As notch stress can effectively reflect the influence of welding geometry on local stress concentration, it can be used for fatigue strength evaluation of complex welded joints. In order to avoid stress singularity effect caused by the corner, virtual radius is introduced into fatigue evaluation of welded structures. However, the virtual radius recommended by the current specifications is only for steel and aluminum alloy materials, and is not applicable for thin-plate structures, especially for welded structures of special alloy materials and dissimilar materials. Considering the influence of alloy materials and size effect on hypothetical virtual notch stress, based on effective notch stress theory and finite element method, the optimal virtual radius values suitable for thin-plate alloy welded structures are proposed and verified respectively. After optimizing the virtual radius, the scatter band index of the notch stress S–N curve is significantly lower than the result of nominal stress.

Effective notch stress method for fatigue assessment of sheet alloy material and bi-material welded joints

Fatigue strength assessment of ultra-high-strength steel fillet weld joints using 4R method

UHPC-based strengthening technique for orthotropic steel decks with significant fatigue cracking issues

Based on cracking inspection on an orthotropic steel bridge, stress behaviors and fatigue life at cutout detail are investigated through field measurement and multi-level FEM modelling. Research finds that fatigue cracks at cutout detail are highly related to wheel path. Biaxial compression at cutout detail implies high residual stress and it suffers severe out-of-plane distortion. Fatigue life can be evaluated based on category B with stress location 5 mm away from free edge of cutout. It is concluded that serious overweight trucks, significant stress concentration, too thin diaphragms, and poor finish condition jointly contribute to early cracking at cutout detail.

Fatigue damage investigation on diaphragm cutout detail on orthotropic bridge deck based on field measurement and FEM

Full-Scale Experimental Investigation of the Fatigue Property of Welded Single- and Double-sided Deck-U Rib Joints in OBD

An equivalent structural stress-based fatigue evaluation framework for rib-to-deck welded joints in orthotropic steel deck

Protective effect of railway bridge wind barriers on moving trains: An experimental study

The drive-by method has become a popular indirect approach for bridge damage inspection (BDI) because of its simplicity in deployment by evaluating the bridge health status solely via the vehicle dynamic response. Derived from the vehicle dynamic response, the recent proposed contact-point response involves no vibration signal with the vehicle frequency, bearing great potential for drive-by BDI. However, an appropriate methodology for the application of contact-point response in drive-by BDI remains lacking. The present study proposes a novel drive-by method, in which a new damage factor index, i.e., the characteristic wavelet coefficient (CWC), is established for bridge damage identification in an efficient and accurate manner. The CWC is obtained by analyzing the contact-point response via the continuous wavelet transform (CWT) and complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN) techniques. CEEMDAN is introduced to overcome the issue of modal aliasing and pseudo-frequency. First, the general framework of the proposed drive-by BDI method is introduced. Then, a demonstration case study is carried out to examine the effectiveness of the proposed method. Subsequently, a parametric study is carried out to explore the effects of several parameters on the performance of BDI including the scale factor, vehicle speed, environmental noise, and boundary effect. The results indicate that the proposed drive-by BDI method can better eliminate the mode mixing and pseudo-frequency problems during the extraction of the CWC, compared with the traditional ensemble empirical mode decomposition method. The extracted CWC curve is smooth, convenient for damage inspection, and has strong anti-noise performance. After adding white noise with a signal-to-noise ratio of 20, a bridge girder with a damage severity of 20% can be identified successfully. In addition, the selection of the scale factor is critical for bridge damage inspection based on the extracted CWC. The effective scale factor of the CWC extracted using the proposed method has a wide range, which improves the inspection efficiency. Finally, a low vehicle speed is beneficial to alleviate the adverse effect of the boundary effect on the damage inspection of bridge girder ends.

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A New Drive-by Method for Bridge Damage Inspection Based on Characteristic Wavelet Coefficient

The invention discloses a steel-Concrete composite bridge structure and composite bridge deck. This steel-concrete composite bridge structure comprises a composite bridge deck and a supporting beam structure supporting the connecting bridge deck. The composite bridge deck comprises a corrugated steel top plate, a reinforcing bar structure arranged on the upper part of the corrugated steel top plate and a concrete structure poured on the corrugated steel top plate and the reinforcing bar structure and connected with the corrugated steel top plate through a connecting piece. The concrete composite bridge deck comprises a corrugated steel top plate, a reinforcing bar structure arranged on the corrugated steel top plate and the corrugated steel top plate. limit bending resistance is obviouslyimproved, the cost is reduced and the dead weight is reduced at the same time.

Jinzhu Zhu

Papers

An equivalent structural stress-based fatigue evaluation framework for rib-to-deck welded joints in orthotropic steel deck

Protective effect of railway bridge wind barriers on moving trains: An experimental study

A New Drive-by Method for Bridge Damage Inspection Based on Characteristic Wavelet Coefficient

Steel-concrete composite bridge structure and composite bridge deck

Fatigue performance of rib-to-deck joints in orthotropic steel deck with PWHT