Issue 9

Z.H. Qian et alii, Frattura ed Integrità Strutturale, 9 (2009) 105 - 112 ; DOI: 10.3221/IGF-ESIS.09.11 109 connection. Fig. 6 shows cracks in weld options at/near rib-to-diaphragm connections of the Williamsburg Bridge and the Bronx-Whitestone Bridge [18]. Based these investigations, the stresses at rib-to-diaphragm connections (without bulkhead) under different loadcases to diverse shapes of cutout were studied [19] . The numerical analysis clearly demonstrated that different load locations influence the stress status of diaphragm greatly, and peak stresses occur at the rib-to-diaphragm connections or rib-to- diaphragm-deck plate (RDDP) connections, see Fig. 7. Figure 5 : FE model of submodel analysis (Kiss, 2002). Figure 6 : Cracks in weld options at near rib-to-diaphragm connection (Tsakopoulos, 2005). Figure 7 : Stress distribution at diaphragm (Abruzzese et al., 2008). R IB - TO - DIAPHRAGM - TO - DECK PLATE ( RDDP ) CONNECTION n recent, rib-to-diaphragm-to-deck plate connection is found to be another sensitive place to produce fatigue cracking [10, 20]. Based on the numerical analysis, it is found that peak stresses are produced at RDDP connections, and as well the out-of-plane stress should be considered to the fatigue design. I