consider the test fixture. It is intended to load the bolt in pure shear. Inspect the fixture. Inspect the bolt specimens after failure. Q1.2.a What evidence would suggest the bolt was in pure shear when loaded to failure? Q1.2.b What evidence would suggest the bolt was not in pure shear when loaded to failure? Q1.2.c To what extent were the bolts specimens actually loaded in pure shear? Explain. Take note of differences between smaller diameter and larger diameter specimens. Issue 2 Conclusions: Is the Theory, Prediction or Publication Valid?? Criterion for validation of a prediction by experimental observation is somewhat arbitrary. In this lab (ENGR2460L) a prediction is deemed validated if the %Deviation < 25% AND if the %Total Error <25%. Even if arbitrary, this quantification provides a sound basis for Conclusions related to validation. The Objective(s) of the Mini Lab cited in II above is to experimentally validate the formulas for predicting the torsional spring constant for straight and tapered shafts. Have the objectives been met? Depending on your assessment of the lab results, you might conclude that 1) All Objectives were achieved or 2) No Objectives were achieved or 3) Some Objectives were achieved and others were not. Therefore, answer a or b or c, below. Q2.1.a If you conclude that All objectives were achieved, explain how the results reported in the Tables including the % deviation and total error are evidence of the validations. Q2.1.b If you conclude that No objectives were achieved, explain how the results reported in the Tables including the % deviation and total error are evidence of the failure to validate. Q2.1.c If you conclude that some objectives were achieved and some were not, explain how the quantified results reported in the Tables including the % deviation and total error are evidence of the validations or evidence of failure to validate.

Issue 3 Recommendations: How Can This Study Be Improved?? Think of Recommendations as advice you would give to the next inquisitive person who might repeat the study, advice that would improve the usefulness or strength of the study. One path to improvement lies in reducing total error. The queries below seek identification of specific recommendations to reduce the error and uncertainty in the predicted and observed results. Q3.1.a Identify the largest single source of error/uncertainty in the Predicted ? Q3.1.b Estimate the magnitude of 3.1.a with respect to the Δ Predicted? Q3.1.c Make a recommendation aimed to reduce the magnitude of the error in 3.1.a. Q3.2.a Identify the largest single source of error/uncertainty in the Observed ? Q3.2.b Estimate the magnitude of 3.2.a with respect to the Δ Observed? Q3.2.c Make a recommendation aimed to reduce the magnitude of the error in 3.2.a. REMEMBER: Experiment Validates Predictor: If Maximum Error is reasonable (say < 20%) AND If Deviation (%) < Maximum Error (%) Appendix Appendix A Measurements & Observations: Include tabulations of all measurements Copy/paste Excel templates, Remove the color used to fill the fields Appendix B Formulas and Sample Computations Estimation of Predicted and Observed Parameter(s) Estimation of Uncertainties in Predicted and Observed Parameter(s) Partial Derivative Method High Low Method Save Lab Report and Convert to PDF

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help