Frequency: Quarterly E- ISSN: 2230-8164 P- ISSN: 2249-1341 Abstracted/ Indexed in: Ulrich's International Periodical Directory, Google Scholar, SCIRUS, Genamics JournalSeek, EBSCO Information Services
Quarterly published in print and online "Inventi Impact: Structure & Design" publishes high quality unpublished as well as high impact pre-published research and reviews catering to the needs of researchers and professionals. This journal deals with all the aspects of structures and designs with particular emphasis on: infrastructure engineering, earthquake engineering, structure-fluid-soil interaction, wind engineering, fire engineering, blast engineering, structural reliability/stability, life assessment/integrity, structural health monitoring, multi-hazard engineering, structural dynamics, optimization, expert systems, experimental modelling, performance-based design, multiscale analysis, value engineering etc. Papers are especially encouraged in topics such as tall buildings, innovative structures, environmentally responsive structures, bridges, stadiums, commercial and public buildings, transmission towers, television and telecommunication masts, cooling towers, plates and shells, suspension structures, smart structures, nuclear reactors, dams, pressure vessels, pipelines, tunnels etc.
Electromagnetic bandgap (EBG) structures can help in the reduction of mutual coupling by their capabilities of suppressing surface wave's propagation in a specific frequency range. In this work, a dual-layer EBG structure, which had a lower resonant frequency than the single-layer one, is proposed in order to reduce the mutual coupling between E-plane coupled microstrip antenna array. As this EBG structure significantly made the series capacitance between neighbor cells larger, a drastic reduction of the unit cell size was achieved. The simulated and experimental results show that the proposed structure has a significant 19?dB mutual coupling reduction....
Recompression supercritical carbon dioxide (SCO2) Brayton Cycle for the Chinese Initiative Accelerator Driven System (CiADS)\nis taken into account, and flexible thermodynamic modeling method is presented. The influences of the key parameters on\nthermodynamic properties of SCO2 Brayton Cycle are discussed and the comparative analyses on genetic algorithm and pattern\nsearch algorithm are conducted. It is shown that the cycle parameters such as turbine inlet temperature, pressure ratio, outlet\ntemperature at the hot end of condenser, and terminal temperature difference of regenerator 1 and regenerator 2 have significant\neffects on the cycle thermal efficiency. The calculation results indicate that pattern search algorithm has better optimization\nperformance and quicker calculating speed than genetic algorithm. The result of optimization of the parameters for CiADS with\nsupercritical carbon dioxide Brayton Cycle is 35.97%. Compared with other nuclear power plants of SCO2 Brayton Cycle, CiADS\nwith SCO2 Brayton Cycle does not have the best thermal efficiency, but the thermal efficiency can be improved with the reactor\noutlet temperature increases....
The Moment Distribution Method is a quite powerful hand method of structural analysis, in which the solution is obtained\niteratively without even formulating the equations for the unknowns. It was formulated by Professor Cross in an era where\ncomputer facilities were not available to solve frame problems that normally require the solution of simultaneous algebraic\nequations. Its relevance today, in the era of personal computers, is in its insight on how a structure reacts to applied loads by\nrotating its nodes and thus distributing the loads in the form of member-end moments. Such an insight is the foundation of the\nmodern displacement method. This work has a main objective to present an exact solution for the Moment Distribution Method\nthrough a matrix formulation using only one equation. The initial moments at the ends of the members and the distribution and\ncarry-over factors are calculated from the elementary procedures of structural analysis. Four continuous beams are investigated to\nillustrate the applicability and accuracy of the proposed formulation. The use of a matrix formulation yields excellent results when\ncompared with those in the literature or with a commercial structural program....
To address the rapidly growing demands of traffic congestion, more highway bridges have been constructed, especially curved bridges. With more curved bridges designed and constructed, people have conducted a comprehensive analysis of the structural performance. Due to the nature of the structural complexity of curved bridges, dynamic responses of the curve bridges vary dramatically from the standard linear bridges. Although some work has been conducted to investigate the curved bridge dynamic analysis under seismic inputs, the framework for analyzing the curved bridges’ vulnerability under various angles of inputs is still lacking. In this paper, we conducted a series of curved bridge seismic analyses based on different inputs and conducted a parametric study of the bridge performance using finite element models. We conducted time history analyses by applying seismic inputs to investigate the bridge dynamic responses based on different angle inputs and other different structural parameters. We developed an approach identifying the most vulnerable direction of the seismic inputs and the strongest dynamic responses for curved bridges based on time series analysis. This approach was validated with the dynamic analysis of a simplified bridge model. The method developed in this paper will help improve the curved bridge design code and further provide suggestions about mitigating seismic response for device design....
Molecular dynamics simulations of the phase transformation from bodycentered-\ncubic (bcc) to face-centered-cubic (fcc) structures were performed.\nA Morse-type function was applied, and the parameters were determined so\nthat both fcc and bcc structures were stable for the perfectcrystal model.\nWhen the fcc structure was superior to the bcc structure, the bcc model\ntransformed to fcc. Two mechanisms, based on the Bain and Nishiyama-\nWasserman (NW) relationships, were considered. Then, point or linear lattice\ndefects, i.e. , randomly scattered or regularly aligned vacancies, were introduced.\nConsequently, bcc models tended to transform to an fcc structure,\nwhereas fcc models remained stable. The transformation process was also\ninvestigated in detail. BCC-to-FCC transformation is often considered as a\nhomogeneous process based on changes in the axis lengths, and such a\nprocess was observed for the perfectcrystal model. Conversely, for the defect\nmodels, local heterogeneous deformation patterns, including cylindrical\ndomain and planar interface formation, were observed. These behaviors are\nconsidered to be related to plastic deformation during phase transformation,\nand the validity of the presented model for further investigation was confirmed....
Due to their construction efficiency, prefabricated concrete pavements are becoming a good choice for airport construction or refreshing. However, as a new type of pavement structure, their structural analysis theory and actual structural performance have not been determined. Therefore, a new method based on a neural network is applied to implement a long-term structural assessment, with the input being monitored strain data; it is named the jellyfish search algorithm-optimized BP neural network (JS-BP) model. Considering the structural characteristics, three key parameters are selected as the key parameters to implement the assessment, namely, the bending and tensile modulus, reaction modulus at top of the subgrade, and seam equivalent modulus. To implement the method, the databases are established first with the simulation results from some finite element models of prefabricated concrete pavement. Then, the proposed JS-BP neural network model is trained and checked with the established database. The simulation results verify an excellent accuracy of the proposed method as the difference between the predicted value and the true value is smaller than 1%. Moreover, the aircraft loads show some influence on the prediction results, in which the prediction error is about 5% for most cases, while it is up to 15% for assessing the top surface reaction modulus of the subgrade. Compared with the proposed JS-BP model, the accuracy of the traditional BP model is not so high, as the largest error can be up to 25%. Lastly, the proposed method is verified with some experiments using laboratory models. From the test results it is indicated that the prediction accuracy of the proposed method for the three parameters is still good enough, as the prediction error is within 5%....
Damage pattern recognition research represents one of the most challenging tasks in structural health monitoring (SHM). The vagueness in defining damage and the significant overlap between damage states contribute to the challenges associated with proper damage classification. Uncertainties in the damage features and how they propagate during the damage detection process also contribute to uncertainties in SHM. This paper introduces an integrated method for damage feature extraction and damage recognition. We describe a robust damage detection method that is based on using artificial neural network (ANN) to compute the wavelet energy of acceleration signals acquired from the structure. We suggest using the wavelet energy as a damage feature to classify damage states in structures. A case study is presented that shows the ability of the proposed method to detect and pattern damage using the American Society of Civil Engineers (ASCEs) benchmark structure. It is suggested that an optimal ANN architecture can detect damage occurrence with good accuracy and can provide damage quantification with reasonable accuracy to varying levels of damage....
Green building index is considered as the rating tool for evaluating the siting, design and performance of\r\nbuildings and infrastructures based on worldwide acceptable six main criteria�s It was invented after the Kyoto\r\nprotocol, Japan, on 11th of December 1997 and the adoption in Marrakesh in 2001 by the United Nations and her\r\nsubcommittee. It was developed in the built environment industry by the Government support of each country to\r\ncombat the issue of green house gas emission. Carbon dioxide is acclaimed as one of the main greenhouse gas\r\nemission which is mainly through the activities of human race in the world resulting into global warming hence\r\nthe effort to make the environment lighter enough to inhabit. Construction industry was assessed through studies\r\nto be contributing 5% of the world total carbon dioxide emitted through cement production. It was also claimed\r\nthat a tonne of concrete produces carbon dioxide in the range of 0.05 to 0.13 tonnes. Foam concrete being a new\r\ninnovative green technology material for sustainable building and civil construction needs to fulfill the criteria�s\r\nof this rating tools for it to be considered as sustainable materials. This paper study the assessment of this\r\nlightweight concrete material in view of green building index criteria�s and the result are hereby analyze and\r\nconcluded that foam concrete can be effectively used as sustainable material for building and civil engineering\r\nconstruction....
An overall review of the structural behaviors of ultra-high-performance fiber-reinforced concrete (UHPFRC) elements\nsubjected to various loading conditions needs to be conducted to prevent duplicate research and to promote its practical applications.\nThus, in this study, the behavior of various UHPFRC structures under different loading conditions, such as flexure, shear,\ntorsion, and high-rate loads (impacts and blasts), were synthetically reviewed. In addition, the bond performance between\nUHPFRC and reinforcements, which is fundamental information for the structural performance of reinforced concrete structures,\nwas investigated. The most widely used international recommendations for structural design with UHPFRC throughout the world\n(AFGC-SETRA and JSCE) were specifically introduced in terms of material models and flexural and shear design. Lastly,\nexamples of practical applications of UHPFRC for both architectural and civil structures were examined....
Expansive soils can pose tough issues to civil engineering applications. In a typical year, expansive soils can cause a greater financial loss than earthquakes, floods, hurricanes and tornadoes combined. Various means have been studied to tackle problems associated with expansive soils. The majority of the methods are based on treatment of the soils. While the methods may be effective in some cases, their limitations are also obvious: The treatment normally involves complex processes and may not be eco-friendly in the long run. In many cases, the effectiveness of the treatment is uncertain. A retaining system that maintains a constant lateral pressure is proposed, which consists of three components: the retaining sheet, the slip-force device and the bracing column. The retaining sheet bears the pressure exerted by expansive backfills and is not embedded into the soils. Placed between the retaining sheet and bracing column, the slip-force device permits displacement of the retaining sheet but keeps the force on the sheet and the bracing column constant. The governing equation of the motion of the piston in the slip-force device is derived and a numerical simulation of a practical case is conducted based on the derived governing equation. Numerical results show that as the expansive soil swell, the spring force will increase and the piston will move accordingly. When the pressure of the oil in chamber reaches the open threshold of the unidirectional relief valve, the valve will open and the spring force and the oil pressure in the chamber will keep constant. The results also show that some parameters, such as damping ratio, have very slight influences on the device behavior, say 2 × 10−6 or even 4.8 × 10−9. Theoretical and numerical studies prove the effectiveness of the proposed retaining system....
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