Design of composite beams with web openings
Summary Design techniques for composite beams with web openings have been under development for well over 30 years. During the past decade, these efforts have reached a level of maturity that allows for an accurate assessment of strength and the development of economical designs. This paper describes the behavior of steel}concrete composite beams with web openings and summarizes the key aspects of strength design and deflection calculation.
Cellular beam-columns in portal frame structures
Theoretical and numerical research into the application of cellular beam-column members in portal frame structures. Two failure mechanisms requiring additional research if cellular beams are to be applied as column members, have been investigated: 1) member flexural buckling, and 2) local web-post buckling. The flexural buckling behaviour of cellular columns has been shown to be similar to that of plain-webbed beams. A simplified design rule is proposed for checking the ultimate flexural buckling load capacity of cellular columns, and is shown to yield safe results. From an extensive parameter study an approximately linear relation between the web-post buckling capacity and an applied axial force has been shown to exist. Even although this influence is not effectively accounted for in the present available models for web-post buckling, these still turn out to be sufficiently conservative to be applied in column design. Results are applied to the design of a portal frame consisting entirely of cellular members, by means of a design tool developed in Microsoft Excel using VBA. This tool has been validated against 2D and 3D finite element analyses for different load cases using the finite element software SAFIR.
Self-assembly of pyridinium-tailored anthracene amphiphiles into supramolecular hydrogels.
The mixing of a polyacid cross-linker with a pyridinium-functionalized anthracene amphiphile afforded a supramolecular hydrogel through a self-assembly process that was primarily driven by π-stacking and electrostatic interactions.