Analytical study of lipped cold-formed steel sections with edge-stiffened hole subjected to axial compression load

Cold-formed steel (CFS) have been widely used in different structural systems in residential and non-residential construction, especially roof structures due to many advantages. Firstly, no heat is used to form the sections unlike hot-rolled steel. Secondly, several steel thicknesses are offered to accommodate a wide range of structural and non-structural purposes. Researchers have recently searched in the usage of CFS sections, and their research showed an improvement in stiffness and strength of these sections. Therefore, the purpose of this search is to analyze and conduct the behaviour of lipped single and double channel back-to-back CFS sections with edge-stiffened hole. The built-up section attached with self-taping screws under axial compression load. The main focus of this search is to enhance comprehension of the axial behaviour of the simply supported lipped CFS channel sections by analyzing and conducting the behaviour of pinned end condition CFS columns under the effect of static displacement loading till failure and to conduct the verification of the previous finite element modelling. Additionally, this research, focus on determining how the properties of section affect the behaviour and axial strength of lipped CFS column sections and to develop the fundamental parameters and the numerical criteria needed for the non-linear analysis to model lipped CFS column sections

The Performance of Cold-Formed Steel Members with Stiffened Perforations

CFS sections are usually supplied with openings to adapt construction services. Nevertheless, the area lowering in the web influences their strengths. If stiffeners are provided near the web openings, the reduction in flexural capacity could be recovered. Therefore, this paper introduces a study on the CFS section with stiffened perforations. A finite element (FE) analysis was accomplished. The numerical model was verified versus experimental and numerical tests from prior research and then utilized in performing parametric studies. The influence of circular openings with various sizes and various stiffener lengths on the flexural capacity was examined in the nonlinear analysis. Depending on the findings of the study, it has been determined that the introduction of stiffened openings into the CFS members will result in the restoration of the original flexural capacity

Effect of Web Opening Location on Fatigue Assessment of H Section Steel Beams

In the last decades, steel beams with web opening were used extensively as useful structural and architectural elements due to their many advantages. In this research, steel beams with web opening subjected to static loading were modelled using the multi-purpose finite element software ANSYS and the finite element results were compared with previous research. Then, steel beams with a single web opening subjected to fatigue loading were investigated numerically. The effect of changing the location of web opening on the fatigue assessment of H section steel beams with web opening was studied taking normal stress into account. It was clear that, normal stress fatigue life of the steel beams was affected significantly by changing web opening location along the beam span when compared to a beam with solid web while the beam span, opening size and steel section were kept constant. The most convenient location of web opening along the beam span was found to be at mid span

Classical and quantum partition bound and detector inefficiency

We study randomized and quantum efficiency lower bounds in communication complexity. These arise from the study of zero-communication protocols in which players are allowed to abort. Our scenario is inspired by the physics setup of Bell experiments, where two players share a predefined entangled state but are not allowed to communicate. Each is given a measurement as input, which they perform on their share of the system. The outcomes of the measurements should follow a distribution predicted by quantum mechanics; however, in practice, the detectors may fail to produce an output in some of the runs. The efficiency of the experiment is the probability that the experiment succeeds (neither of the detectors fails). When the players share a quantum state, this gives rise to a new bound on quantum communication complexity (eff*) that subsumes the factorization norm. When players share randomness instead of a quantum state, the efficiency bound (eff), coincides with the partition bound of Jain and Klauck. This is one of the strongest lower bounds known for randomized communication complexity, which subsumes all the known combinatorial and algebraic methods including the rectangle (corruption) bound, the factorization norm, and discrepancy. The lower bound is formulated as a convex optimization problem. In practice, the dual form is more feasible to use, and we show that it amounts to constructing an explicit Bell inequality (for eff) or Tsirelson inequality (for eff*). We give an example of a quantum distribution where the violation can be exponentially bigger than the previously studied class of normalized Bell inequalities. For one-way communication, we show that the quantum one-way partition bound is tight for classical communication with shared entanglement up to arbitrarily small error.Comment: 21 pages, extended versio

Adversary lower bounds for nonadaptive quantum algorithms

International audienceWe present general methods for proving lower bounds on the query complexity of nonadaptive quantum algorithms. Our results are based on the adversary method of Ambainis

Priority diffusion model in lattices and complex networks

We introduce a model for diffusion of two classes of particles ($A$ and $B$) with priority: where both species are present in the same site the motion of $A$'s takes precedence over that of $B$'s. This describes realistic situations in wireless and communication networks. In regular lattices the diffusion of the two species is normal but the $B$ particles are significantly slower, due to the presence of the $A$ particles. From the fraction of sites where the $B$ particles can move freely, which we compute analytically, we derive the diffusion coefficients of the two species. In heterogeneous networks the fraction of sites where $B$ is free decreases exponentially with the degree of the sites. This, coupled with accumulation of particles in high-degree nodes leads to trapping of the low priority particles in scale-free networks.Comment: 5 pages, 3 figure

Assessment of the potential forecasting skill of a global hydrological model in reproducing the occurrence of monthly flow extremes

As an initial step in assessing the prospect of using global hydrological models (GHMs) for hydrological forecasting, this study investigates the skill of the GHM PCR-GLOBWB in reproducing the occurrence of past extremes in monthly discharge on a global scale. Global terrestrial hydrology from 1958 until 2001 is simulated by forcing PCR-GLOBWB with daily meteorological data obtained by downscaling the CRU dataset to daily fields using the ERA-40 reanalysis. Simulated discharge values are compared with observed monthly streamflow records for a selection of 20 large river basins that represent all continents and a wide range of climatic zones. <br><br> We assess model skill in three ways all of which contribute different information on the potential forecasting skill of a GHM. First, the general skill of the model in reproducing hydrographs is evaluated. Second, model skill in reproducing significantly higher and lower flows than the monthly normals is assessed in terms of skill scores used for forecasts of categorical events. Third, model skill in reproducing flood and drought events is assessed by constructing binary contingency tables for floods and droughts for each basin. The skill is then compared to that of a simple estimation of discharge from the water balance (<i>P</i>−<i>E</i>). <br><br> The results show that the model has skill in all three types of assessments. After bias correction the model skill in simulating hydrographs is improved considerably. For most basins it is higher than that of the climatology. The skill is highest in reproducing monthly anomalies. The model also has skill in reproducing floods and droughts, with a markedly higher skill in floods. The model skill far exceeds that of the water balance estimate. We conclude that the prospect for using PCR-GLOBWB for monthly and seasonal forecasting of the occurrence of hydrological extremes is positive. We argue that this conclusion applies equally to other similar GHMs and LSMs, which may show sufficient skill to forecast the occurrence of monthly flow extremes