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Designing a web panel for composite girders necessitates an accurate evaluation of the shear buckling strength. However, the current design specifications calculate the strength of web panels for composite girders conservatively. Additionally, its rational determination is missing in existing studies. This study investigates the shear buckling coefficients of composite girders through numerical analysis. The numerical analysis model assumes that the concrete slab fully restrains the web panel. In addition, the concrete slab of the composite girders in the numerical analysis model is replaced by equivalent top flange sections using a transformed thickness according to the modular ratio (n) of the concrete and steel. Additionally, the stiffness of the bottom flange and web panel is parameterized to evaluate the effect of their relative stiffness on the critical shear buckling strength of the web panel. The results show that the relative stiffness of the flange and web panel significantly affects the shear buckling coefficient. To determine the shear buckling coefficient by reflecting these structural characteristics, the relative stiffness is defined as the ratio of the torsional stiffness of the flange to the flexural stiffness of the web panel. The proposed formulas for the shear buckling coefficient of web panels for composite girders correlate well with the numerical analysis results. Since the accurate shear buckling strength can be derived from these formulas, the web panel for composite girders can be designed more accurately and economically. • Local buckling behavior of webs in composite plate girders was investigated based on finite element analysis. • Effects of flange and web stiffness ratio on web shear buckling in composite plate girders was evaluated. • Improved design equations of shear buckling coefficients in web shear buckling were proposed. • The proposed design equations shows a good correlation with FEA results when compared with equations in literature. [ABSTRACT FROM AUTHOR]

We report that the electrostatic association between a cyanovinylene (CV)-based cationic dye (CV–N+) and anionic surfactants rapidly induced the formation of self-assembled aggregates of CV-N+ molecules in an aqueous solution, displaying a red-shifted (Δλ = 100 nm), broad excimer emission at 650 nm. The anionic-surfactant-mediated excimer-forming properties of CV-N+ were further exploited as a versatile platform for the design of simple fluorescent "light-up" sensing systems for the specific and efficient detection of enzymatic activity (i.e., phospholipase D) and small molecules (i.e., bisulfite ions), respectively, without the complicated functionalization of fluorophores with suitable recognition groups. In these systems, which can be ensembled using various substrates, the cationic CV-N+ dye interacts with an anionic surfactant, which is the product of an analyte-induced specific reaction, thus triggering the formation of emissive aggregates. [ABSTRACT FROM AUTHOR]