Conference Session

What's New in Mechanics of Materials?

Collection

2006 Annual Conference & Exposition

Authors

Hartley T. Grandin, Worcester Polytechnic Institute; Joseph Rencis, University of Arkansas

Tagged Divisions

Mechanics

distributed loading.Introduction The great majority of undergraduate mechanics of materials textbooks1-50 directly applypreviously derived force-deformation formulas to problems involving the straight bar subjectedto centric axial loading and the straight circular cross-section bar (shaft) subjected to twistingcouples. In both cases, the bars are uniform in cross-section and material, and the concentratedloads are applied at the ends and distributed loads are continuous along the full length. Theforce-deformation formulas are shown in Figures 1 and 2 for bars subjected to centric axialloading and twisting couples, respectively. These formulas, referred to as Material LawFormulas by the authors, are commonly found in mechanics of materials

Conference Session

What's New in Statics?

Collection

2006 Annual Conference & Exposition

Authors

Paul Steif, Carnegie Mellon University; Mary Hansen, Robert Morris University

Tagged Divisions

Mechanics

measurements of knowledgeor skills that are reliable and valid. Based on such psychometric analyses, the test has steadilyimproved each year. The numbers of students taking the test has also increased: 245 in 2003-2004, 1330 in 2004-2005, and 1255 as of the first half of 2005-2006 (with 16 classesparticipating). Only very minor changes to the current version are anticipated for the future.A critical feature of the test is that questions are grouped according to concept. In the 2005-2006 version of the test, there are 9 concepts, with 3 questions per concept. The concepts aregiven in Table 1. Page 11.641.2Table 1. Concepts tested in 2005-2006 version of

Conference Session

What's New in Mechanics of Materials?

Collection

2006 Annual Conference & Exposition

Authors

Nashwan Younis, Indiana University-Purdue University Fort Wayne

Tagged Divisions

Mechanics

of light byreflection and Brewster’s law5. When a polarized beam propagates through a transparent plasticof thickness t, where X and Y are the directions of principal strains at the point underconsideration, the light vector splits and two polarized beams are propagated in planes X and Y.If the strain intensity along X and Y is ε1 and ε2, Brewster established that the relative change inindex of refraction is proportional to the difference of principal strains or: (n x − n y ) = K (ε 1 − ε 2 ) (1)Where n is the index of refraction. The constant K is called the strain-optical coefficient andcharacterizes a physical property of the material. It is a dimensionless constant usuallyestablished by calibration and may be considered

Conference Session

Teaching with Technology in Dynamics and Mechanics of Materials

Collection

2006 Annual Conference & Exposition

Authors

Thomas Nordenholz, California Maritime Academy

Tagged Divisions

Mechanics

will be presented.Finally, there will be a short section describing the basic techniques used by the author toprogram the animation filesI. Introduction.Several engineering educators 1-5 have written on the use of animation in dynamics, vibrations,and controls courses. Certainly, the theory behind the motion of mechanical systems ismathematical and difficult for many students to grasp, and the animation of these systemsprovides enhanced understanding and motivation. Page 11.215.2One common approach to animation involves the use of commercial software such as WorkingModel that simulates motion from objects drawn by the user without any

Conference Session

Teaching with Technology in Dynamics and Mechanics of Materials

Collection

2006 Annual Conference & Exposition

Authors

Salim Haidar, Grand Valley State University; Ali Mohammadzadeh, Grand Valley State University

Tagged Divisions

Mechanics

model example, we propose to evaluate the position, velocity and the time at which the 1pound block leaves the surface of a cylindrical surface on which it slides. The block is assumedto have an initial velocity V0 at the top of the cylinder and is subject to a constraint friction forceof kinetic coefficient of friction, µk (See Figure 1). To achieve a stable numerical solution, weassume, without loss of generality, a specific initial speed of 10 ft/s for the block and considerthe coefficient of kinetic friction between the block and surface to be zero in one case and 0.2 inthe other. The radius of cylinder, r = 5 ft. V0 r

Conference Session

Innovative Teaching Techniques in Mechanics

Collection

2006 Annual Conference & Exposition

Authors

Andrew Szmerekovsky, AFIT; Brian Self, U.S. Air Force Academy

Tagged Divisions

Mechanics

drives the interactive classroom experience,enhancing the students’ critical thinking, problem solving ability, and conceptual understanding.JiTT ExamplesTwo example WarmUps are shown below, one for Dynamics (see Figure 1) and one forMechanics of Materials (see Figure 2). Some sample student responses are provided for eachexample, followed by a discussion on how the instructor might interweave these answers into thelesson.Dynamics. In the first question, students are asked to answer a conceptual question. This type ofquestion can be used to encourage students to read the text, to require them to think at a deeperlevel, or just to introduce the material. The second question is conceptual and requires thestudent to think about what can happen

Conference Session

What's New in Mechanics of Materials?

Collection

2006 Annual Conference & Exposition

Authors

Michael Hennessey, University of St. Thomas; Luke Hacker, University of St. Thomas

Tagged Divisions

Mechanics

-stress as the differential cube rotates,visualization is typically static. What is needed is a true 3D dynamic visualization tool thatpermits one to visualize an arbitrary state-of-stress from the perspective of continuously varyingand arbitrary 3D differential cube orientations, parameterized by a time varying rotation matrix,such as that driven by an Euler matrix with 3 time varying angles.The objective of this educational research project is to: (1) develop the mathematics that permitone to arbitrarily change the orientation of a differential cube and determine the stresses in thenew coordinate system (i.e. 3D tensor change of bases), (2) create a corresponding computer-aided-engineering (CAE) software tool using primarily MATLAB® and

Conference Session

What's New in Statics?

Collection

2006 Annual Conference & Exposition

Authors

Kevin Dong, Cal Poly-San Luis Obispo

Tagged Divisions

Mechanics

Engineering Department torevamp the 2nd year engineering series. The task was to invigorate the students in the College ofArchitecture and Environmental Design (CAED) - all of whom are required to take engineeringcourses – with the goal of increasing pass rates and increasing interest in the subject. In thecollege, Architectural Engineering, Architecture, and Construction Management majors arerequired to take traditional statics and strength of materials courses so this was no small task.During the conceptual stages of course development, six key issues (the 6 I’s) were identified tomake the new series a success: 1. Increase effective contact time 2. Incorporate tactile (kinesthetic) learning1 versus aural (passive) learning in order to

Conference Session

What's New in Statics?

Collection

2006 Annual Conference & Exposition

Authors

Shane Palmquist, Western Kentucky University

Tagged Divisions

Mechanics

engineering education and practice. One such project involving an inspection of ahistoric truss bridge is discussed herein.II. Historic Truss Bridge ProjectStudents working in teams actively participated in a class project involving a preliminaryinspection of a local steel truss bridge. A dead load analysis of the truss superstructure based onas-built conditions was performed.College Street BridgeCollege Street Bridge is a four-span, steel, truss structure which crosses the Barren River inBowling Green, Kentucky (see Figures 1 and 2). Spans 1 through 3 are through trusses, andspan 4 is a pony truss. The historic bridge was built in 1915 and presently serves as a pedestrianbridge. The top chord truss members and the vertical truss members of the

Conference Session

Innovative Teaching Techniques in Mechanics

Collection

2006 Annual Conference & Exposition

Authors

Madhukar Vable, Michigan Technological University

Tagged Divisions

Mechanics

Conference Session

What's New in Statics?

Collection

2006 Annual Conference & Exposition

Authors

Nidal Al-Masoud, Central Connecticut State University

Tagged Divisions

Mechanics

pushbutton is clicked,the GUI invokes the action described on the label of that button in conjunction with the textboxinput, slider input, pull-down menu, or toggle button requirements. One of the best advantagesof the using GUI verses traditional programming is that in GUI it is not necessary to beknowledgeable in programming. Eliminating this requirement forces students to focus on thesubject matter, rather than on debugging and editing programs or learning how to program. Theapplication can also be compiled into a window-based executable format or integrated into JAVAapplets 1.MATLAB is a widely easy-to-use technical computing language that integrates computation,visualization, and programming. More than 800 MatLab-based books are available for

Conference Session

Innovative Teaching Techniques in Mechanics

Collection

2006 Annual Conference & Exposition

Authors

Louis Everett, University of Texas-El Paso; Arunkumar Pennathur; Elsa Villa, University of Texas-El Paso

Tagged Divisions

Mechanics

produce results and began to applytheory covered in class. This paper presents some of the modules or challenge problems that were used in the course.The authors did not create these problems: they were copied from a number of sources anddeveloped to the point that they have classroom materials associated with them. The paper alsopresents the design problem and gives a web link to download the modules and the design. Thesoftware simulations used in class are described and discussed; and assessment of studentattitudes before and after these “interventions” is presented.1 This material is based upon work supported by the National Science Foundation under Grant No. DUE-0411320

Conference Session

Innovative Teaching Techniques in Mechanics

Collection

2006 Annual Conference & Exposition

Authors

Ing-Chang Jong, University of Arkansas

Tagged Divisions

Mechanics

. A virtual work is the work done by force ormoment during a virtual displacement of the body. Fig. 1 Compatible virtual displacement of body AB to position A¦B¦In virtual work method, compatible virtual displacements (besides rigid-body virtual displace-ments) are to be used, where second-order (not first-order) straining of members in a system ispermitted in drawing virtual displacement diagrams. This may initially come across as beingagainst the grain of the usual mentality of rigid bodies held for Statics. Notwithstanding, a work-ing definition is in order. As shown in Fig. 1, a compatible virtual displacement of a body ABis an imaginary displacement resulting from a first-order differential angular displacement fs ofthe body

Conference Session

What's New in Mechanics of Materials?

Collection

2006 Annual Conference & Exposition

Authors

Adam Creuziger, University of Wisconsin-Madison; Wendy Crone, University of Wisconsin-Madison

Tagged Divisions

Mechanics

, based on teaching experience, appears to bea difficult concept for students. Whether this difficulty is due to a single fundamental difficulttopic, a variety of difficult topics, or some other factor has not been addressed in the literature.Because the teaching methods used in this course are similar to how mechanics of materials istaught nationally, the survey results of the study discussed below should be broadly applicable.There are a variety of methods that can be used to determine what concepts are difficult forstudents. For many disciplines, concept inventories have been used to determine what conceptsare most difficult for students. A concept inventory for mechanics of materials (strength ofmaterials) has been developed [1-3]. From this

Conference Session

What's New in Mechanics of Materials?

Collection

2006 Annual Conference & Exposition

Authors

Lucas Passmore, Pennsylvania State University; Aiman Kuzmar, Pennsylvania State University-Fayette

Tagged Divisions

Mechanics

Conference Session

Back to Basics in Mechanics

Collection

2006 Annual Conference & Exposition

Authors

Thomas Malmgren, University of Pittsburgh-Johnstown

Tagged Divisions

Mechanics

examples thatfollow will illustrate the use of CAD-based graphical problem solution to faculty unfamiliar withCAD software to encourage CAD-based graphical analysis in student assignments as well asspark interest in its use for themselves.The first rudimentary example of using graphical analysis with CAD as the solution methodrepresents a typical problem found in Engineering Statics. This force analysis problem requiresfinding the tension in two cables supporting a 200 pound weight. One cable (A) is 45° from thehorizontal upward toward the left while the other (cable B) is 15° from the horizontal upwardtoward the right. From a Free Body Diagram (FBD) shown on the left side of Figure 1, we seethat we know the magnitude and direction of the weight

Conference Session

Back to Basics in Mechanics

Collection

2006 Annual Conference & Exposition

Authors

Robert Martinazzi, University of Pittsburgh-Johnstown; Brian Houston, University of Pittsburgh-Johnstown

Tagged Divisions

Mechanics

points added to their final coursepercentage was welcomed by the students and did serve to motivate them to assist the authors incoming up with some novel ideas. Any student team who did not choose to participate was notpenalized in any manner, but very few teams chose this latter option. The students were given a week to develop their ideas. They were required to presenttheir suggestions in a formal written format to be evaluated by the instructors. After all of theproposed reengineered quiz ideas were evaluated, 33% of the students earned 2% points to beadded to their final grade, 54% earned 1% point, and 13% of the students did not receive anybonus points for their efforts. Names were chosen by the instructors to best illustrate

Conference Session

Teaching with Technology in Dynamics and Mechanics of Materials

Collection

2006 Annual Conference & Exposition

Authors

Honghui Yu, The City College of New York; Feridun Delale, The City College of New York

Tagged Divisions

Mechanics

for the course and instructor evaluation, student feedbackappears to be very positive. Introduction Mechanics of Materials (MoM) is the first course in solid mechanics, which coversstress, deformation and strength of simple shaped members, and their applications.Topics include concepts of stress and strain, uni-axial loading, torsion, beam bending,column buckling and stress/strain transformation, etc. As a mandatory course, it has farreaching effects in students’ future learning and career development. Since the introduction of Timoshenko’s book, [1] Strength of Materials, the subject Page 11.839.2has become

Conference Session

Innovative Teaching Techniques in Mechanics

Collection

2006 Annual Conference & Exposition

Authors

Shanzhong (Shawn) Duan, South Dakota State University

Tagged Divisions

Mechanics

their designapplications than they could previously.IntroductionAn applied multibody dynamics course is usually offered to mechanical engineeringundergraduates in their senior year and to graduates in their first year. It is an advanced topic andrequires that students have a background in linear algebra, vector-matrix operations, dynamics,numerical analysis, and fundamentals of computer science, as well as in basic programmingskills. The specific contents of multibody dynamics may vary from school to school. Butgenerally speaking, they may contain but are not limited to the following: (1) Multibodykinematics: coordinate transformation matrixes and direction cosines, kinematical formulas,partial velocities, partial angular velocities, Euler

Conference Session

Teaching with Technology in Dynamics and Mechanics of Materials

Collection

2006 Annual Conference & Exposition

Authors

Rungun Nathan, Villanova University

Tagged Divisions

Mechanics

few years to incorporate several of these findings in multimedia teaching aids usingoverlaid transparencies, electronic slides, fill-in worksheets, streaming videos, tablet-pc,one minute clarification, etc. The next few paragraphs will describe several of thesemodes used in the classroom and discuss the observations and feedback of students.Chalkboard to Transparencies…To begin the transition from chalkboard teaching, about four years ago work on creatingthoughtful and content driven transparencies utilizing several overlays and colored penswere commenced. For example, to demonstrate the idea of reduction of a system offorces on a rigid body to a single force and moment of couple overlaid several slides(figure 1) were created. First the idea