scholarly journals Joint Layout Design: Finding the Strongest Connections within Segmental Masonry Arched Forms

2022 ◽  
Vol 7 (1) ◽  
pp. 9
Author(s):  
Elham Mousavian ◽  
Claudia Casapulla

Segmental arched forms composed of discrete units are among the most common construction systems, ranging from historic masonry vaults to contemporary precast concrete shells. Simple fabrication, transport, and assembly have particularly made these structural systems convenient choices to construct infrastructures such as bridges in challenging environmental conditions. The most important drawback of segmental vaults is basically the poor mechanical behaviour at the joints connecting their constituent segments. The influence of the joint shape and location on structural performances has been widely explored in the literature, including studies on different stereotomy, bond patterns, and interlocking joint shapes. To date, however, a few methods have been developed to design optimal joint layouts, but they are limited to extremely limited geometric parameters and material properties. To remedy this, this paper presents a novel method to design the strongest joint layout in 2D arched structures while allowing joints to take on a range of diverse shapes. To do so, a masonry arched form is represented as a layout of potential joints, and the optimization problems developed based on the two plastic methods of classic limit analysis and discontinuity layout optimization find the joint layout that corresponds to the maximum load-bearing capacity.

2015 ◽  
Vol 25 (6) ◽  
pp. 870-908 ◽  
Author(s):  
NIKOLAOS FOUNTOULAKIS ◽  
MEGHA KHOSLA ◽  
KONSTANTINOS PANAGIOTOU

Ak-uniform hypergraphH= (V, E) is called ℓ-orientable if there is an assignment of each edgee∈Eto one of its verticesv∈esuch that no vertex is assigned more than ℓ edges. LetHn,m,kbe a hypergraph, drawn uniformly at random from the set of allk-uniform hypergraphs withnvertices andmedges. In this paper we establish the threshold for the ℓ-orientability ofHn,m,kfor allk⩾ 3 and ℓ ⩾ 2, that is, we determine a critical quantityc*k,ℓsuch that with probability 1 −o(1) the graphHn,cn,khas an ℓ-orientation ifc<c*k,ℓ, but fails to do so ifc>c*k,ℓ.Our result has various applications, including sharp load thresholds for cuckoo hashing, load balancing with guaranteed maximum load, and massive parallel access to hard disk arrays.


2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Ji-Hun Kim ◽  
Won-Kee Hong ◽  
Hee-Cheul Kim ◽  
Seong-Kyum Kim

This study aims to evaluate flexural strength based on the inelastic neutral axis calculated from all stress states of the proposed precast composite columns with hybrid beam-column joints, which facilitate the erection of concrete precast frames in a similar manner to that used for steel frames. It was also shown analytically that hybrid joints with headed studs contribute significantly to the flexural moment capacity and effectively increase the flexural structural performance of precast composite columns. The strain compatibility-based analytical results were compared with test data, showing results with an error of less than 8% at the critical section for the maximum load limit state of specimens. It is observed that the strength contributed by steel sections and headed studs increased by 30% and 35% at the yield limit state and maximum load limit, respectively, reducing the dependence on rebars. The total contribution of the headed studs was as large as 12.2% (average of the two layers of headed studs) at the maximum load limit state, whereas the strength provided by the tensile rebars decreased from 90.5% to 63.9% for the specimen with headed studs at the maximum load limit state.


2014 ◽  
Vol 644-650 ◽  
pp. 2169-2172
Author(s):  
Zhi Kong ◽  
Guo Dong Zhang ◽  
Li Fu Wang

This paper develops an improved novel global harmony search (INGHS) algorithm for solving optimization problems. INGHS employs a novel method for generating new solution vectors that enhances accuracy and convergence rate of novel global harmony search (NGHS) algorithm. Simulations for five benchmark test functions show that INGHS possesses better ability to find the global optimum than that of harmony search (HS) algorithm. Compared with NGHS and HS, INGHS is better in terms of robustness and efficiency.


2012 ◽  
Vol 239-240 ◽  
pp. 1027-1032 ◽  
Author(s):  
Qing Guo Wei ◽  
Yan Mei Wang ◽  
Zong Wu Lu

Applying many electrodes is undesirable for real-life brain-computer interface (BCI) application since the recording preparation can be troublesome and time-consuming. Multi-objective particle swarm optimization (MOPSO) has been widely utilized to solve multi-objective optimization problems and thus can be employed for channel selection. This paper presented a novel method named cultural-based MOPSO (CMOPSO) for channel selection in motor imagery based BCI. The CMOPSO method introduces a cultural framework to adapt the personalized flight parameters of the mutated particles. A comparison between the proposed algorithm and typical L1-norm algorithm was conducted, and the results showed that the proposed approach is more effective in selecting a smaller subset of channels while maintaining the classification accuracy unreduced.


2019 ◽  
Vol 3 (1) ◽  
pp. 7
Author(s):  
Fanny Monika ◽  
Hakas Prayuda ◽  
Al Fajir M Sarita

<p class="Abstract"><em>The behavior of precast concrete beams can be seen in the magnitude of the value of maximum load, deflection, moment and curvature. To facilitate analyzing these parameters using the Response-2000 software. The software is used to analyze beams with evenly distributed loads. The output of the application is in the form of deflection values, maximum load, and moment of curvature. This research was carried out by varying the dimensions of the beam and the position of the flexural reinforcement with a span length of 10 m. BU3 beam with a height of 1000 mm, width 150 mm, upper wing height 160 mm, lower wing height 150 mm upper wing width 300 mm and lower wing height 450 mm has a deflection of at least -95,248 mm and BU6 beam with a height of 1080 mm, width 152 mm, wing height 100 mm, wing height 130 mm, wingspan 381 mm and wing width 508 mm having a deflection of at most -114,471 mm. BU2 beam with a height1000 mm, width 150 mm, upper wing height 240 mm, wing height 150 mm, wingspan 300 mm and wingspan 450 mm has the smallest maximum load 81,265 kN/m and BU6 beam has maximum load 93,224 kN/m. BU2 beam has the smallest nominal moment of 1821,036 kNm and BU6 beam has the largest nominal moment value of 2093,920 kNm</em></p>


2021 ◽  
Vol 1197 (1) ◽  
pp. 012062
Author(s):  
Aman Agrawal ◽  
S.S. Sanghai ◽  
Kuldeep Dabhekar

Abstract In India, greatest constructional exercises are finished utilizing the old convectional cast in situ strategies since seemingly forever. As the nation is creating in a high speed, the necessity for lodging is heightening and in this way the development ventures are additionally blossoming quickly henceforth requesting quicker and better development techniques. This expanded interest can be coordinated by utilizing one of the cutting-edge innovations, pre-projected substantial strategy. Investigation of writing shows various priority of precast constructional strategy over different techniques for development. Appropriately, this investigation presents the examination and plan of g+5 floor precast concrete structure and traditional cast-in-situ structure. The designs were demonstrated and investigated utilizing Etabs programming for dead, forced, and seismic loads and for load combinations. The fundamental intention was to consider the conduct of both the sorts of structures under the previously mentioned loads and load mixes. Examination was directed dependent on different components like external loads, greatest deflections, most extreme story drifts, mode shapes, time-frames, frequencies and base shears.


Author(s):  
C. Tuna ◽  
F. Merciol ◽  
S. Lefèvre

Abstract. Monitoring observable processes in Satellite Image Time Series (SITS) is one of the crucial way to understand dynamics of our planet that is facing unexpected behaviors due to climate change. In this paper, we propose a novel method to assess the evolution of objects (and especially their surface) through time. To do so, we first build a space-time tree representation of image time series. The so-called space-time tree is a hierarchical representation of an image sequences into a nested set of nodes characterizing the observed regions at multiple spatial and temporal scales. Then, we measure for each node the spatial area occupied at each time sample, and we focus on its evolution through time. We thus define the spatio-temporal stability of each node. We use this attribute to identify and measure changing areas in a remotely-sensed scene. We illustrate the purpose of our method with some experiments in a coastal environment using Sentinel-2 images, and in a flood occurred area with Sentinel-1 images.


Cliometrica ◽  
2021 ◽  
Author(s):  
Toke S. Aidt ◽  
Stanley L. Winer ◽  
Peng Zhang

AbstractThe Redistribution Hypothesis predicts that franchise extension causes an increase in state-sponsored redistribution. We test this hypothesis by considering the relationship between franchise extension and selected aspects of fiscal structure at both central and local government levels in the UK from 1820 to 1913. We do so without imposing a priori restrictions on the direction of causality using a novel method for causal investigation of non-experimental data proposed by Hoover (2001). This method is based on tests for structural breaks in the conditional and marginal distributions of the franchise and fiscal structure time series preceded by a detailed historical narrative analysis. We do not find compelling evidence supporting the Redistribution Hypothesis.


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