M. Conner Name: A 1/60 scale model truss bridge is to be designed and built using standard file folders.

Transcription

1 M. Cnner Name: EA2: Truss Design Assignment Date: Perid: Prblem Statement: A 1/60 scale mdel truss bridge is t be designed and built using standard file flders. Design Requirements: The scale mdel must be a truss with a ttal span f 30 cm, rm fr a 10 cm wide radbed, and supprt a distributed lad f ver the central jints cnnecting the bttm crds. The truss shuld be designed with a factr f safety f 1.5. Assignment Deliverables: 1. Material Prperty Testing a. Manufacture and test tensin specimens b. Excel wrkbk fr Material Prperty Data Analysis 2. Truss Design a. Excel wrkbk fr Methd f Jints analyses f A, Warren, Pratt, Hwe, and Waddell trusses with height analysis b. Physical bridge cnsistent with the grup s design made frm file flders 3. Slid Edge Mdel a. Individual part files fr the bars & gusset plates (as a single part), truss tubes, bttm and tp chrds, and lateral bracing b. Assembly f the entire bridge c. Finite element analysis f yur assembled bridge 4. Written Reprt a. Prfreader Dcumentatin (x 2) b. Technical Paper 5. Oral Presentatin a. PwerPint File b. Grup Presentatin Prject Timeline Thery and applicatin f the Methd f Jints Material prperty testing tensile strength Excel wrkbk fr Methd f Jint analyses f A, Warren, Pratt, Hwe, and Waddell trusses Techniques fr creating a slid mdel f the entire bridge Excel wrkbk fr material prperty data analysis

2 Mdificatin f Excel wrkbk fr Methd f Jints t include height analysis Slid Edge mdeling f the designed truss/bridge Finite element analysis f the truss/bridge Manufacturing f physical truss/bridge Bridge testing Wrapping up the technical paper Wrapping up the technical presentatin Grup presentatins Details f Prject Deliverables (Grup deliverables are in italics. All ther deliverables are n an individual basis!) Material Prperty Testing 1. Manufacture and test tensin and cmpressin specimens all test specimens shuld be labeled and kept in the prject bx thrughut the duratin f the prject! 2. Excel Wrkbk fr Material Prperty Data Analysis (Due by the end f schl n Friday, Nvember 4 th ) Truss Design a. A named spreadsheet within the wrkbk cntaining i. A fully frmatted data table (using the cnventins discussed in class) shwing the cllected tensin data, using autmated calculatins t cmpute the actual tensile strength f each specimen. ii. A fully frmatted data table (using the cnventins discussed in class) shwing the mean and standard deviatin fr the tensile strength fr each width bar. b. A named spreadsheet within the wrkbk shwing a graph f the Tensile Strength vs. Bar Width with an apprpriate best-fit line. Prper substitutins and units shuld be made in the equatin fr the best-fit line. 1. Excel Wrkbk fr the Methd f Jints analyses f the five trusses we have analyzed. (Due by the end f schl n Thursday, Nvember 10 th ) a. Include separate, named spreadsheets fr the symblic slutins f the A, Pratt, Hwe, Warren, and Waddell trusses. Each spreadsheet shuld cntain a diagram f the crrespnding truss. b. Use cnditinal frmatting t shw tensile frces in red and cmpressive frces in blue. c. Analyze the impact f the truss height n the internal frces in each member fr yur assigned truss type.

3 M. Cnner 3 EA2: Truss Design Assignment i. Create multiple clumns fr varying heights n the spreadsheet fr yur particular truss type. ii. Vary the heights in regular increments ver a range that is reasnable. iii. Create a single graph that shws the Tensile Frces in Members vs. Height fr each f the members in tensin, including an apprpriate legend. (Yu d nt have t shw members that are identical due t symmetry.) This graph shuld be n a separate, named tab in the Truss Analyses wrkbk. d. Use the quantitative analysis and the material prperty graphs t determine (design) the height f yur truss. Add a cell fr each member frce that uses the best-fit equatins frm the tensile strength results t determine the necessary width f each member that is in tensin. 2. Cnstruct the truss/bridge using the specificatins in yur design. (Due at the end f class n Thursday, Nvember 17 th ) 3. Test the bridge and analyze hw it perfrms. (Bridges will be tested during class n Friday, Nvember 18 th ) Slid Edge Mdel 1. Create the part files necessary t have a cmplete slid mdel f yur designed bridge. (The creatin f these part files must be evenly distributed amng the grup members.) a. A single part file that will serve as the template fr the bars and gusset plates fr the designed truss b. Part files fr the tubes that are required fr the designed truss c. Part files fr the bttm and tp chrds that will cnnect the tw sides f the bridge d. Part files fr the lateral supprts that will cnnect the tps f the tw trusses (Due at the end f class n Wednesday, Nvember 9 th ) 2. Create an assembly f the designed truss. (Due at the end f class n Thursday, Nvember 17 th ) 3. Perfrm a finite element analysis f the designed truss. (Due at the end f class n Mnday, Nvember 28 th ) Written Reprt Cntent Requirements (Prfreader Dcumentatin x 2 due at the beginning f class n Thursday, December 1 st ) (Final Paper due by the end f schl n Friday, December 2 nd ) Each student is t submit a frmal written reprt that cnsists f the sectins listed belw in the rder shwn. Each member f the grup is t chse ne f the fur tpics n which t write Material Prperty Testing, Height Analysis, Manufacturing, r Finite Element Analysis. Abstract (specific t yur tpic) Intrductin & Backgrund

4 Briefly intrduce the prject as a whle Intrduce yur specific tpic and prvide apprpriate backgrund Intrduce the paper Methdlgy Material Prperty Testing discuss hw the tests were perfrmed Height Analysis discuss hw the Methd f Jints and Excel were used t select the height f yur truss Manufacturing discuss hw the trusses/bridges were manufactured and key issues assciated with the manufacturing prcess Finite Element Analysis discuss hw the bridge was mdeled in Slid Edge and hw the finite element analysis was perfrmed Results & Discussin Cnclusin Material Prperty Testing shw and discuss Tensile strength results The final bridge results (in the cntext f the material prperty testing) Height Analysis shw and discuss Key/sample results frm the Excel height analysis Final (graphical) truss design with member frces The final bridge results (in the cntext f the height analysis) Manufacturing shw and discuss Where the bridge ultimately failed Whether the failure f the bridge was a result f manufacturing errrs r material failure Hw the pint f failure cmpared with predictins frm the Finite Element Analysis Finite Element Analysis shw and discuss The slid mdel f the bridge Graphical utput frm the finite element analysis Key quantitative parameters and results frm the finite element analysis The final bridge results (in the cntext f the finite element analysis) What were the strengths and weaknesses f yur design? What qualitative and quantitative cnclusins can yu draw frm this prject? Hw culd this prject be imprved fr future classes? Written Reprt Frmatting Requirements The paper must adhere t the fllwing guidelines: Typeset using LaTeX 12 pint, Times New Rman fnt 1-inch margins n all sides 1.5 line spacing (with the exceptin f the title blck and abstract) and nt t exceed six pages, including the title page and figures

5 M. Cnner 5 EA2: Truss Design Assignment A title page that cntains the title, the curse, yur name (bld), the names f the thers in yur grup, the date, and the abstract A header n every page (but the title page) that has yur title in the upper, right crner A fter n every page (but the title page) that has yur last name in the lwer, left crner and the page number in the lwer, right crner At least ne anntated phtgraph in additin t ther figures Every figure and table must have an apprpriately placed and sufficiently detailed captins and be specifically referenced in the text (using the \ref cmmand in LaTeX). Oral Presentatin (PwerPint files due by the end f schl n Tuesday, December 6 th ) (Presentatins will be given n December 8 th and 9 th ) Each grup is t frmally present their wrk t the class as a grup. Each student s primary cntributin t the presentatin shuld mirrr the cntent f his r her written reprt. Each grup member is respnsible fr preparing the slides and presenting the infrmatin that g with his r her prtin f the presentatin. The frmat f the slides shuld be cnsistent with the Assertin-Evidence mdel that has been discussed in class. Each grup member will receive an individual grade fr their slides and fr their part f the presentatin. The presentatin must flw in terms f the cntent, the slide frmatting, and the transitins frm speaker t speaker. In rder t accmplish this, yu must cmmunicate well with the ther members f yur grup. Each grup member will als receive a grup grade fr the verall PwerPint and the verall presentatin. Grups with tw members will have 6 9 minutes fr their presentatins. Grups with three members will have 9 12 minutes fr their presentatins.

6 Warren Truss (Abutments at A & G; Lad 1 at C & E) Pratt (slid lines)/hwe (dashed lines) Truss (Abutments at A & H; Lad 1 at B & F; Lad 2 at D) Waddell Truss (Abutments at A & H; Lad 1 at B & F; Lad 2 at D)