diff --git a/README.md b/README.md index e38f33a..d11f601 100644 --- a/README.md +++ b/README.md @@ -1,22 +1,16 @@ # Introduction to Sensors and Data Analysis -## ME 3263 Fall 2018 +## ME 3263 Fall 2020 [ME 3263 Lab Report Rubric](./ME3263-grading_rubric.pdf) Labs 0 and 1 have a 3-page limit and 2-figure limit. Labs 2-6 have a 5-page limit and 4-figure limit. You can add additional pages and figures in an -Appendix. The Appendix will not be formally graded, but you can use it to refer +Appendix. The Appendix will not be graded, but you can use it to refer to data, methods, or diagrams that are relevant. The report is scored 0-100. Over 70 is passing. Late submissions receive 10 point penalty per day. -Part of your "writing assignments" grade is based upon the reports that you make -the final edits and improve the flow. The first author listed will get credit -for the writing assignment portions. Take turns as first author and co-author. -The group shares the pass/fail grade for the "lab report" grade. - - # Repository for laboratory notebooks *To access notebooks and interactive lab material, sign into github.uconn.edu, then follow the link to the class server.* @@ -24,168 +18,8 @@ then follow the link to the class server.* # [ugmelab.uconn.edu](https://ugmelab.uconn.edu) # ME3263 Introduction to Sensors and Data Analysis (Fall 2018) -## Lab #5 Mass Measurement Device with Cantilever beam - -[Lab 5 github files](https://github.uconn.edu/rcc02007/ME3263-Lab_05.git) - -# Mass measurement contest - -In the mass measurement contest, you will use natural frequency shifts to -determine the mass of an object. There are three locations you can mount the -object as seen in Figure 1, where the object is mounted in position 2. The -experimental procedure only involves measuring natural frequency with the mass -mounted in different positions. You can create an *engineering model* as we will -do with experimental results from Ghatkesar *et al.* 2007 -[\[1\]](./ghatkesar-et-al-2007_higher-mode-mass-sensors.pdf), as described in -section 2. - -You can use the modal analysis in **Ansys** -[\[2\]](https://ansyshelp.ansys.com/account/secured?returnurl=/Views/Secured/corp/main_page.html) -and apply a point mass to get predicted changes in natural frequencies. This -will create a table of values for your given cantilever for known masses for -*interpolation* as described in section 3. - -**Rules of Contest** - -1. The masses must not leave the lab - -2. You cannot mount other known masses to the cantilever - -3. You must report your uncertainty in your mass measurement to enter the -competition - -4. You must report your serial number "TJM 01-TJM 12" to enter the competition - -6. You may use the following tools and software: strain gage or accelerometer -(not both), calipers, Ansys, Labview, Python, Matlab, and Excel - -**Winners of the contest** - -There will be two sets of winners for the contest: - -1. Lab group with the most accurate mass measurement calculated with -$A=|m_{reported}-m_{actual}|$ - -2. Lab section with the most precise mass measurement calculated with -$P=\sum_{i=1}^{N}(m_{reported}-m_{actual})^2$ - -Where $A$ is the accuracy, $P$ is the precision, $m_{reported}$ is the reported -mass from your experiment, and $m_{actual}$ is the actual mass of the object, -and $N$ is the total number of lab groups in a section. The group and section -with smallest A and P, respectively will win prizes. The prizes are as such - -1. ** \$100 cash prize** put into your student accounts ($50/group member for -group of 2) - -2. **Donuts/cookies** brought to your lab section - -**Lab #5 report** should include details of the following - -1. Your design of experiments - -2. Your measured results - -3. Your predicted results from Ansys - -4. Your final calibration process for measuring a mass based upon natural -frequency changes - - -## Lab #4 Predicting Natural Frequencies with the Finite Element Method - - -### What is the Finite Element Method? - -The Euler-Lagrange dynamic beam equation is an example of a partial differential -equation (PDE). These equations are common in many engineering applications e.g. -solid mechanics, electromagnetics, fluid mechanics, and quantum mechanics. The -finite element method solves PDEs. The FEM process involves two steps to create -matrices for a computer algorithm solution. First, the PDE is integrated from -the strong form to the weak form. Second, an approximation of the variable -"shapes" within each "element" is created to convert the integrals and -derivatives into matrices -[(1)](http://bcs.wiley.com/he-bcs/Books?action=index&bcsId=3625&itemId=0470035803). -For elements with nodes only at vertices, such as cubes (hexahedrons) or -pyramids (tetrahedrals), the "shape" function is linear for displacement. - -[Lab 4 github files](https://github.uconn.edu/rcc02007/ME3263-Lab_04.git) - -## Lab #3 Measuring Natural Frequencies - -### What are natural frequencies - -In free vibration (i.e., no external forcing), structural components -oscillate at specified frequencies or combinations of frequencies. Since -these vibrations are unforced, the associated frequencies are referred -to as natural frequencies; it's how the system vibrates if left to -behave on its own. In contrast, driven linear systems vibrate at the -driving frequency. An amplification of the response (called resonance) -occurs when the driving frequency coincides with one of the natural -frequencies. In short, the system is driven at a frequency at which it -likes to vibrate. Large amplitude oscillations are the result. So it is -important to know what the natural frequencies are *a priori* so you can -avoid driving the system into resonance. - -[Lab 3 github files](https://github.uconn.edu/rcc02007/ME3263-Lab_03.git) - -# Lab #2 - Static beam deflections with strain gage - -## What is a Strain Gage? - -A strain gage consists of a looped wire that is embedded in a thin backing. Two -copper coated tabs serve as solder points for the leads. See Figure 1a. The -strain gage is mounted to the structure, whose deformation is to be measured. As -the structure deforms, the wire stretches (increasing its net length ) and its -electrical resistance changes: $R=\rho L/A$, where $\rho$ is the material -resistivity, $L$ is the total length of the wire, and $A$ is the cross sectional -area of the wire. Note that as $L$ increases, the cross sectional area changes -as -well due to the Poisson contraction; the resistivity also changes. - -![Figure 1: a) A typical strain gage. b) One common setup: the gage is -mounted to measure the x-direction strain on the top surface. It's -engaged in a quarter bridge configuration of the Wheatstone bridge -circuit.](./figure_01.png) - -*Figure 1: a) A typical strain gage. b) One common setup: the gage is -mounted to measure the x-direction strain on the top surface. It's -engaged in a quarter bridge configuration of the Wheatstone bridge -circuit.* - - -# Lab #1 - Measurements of machining precision and accuracy - -[Lab 1 github files](https://github.uconn.edu/rcc02007/ME3263_Lab-01.git) - -**Outline and figures due in week 4 at beginning of lab** - -**Final report due day before lab by 11:59pm** - -**How can you measure something?** - -All measurements have traceable standards. There are seven base units in SI - -meter (length), second (time), Mole (amount of substance), Ampere (electric -current), Kelvin (temperature), Candela (Luminous intensity), and kilogram -(mass) 1. Any measurement you make should have some method to check against a -reference. In this lab, we will use calipers that measure dimensions i.e. -meter 1E-3 (length). Calipers can always be verified to work with gage -blocks. - -**Sources of measurement variations** - -No measurement is exact. No surface is compeletely flat. Every measurement you -make has two types of uncertainties, systematic and random. Systematic -uncertainties come from faults in your assumptions or equipment. - # Lab #0 - Introduction to the Student t-test -**Outline and figures due Wed 9/5 by 5pm** - -**Final report due Thu 9/13 by 5pm** - -[Lab 0 interactive notebook in ipynb jupyter -notebook](https://mybinder.org/v2/git/https%3A%2F%2Fgithub.uconn.edu%2Frcc02007%2FME3263_Lab-0.git/f25072f2e708c231ea05040cab6aae2699a7be6f) - We use statistics to draw conclusions from limited data. No measurement is exact. Every measurement you make has two types of uncertainties, *systematic* and *random*. *Systematic* uncertainties come from faults in your assumptions or @@ -197,3 +31,7 @@ model. Here are some examples for caliper measurements: In theory, all uncertainies could be accounted for by factoring in all physics in your readings. In reality, there is a diminishing return on investment for this practice. So we use some statistical insights to draw conclusions. + +# Labs 1-6 coming soon +check [HuskyCT](lms.uconn.edu), [Piazza](piazza.com/uconn/fall2020/me3263/home), and +[ME3263 repo](https://github.uconn.edu/rcc02007/me3263_labs) for updates!