b'FEATUREfor Waterloo, ON, was collected accordingly, and a Gumbel distribution is fitted to the data.While the Canadian W350s CVN toughness is 27 J at -20 C, the different subgrades of the European S355 do not all correspond to a 27 J CVN requirement, rendering a direct toughness comparison difficult. The non-27 J subgrades are converted to an equivalent 27 J, with an adjustment made to their test temperature using an equation developed in [3] to obtain a more direct comparison between the steels. Figure 2(a) shows the variation in the required CVN test temperature corresponding to the required steel grade/subgrade in the two designOur Business is Steelcodes for varying plate thickness.ThetoughnessrequirementsinCSAS6areindependentofOur Passion is Building Futuresplatethickness,asrepresentedbythehorizontalline,andare more conservative than the Eurocode for thinner plates (below 34 mm), resulting in a lower CVN test temperature requirement for 27 J. Both codes have the same toughness requirement in the middle range of plate thicknesses, and the Eurocode becomes more conservative for thicker plates (above 50 mm). Although this analysis is specific to a particular loading scenario for the CISC Straight Plate Girder Bridge Design Example 1 and the specificwww.tdsindustrial.comclimatic data for Waterloo, ON, the step function trend is similar for other European steel grades, such that toughness requirements forBuilding Futures is an initiative of TDS Industrial thicker plates are more rigorous.Services Ltd. In collaboration with International A second comparison is done for the entire span of the CISCNeeds Canada, to support & educate impoverished Design Example 1. While the first analysis is performed for a singlechildren around the world.location on the bridge (location of maximum positive stress), this secondanalysis(seeFigure2(b))looksatthechangesinsteelwww.internationalneeds.ca grade/subgraderequirementsusingtheEurocodewherethe stress level and plate thickness are both varying along the length of the bridge. Depending on the stresses and plate thickness, the toughnessSTRUCTURAL STEEL SPECIALISTSrequirement along the length of the bridge can vary significantly, based on this analysis using the Eurocode. This type of graph can help designers determine the toughness requirement to properly specify steel grade. Although the toughness requirement varies along the length, for ease of construction, it is generally preferable to use the same grade along the entire bridge. In this example case study, the pier is the location of maximum negative stress and governs the fracture toughness requirement for the entire bridge. It is observed that the locations of lower toughness requirement (JR) are generally near the inflection points. One possible use for this type of output might be to permit a lower toughness level at positions along the span other than the critical one for assessment purposes, such as assessing a point along the bridge span where a fatigue crack has been detected or the structure has been damagede.g. by vehicle impactor has a fatigue or CIF-prone detail present. Further work would be needed, however, to explore the value and potential pitfalls of using such an approach for assessment purposes. Other future work planned for this CISC-supported research project will include such things as comparing the results obtained so far with results obtained using the Eurocode fracture mechanics approach, as wellMoore Brothers Transport Ltd.asincorporatingreliabilityconsiderationsinthecomparisonof1834 Drew Road | Mississauga, ONL5S 1J6these various design approaches. It is expected that this work willTel: 905-673-6730 | Fax: 905-673-8680lead to proposals for possible improvements to the brittle fractureToll Free: 1-866-279-7907approach currently specified in CSA S6 or additional provisions forsmoore@moorebrothers.ca | www.moorebrothers.cause in bridge assessment. ASADVANTAGE STEEL SUMMER 2020|31'