Usually, the heating, ventilation, and air conditioning (HVAC) duct system in buildings is a complex network of hollow metal pipes of rectangular or circular cross-section which behave as multimode waveguides when driven at RF and microwave frequencies of common interest. HVAC ducts can be used as a wireless communication channel for providing high-speed network access to offices [1]. An exampl...

Concrete filled cold-formed steel-concrete composite columns exhibit improved strength and ductility characteristics due to its ability resist inward buckling as well delay the outward buckling. Though concrete infill prevents buckling, still limits steel section from reaching yield strength. From past studies, it is observed that introducing of web stiffeners in cross-section may improve resis...

We study theoretically the propagation of elastic waves in two-dimensional composite media composed of a square array of hollow steel cylinders embedded in water using the finite-difference time-domain method. These composite media constitute a class of acoustic band gap materials with narrow pass bands in their transmission stop bands. The frequency at which the pass band occurs is tunable by ...

In recent years, rehabilitation has been the subject of extensive research due to increased spending on building work and repair of built works. In all cases, it is absolutely essential to carry out methods of strengthening or repair of structural elements, and that following an inspection analysis and methodology of a correct diagnosis. The reinforced concrete columns are important elements in...

Abstract Steel plate girders with I‐section are frequently used in industrial buildings and bridge design as prismatic members that means parallel flanges rectangular webs. The structural efficiency can significantly be achieved if such designed tapered webs non‐rectangular Depending on the flange inclination moment diagram, stress of is affected also known Résal effect. Furthermore, improved f...

<p>Steel arches are mostly built as rectangular hollow box sections. Most types of connection hangers to steel tied arch bridges require the introduction stiffeners, enabling transfer hanger force section’s webs. However, coincides with axis plane, whereas webs located in 2 vertical planes at a distance half width from axis. In particular case plates, connecting lower flange were also wel...

the effect of steel plate thickness on the repair effectiveness of rc beam is presented in this paper. a total of four beams were tested, one beam repaired by cfrp with a thickness of 1.2 mm and used as a control beam, and three beams repaired by a steel plate. steel plates with a thickness of 2 mm, 3 mm, and 4 mm were used in repairing the beams. the maximum load-carrying capacity, deflection ...

A Longitudinal opening is used to construct hollow core beam a cast in site or precast pre stressed concrete member with continuous voids provided reduce weight, cost and, as side benefit, use for concealed electrical mechanical runs. Primarily floor beams roof deck systems. This study investigate the behavior of six (solid opening) dimension (length 1000 x height 180 width120mm) simply support...