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54After the initial test was completed, the sample was then tested until failure. Thiswas done with the amount of stroke movement in the MTS machine being controlled.This means that the amount of strain placed on the sample was controlled rather than theamount of load that was placed on the sample. The testing coupon was first pulled at arate of 1/32 inch per minute until after the yielding, and was then stretched 1/8 inch perminute in the plastic region until failure. As in the initial test, the readings from the straingages, extensometer, load cell and stroke control were recorded using the Strain Smartsoftware. Once the test was completed, measurements were taken of the eye hole using amicrometer parallel and perpendicular to the direction of loading. This was done todetermine the amount of elongation of the hole in the connection.From the initial test, the data collected were the linear strains that occurred duringthe elastic testing. The strains that occurred for all ten gages were then depicted on thesame plot so that they could be compared to each other. From this plot it can be seenwhere the stresses are greater on the eye connection. A plot of the strains that occurred atthe various strain gages for one eyebar connection test can be seen in Figure 3.24. Thisdata was then compared to the results generated from the ANSYS computer model of theeye connection. The second test to full failure was completed to see if the connectionwould fail in the eye detail or in the shank.3.9 Eyebar Connection Testing with Filler WeldA common problem that occurs when repairing historic iron truss bridges isexcessive corrosion of these eyebar end connections. Often it is too costly to replace theentire eyebar, so a less expensive repair method is preferred. Therefore, along withinvestigating the behavior of a typical eyebar end connection, the behavior of a damagedand repaired eyebar end connection was also investigated. One repair method that wasinvestigated during this study was filling the corroded area of the eyebar with weldmaterial to reduce the loss of section. Two eyebar end connections were tested in tension
55using the 220-kip servo hydraulic MTS testing machine in the Kettelhut StructuralEngineering Laboratory, each with different patterns of corrosion and repair modeled.The first eyebar connection, Eyebar A had material removed to simulate acommon corrosion pattern found on the lower chord eyebars of historic iron truss bridges.In this pattern, excessive corrosion was typically prevalent in an arched area on thebottom edge of one surface of an eyebar end connection. This corrosion is most likely theresult of condensation that collects at the edge on one side of a bottom chord eyebarmember. Figure 3.25 is a picture of Eyebar A, after some of the material was removed tomodel this corrosion pattern. Half of the thickness of the original eyebar was removed inthe area of which the eyebar was machined to resemble corrosion.Once this material was removed, the area simulating corrosion needed to be filledwith weld material. To do this an E7024 SMAW 1/8” diameter welding rod was utilizedwith a DC reverse polarity electric source. The welding rod used is only permitted forwelding in the flat and horizontal direction but is a very good filler welding rod andreduces the number of passes needed to fill the area.Welding passes were added in the long direction of the treated area to reduce heatdistortion in the eyebar. The initial root pass was placed in the far corner of the area thatwas removed with the bar lying flat on a surface. Figure 3.26 shows the eyebar after theinitial pass had been placed, and illustrates the direction in which the welds weredeposited.Additional weld passes were added first along the base of the removed sectionand then on top of the previous welds using the same procedure between passes. Thisprocedure consisted of checking the temperature of the metal to ensure that it had notexceeded approximately 280 deg F to ensure that the filler weld would not be too fluidand the metal to hot to weld. The weld was also cleaned with a chisel hammer and wirebrush. Figure 3.27 shows the eyebar end connection after the filler welding was
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Purdue UniversityPurdue e-PubsJTRP
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1. Report No. 2. Government Accessi
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epairing a bent wrought iron tensio
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vPageCHAPTER 3TEST PROCEDURES FOR M
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ixLIST OF FIGURESFigurePageFigure 1
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xiFigurePageFigure 3.30 Top View of
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xiiiFigurePageFigure 5.12 Typical T
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xvAppendix FigurePageFigure D.7 Ini
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viiiAppendix TablePageTable A.5 Det
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iiiThe authors would also like to t
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2but also what material properties
Page 24 and 25: 4microstructure of the metal. The c
Page 26 and 27: 62. LITERATURE SEARCHBefore experim
Page 28 and 29: 8imperfections, the performance of
Page 30 and 31: 10wrought iron. Adding the slag aft
Page 32 and 33: 12method for manufacturing wrought
Page 34 and 35: 14patents for their process and tra
Page 36 and 37: 16This method of testing of structu
Page 38 and 39: 18plot of this percent elongation d
Page 40 and 41: 20significant variation in the perc
Page 42 and 43: 22The practice of restoring histori
Page 44 and 45: 24Elleby, Wallace W. Sanders, F. Wa
Page 46 and 47: 26From all the surveys that were di
Page 48 and 49: 28Table 2.1 Average Ultimate Streng
Page 50 and 51: 30Figure 2.3 Wrought Iron “Sponge
Page 52 and 53: 32Histogram of Kirkaldy Wrought Iro
Page 54 and 55: 34Percent Occurance in Range - %45.
Page 56 and 57: 3660Combined Wrought Iron BarsTensi
Page 58 and 59: 38The Bell Ford Bridge consisted of
Page 60 and 61: 40Two. These samples were taken fro
Page 62 and 63: 42specimens were of constant cross
Page 64 and 65: 44Along with rectangular tensile co
Page 66 and 67: 46After the initial test loading wa
Page 68 and 69: 483.6 Fatigue TestingTo develop a b
Page 70 and 71: 50The final specimen category consi
Page 72 and 73: 52This analysis was completed using
Page 76 and 77: 56completed, but before the surface
Page 78 and 79: 58readings, load cell readings and
Page 80 and 81: 60Figure 3.3 Donated Eyebars 4 and
Page 82 and 83: 62Figure 3.7 Heated Areas in Blue o
Page 84 and 85: 64Figure 3.11 Detail Used in Groove
Page 86 and 87: 66900080007000y = 27.153xR 2 = 0.99
Page 88 and 89: 68Figure 3.19 Charpy Impact Testing
Page 90 and 91: 70Figure 3.23 Eyebar Connection in
Page 92 and 93: 72Figure 3.27 Eyebar A After Filler
Page 94 and 95: 74Figure 3.31 Side View of Finished
Page 96 and 97: 76Figure 3.35 Front View of Eyebar
Page 98 and 99: 78strength from the existence of pe
Page 100 and 101: 80The carbon content present in the
Page 102 and 103: 82value may not be very accurate bu
Page 104 and 105: 84strengths was found to be 29,940
Page 106 and 107: 86wrought iron bars were investigat
Page 108 and 109: 88stresses are induced. These perma
Page 110 and 111: 90toughness the material. The test
Page 112 and 113: 92From the finite element analysis,
Page 114 and 115: 94Table 4.1 Chemical Analysis of Ey
Page 116 and 117: 96Table 4.3 Tensile Coupon Test Res
Page 118 and 119: 98Table 4.5 Charpy Impact Test Resu
Page 120 and 121: 100Table 4.7 Comparison of Strain G
Page 122 and 123: 102Figure 4.1 Typical Micrograph of
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104Figure 4.5 Fracture Surface of D
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106Comparison of Tensile Strengthfo
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108Combined Wrought Iron Bar Histor
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110Figure 4.17 Macrograph of Weld u
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112Figure 4.21 Cleavage Fracture of
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Figure 4.25 Elongation of Hole in E
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116signs on or near the bridge that
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118testing of historic wrought iron
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120so that they would act in symmet
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122The reasons for the differences
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124The second corrosion pattern mod
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126Keating (1984) stated that the s
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128charcoal fire until it is red ho
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130Figure 5.3 Picture of Bottom Cho
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132Figure 5.7 Using Force After Usi
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134Figure 5.11 Reassembling a Pin C
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1366. SUMMARY, CONCLUSIONS AND IMPL
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138rectangular in shape. These eyeb
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140were joined together with a full
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1424. The Charpy impact energy of t
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144connections are unsymmetrical, i
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146LIST OF REFERENCESAASHTO (1998).
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148Hodgkinson, Eaton (1840). Experi
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150Appendix A. Data Collected From
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152Table A.1 Wrought Iron Bar Tensi
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154Table A.1 (continued) Wrought Ir
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156Table A.2 (continued) Wrought Ir
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158Table A.3 Wrought Iron Angle Ten
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160Table A.4 (continued) Summary of
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162Table A.4 (continued) Summary of
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164Table A.5 (continued) Detailed I
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184Table A.7 Tensile Strength Data
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186Table B.1 Example Historic Wroug
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188DepartmentofTransportationIf you
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190CountyIf your organizationdoes m
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192County 16: County bridge inspect
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194State 13: Included in original d
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196Figure C.1 Diagrams Showing Loca
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198Figure C.3 Heating of Eyebar fro
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200Figure C.7 Double V Butt Joint u
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202Figure C. 11 Welded Tensile Coup
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204Figure C.15 Tensile Coupon from
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206Figure C.19 Cooling Bath with Su
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208Figure C.23 Side View of Eyebar
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210Figure C.27 Eyebar End Connectio
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212Appendix D. Welding Procedure fo
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214D.2 Filler Weld for Eyebar Conne
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216Figure D.1 Weld Joint Detail Use
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Figure D.5 Completed Weld Before Su
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220Figure D.7 Initial Pass Pattern
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