Abstract: The term ‘Windphil Architecture’ refers to the building that facilitates natural ventilation by architectural elements. Natural ventilation uses the natural forces of wind pressure and stacks effect to direct the movement of air through buildings. Natural ventilation is increasingly being used in contemporary buildings to minimize the consumption of non-renewable energy and it is an effective way to improve indoor air quality. The main objective of this paper is to identify the strategies of using natural ventilation in Iranian modern buildings. In this regard, the research method is ‘descriptive-analytical’ that is based on comparative techniques. To simulate wind flow in the interior spaces of case studies, FLUENT software has been used. Research achievements show that it is possible to use natural ventilation to create a thermally comfortable indoor environment. The natural ventilation strategies could be classified into two groups of environmental characteristics such as public space structure, and architectural characteristics including building form and orientation, openings, central courtyards, wind catchers, roof, wall wings, semi-open spaces and the heat capacity of materials. Having investigated modern buildings of Iran, innovative elements like wind catchers and wall wings are less used than the traditional architecture. Instead, passive ventilation strategies have been more considered in the building design as for the roof structure and openings.
Abstract: Construction industry is making progress at a high pace. The trend of the world is getting more biased towards the high rise buildings. Deep beams are one of the most common elements in modern construction having small span to depth ratio. Deep beams are mostly used as transfer girders. This experimental study consists of 16 reinforced concrete (RC) deep beams. These beams were divided into two groups; A and B. Groups A and B consist of eight beams each, having 381 mm (15 in) and 457 mm (18 in) depth respectively. Each group was further subdivided into four sub groups each consisting of two identical beams. Each subgroup was comprised of solid/control beam (without opening), opening above neutral axis (NA), at NA and below NA. Except for control beams, all beams with openings were strengthened with carbon fibre reinforced polymer (CFRP) vertical strips. These eight groups differ from each other based on depth and location of openings. For testing sake, all beams have been loaded with two symmetrical point loads. All beams have been designed based on strut and tie model concept. The outcome of experimental investigation elaborates the difference in the shear behaviour of deep beams based on depth and location of circular openings variation. 457 mm (18 in) deep beam with openings above NA show the highest strength and 381 mm (15 in) deep beam with openings below NA show the least strength. CFRP sheets played a vital role in increasing the shear capacity of beams.
Abstract: Bridge piers often fail all over the world and the whole structure may be endangered due to scouring phenomena. Scouring has been linked to catastrophic failures that lead into the loss of human lives. Various techniques have been employed to extenuate the scouring process in order to assist the bridge designs. Pier modifications plays vital role to control scouring at the vicinity of the pier. This experimental study aims at monitoring the effectiveness of pier modification and temporal development of scour depth around a bridge pier by providing a collar, a cable or openings under the same flow conditions. Provision of a collar around the octagonal pier reduced more scour depth than that for other two configurations. Providing a collar around the octagonal pier found to be the best in reducing scour. The scour depth in front of pier was found to be 19.5% less than that at the octagonal pier without any modifications. Similarly, the scour depth around the octagonal pier having provision of a cable was less than that at pier with provision of openings. The scour depth around an octagonal pier was also compared with a plain circular pier and found to be 9.1% less.
Abstract: Topology optimization technique utilizes constant
element densities as design parameters. Finally, optimal distribution
contours of the material densities between voids (0) and solids (1) in
design domain represent the determination of topology. It means that
regions with element density values become occupied by solids in
design domain, while there are only void phases in regions where no
density values exist. Therefore the void regions of topology
optimization results provide design information to decide appropriate
depositions of web-opening in structure. Contrary to the basic
objective of the topology optimization technique which is to obtain
optimal topology of structures, this present study proposes a new idea
that topology optimization results can be also utilized for decision of
proper web-opening’s position. Numerical examples of linear
elastostatic structures demonstrate efficiency of methodological
design processes using topology optimization in order to determinate
the proper deposition of web-openings.
Abstract: Fragility analysis is an effective tool for the seismic vulnerability assessment of civil structures in the last several years. The design of the expansion joints according to various bridge design codes is almost inconsistent, and only a few studies have focused on this problem so far. In this study, the influence of the expansion joint clearances between the girder ends and the abutment backwalls on the seismic fragility assessment of continuous integral bridge frames is investigated. The gaps (ranging from 60 mm, 150 mm, 250 mm and 350 mm) are designed by following two different bridge design code specifications, namely, Caltrans and Eurocode 8-2. Five bridge models are analyzed and compared. The first bridge model serves as a reference. This model uses three-dimensional reinforced concrete fiber beam-column elements with simplified supports at both ends of the girder. The other four models also employ reinforced concrete fiber beam-column elements but include the abutment backfill stiffness and four different gap values. The nonlinear time history analysis is performed. The artificial ground motion sets, which have the peak ground accelerations (PGAs) ranging from 0.1 g to 1.0 g with an increment of 0.05 g, are taken as input. The soil-structure interaction and the P-Δ effects are also included in the analysis. The component fragility curves in terms of the curvature ductility demand to the capacity ratio of the piers and the displacement demand to the capacity ratio of the abutment sliding bearings are established and compared. The system fragility curves are then obtained by combining the component fragility curves. Our results show that in the component fragility analysis, the reference bridge model exhibits a severe vulnerability compared to that of other sophisticated bridge models for all damage states. In the system fragility analysis, the reference curves illustrate a smaller damage probability in the earlier PGA ranges for the first three damage states, they then show a higher fragility compared to other curves in the larger PGA levels. In the fourth damage state, the reference curve has the smallest vulnerability. In both the component and the system fragility analysis, the same trend is found that the bridge models with smaller clearances exhibit a smaller fragility compared to that with larger openings. However, the bridge model with a maximum clearance still induces a minimum pounding force effect.
Abstract: The floor beams of steel buildings, cold-formed steel
floor joists in particular, often require large web openings, which may
affect their shear capacities. A cost effective way to mitigate the
detrimental effects of such openings is to weld/fasten reinforcements.
A difficulty associated with an experimental investigation to establish
suitable reinforcement schemes for openings in shear zone is that
moment always coexists with the shear, and thus, it is impossible to
create pure shear state in experiments, resulting in moment
influenced results. However, Finite Element Method (FEM) based
analysis can be conveniently used to investigate the pure shear
behaviour of webs including webs with reinforced openings. This
paper presents the details associated with the finite element analysis
of thick/thin-plates (representing the web of hot-rolled steel beam,
and the web of a cold-formed steel member) having a large
reinforced opening. The study considered simply-supported
rectangular plates subjected to in-plane shear loadings until failure
(including post-buckling behaviour). The plate was modelled using
geometrically non-linear quadrilateral shell elements, and non-linear
stress-strain relationship based on experiments. Total Langrangian
with large displacement/small strain formulation was used for such
analyses. The model also considered the initial geometric
imperfections. This study considered three reinforcement schemes,
namely, flat, lip, and angle reinforcements. This paper discusses the
modelling considerations and presents the results associated with the
various reinforcement schemes under consideration.
Abstract: There are few studies on eggshell of leatherback turtle
which is endangered species in Thailand. This study was focusing on
the ultrastructure and elemental composition of leatherback turtle
eggshells collected from Andaman Sea Shore, Thailand during the
nesting season using scanning electron microscope (SEM). Three
eggshell layers of leatherback turtle; the outer cuticle layer or
calcareous layer, the middle layer or middle multistrata layer and the
inner fibrous layer were recognized. The outer calcareous layer was
thick and porosity which consisted of loose nodular units of various
crystal shapes and sizes. The loose attachment between these units
resulted in numerous spaces and openings. The middle layer was
compact thick with several multistrata and contained numerous
openings connecting to both outer cuticle layer and inner fibrous
layer. The inner fibrous layer was compact and thin, and composed of
numerous reticular fibers. Energy dispersive X-ray microanalysis
detector revealed energy spectrum of X-rays character emitted from
all elements on each layer. The percentages of all elements were
found in the following order: carbon (C) > oxygen (O) > calcium
(Ca) > sulfur (S) > potassium (K) > aluminum (Al) > iodine (I) >
silicon (Si) > chlorine (Cl) > sodium (Na) > fluorine (F) >
phosphorus (P) > magnesium (Mg). Each layer consisted of high
percentage of CaCO3 (approximately 98%) implying that it was
essential for turtle embryonic development. A significant difference
was found in the percentages of Ca and Mo in the 3layers. Moreover,
transition metal, metal and toxic non-metal contaminations were
found in leatherback turtle eggshell samples. These were palladium
(Pd), molybdenum (Mo), copper (Cu), aluminum (Al), lead (Pb), and
bromine (Br). The contamination elements were seen in the outer
layers except for Mo. All elements were readily observed and
mapped using Smiling program. X-ray images which mapped the
location of all elements were showed. Calcium containing in the
eggshell appeared in high contents and was widely distributing in
clusters of the outer cuticle layer to form CaCO3 structure. Moreover,
the accumulation of Na and Cl was observed to form NaCl which was
widely distributing in 3 eggshell layers. The results from this study
would be valuable on assessing the emergent success in this
endangered species.
Abstract: Chess is one of the indoor games, which improves the
level of human confidence, concentration, planning skills and
knowledge. The main objective of this paper is to help the chess
players to improve their chess openings using data mining
techniques. Budding Chess Players usually do practices by analyzing
various existing openings. When they analyze and correlate
thousands of openings it becomes tedious and complex for them. The
work done in this paper is to analyze the best lines of Blackmar-
Diemer Gambit(BDG) which opens with White D4... using data
mining analysis. It is carried out on the collection of winning games
by applying association rules. The first step of this analysis is
assigning variables to each different sequence moves. In the second
step, the sequence association rules were generated to calculate
support and confidence factor which help us to find the best
subsequence chess moves that may lead to winning position.