b'FEATUREFIGURE 3:Weld fracturesfailure occurring by fracture along a plane throughthefilletweld.Severaltypical examples of weld fractures from the testing program are shown in Figure 3. Thestraingaugesinstalledonthe specimensadjacenttothewelds indicatednon-uniformloadingofthe branch(andhencetheweld),which (a)peakedaroundthesaddlepoints (seeFigure1b),and(b)wasmore pronounced in the specimens with high andslenderchords(i.e.highchord diameter-to-thickness, or D/t, ratios). FINITE ELEMENT MODELLINGNon-linear finite element (FE) models, withweldfracture,werevalidated against the results of the experimental tests, and an FE parametric study was performed to extend the test database. TheFEparametricstudyconsistedof 256CHS-to-CHSX-connections,with widervariationsin,D/t,andthe branchinclinationangle()compared to the experimental tests (namely 0.100.50, 10D/t50, 0.201.00, and6090).Theseparameters werekeptwithinthelimitsthatallow fillet welds, per AWS D1.1. As planned, all 256 of the FE connection models showed failure occurringagainby weld fracture. Throughthisexperimentaland FEresearch,itwasfoundthatfillet weldeffectivelengthsinCHS-to-CHS X-connections are (a) primarily a function of 2019 CISC and D/t and (b) become larger (relative to Collaboration Awardof Excellence the total weld length) asand D/t become smaller.Specifically,theweldeffective lengthsrangedfrom0.58to1.0times Spanning over 70 years, wethetotalweldlengthwithintheparameter continue to deliver engineeringrange studied, and welds in connections with excellence and a true spirit of collaboration with all of our(D/t) 8were100percenteffective.The partners. analyticallyobservedweld-effective-length trendsinCHS-to-CHSX-connections www.rjc.ca willbeprevalentinCHS-to-CHST-and Y-connections of similar geometries (under branch axial loading), and apply regardless 61 Avenue SW Pedestrian Bridge | Calgary, AB of weld type (e.g. fillet weld or partial joint VancouverVictoriaNanaimoKelownaCalgaryEdmontonLethbridgeTorontoOttawaKitchenerKingston penetrationgrooveweld)ifthewelds are designed to be fit for purpose. For 16|FALL 2019 ADVANTAGE STEEL'