Optimum Design of Outrigger and Belt Truss Systems Using Genetic Algorithm

There are many structural lateral systems used in tall buildings： rigid frames, braced frames, shear walls, tubular structures and core structures. The outrigger and belt truss systems are efficient structures for drift control and base moment reduction in tall buildings where the core alone is not rigid enough to resist lateral loads. Perimeter columns are mobilized for increasing the effective width of the structure, and they developed tension in the windward columns and compression in the leeward columns. Optimum locations for the outriggers have been studied because of the influence on the top displacement and base moment in the core. It was analyzed the optimal position for two to seven outriggers and belt trusses, aiming to achieve minimum bending moment and minimum drift.

Optimization Algorithm for Reduction the Size of Dixon Resultant Matrix:A Case Study on Mechanical Application

In the process of eliminating variables in a symbolic polynomial system,the extraneous factors are referred to the unwanted parameters of resulting polynomial.This paper aims at reducing the number of these factors via optimizing the size of Dixon matrix.An optimal configuration of Dixon matrix would lead to the enhancement of the process of computing the resultant which uses for solving polynomial systems.To do so,an optimization algorithm along with a number of new polynomials is introduced to replace the polynomials and implement a complexity analysis.Moreover,the monomial multipliers are optimally positioned to multiply each of the polynomials.Furthermore,through practical implementation and considering standard and mechanical examples the efficiency of the method is evaluated.

Diagnosis, seismic analysis and reinforcement of an old building in El-Maleh, Algeria

The Northern part of Algeria is considered to be the most active seismogenic area in the Western Mediterranean region. This area has a rich history of seismicity and had experienced many destructive earthquakes such as the Chlef （1954）, El-Asnam （1980）, Beni-Chograne （1994）, AYn-Temouchent （1999） and recently Boumerdes （2003） earthquakes. The earthquake of AYn-Temouchent on December 22, 1999, was of magnitude 5,7, killed at least 28 people and made thousands of families homeless. Consequent damage was seen in all the structures located in a radius of 30 kin. In the city of E1-Maleh, located 12 km northeast of Ain-Temouchent, the ＂The National Bank Branch＂ of E1-Maleh suffered moderate damage, but enough to justify questions about its safety. The project of rehabilitating this building required a broad analysis of its static and dynamic, past and present behaviors. The study reported in this paper was a necessary preliminary step toward the development of an optimal retrofit solution.

Structural Analysis Programme Based on the Equivalent Column＇s Method

The focus of this article is to accomplish a program using MatLab software, which will determine the global behavior of the structure, the stress, stability and frequency of the tall building with ＂n＂ levels. The program starts with the global analyses based on the equivalent column theory. The central core consists of reinforced concrete shear walls of the elevator＇s tubes and of the staircase, design to resist the lateral loads. Applying the equivalent column＇ s theory, the bracing system will be replaced by an equivalent column, considered to be a vertical cantilever fixed at the base and the loads will be applied in the shear center axis. The program using mathematical and physical relations, has as input dates the geometrical and stiffness characteristics of the plan of the building and as output dates the critical load, the fundamental frequency, the maximum stresses and deformations of the structure.

Modelling of the Phenomenon Known as “the Miracle of the Sun” as the Reflection of Light from Ice Crystals Oscillating Synchronously

The work includes a mathematical model of the phenomenon seen by the witnesses on 13th October, 1917 in the Cova da Iria near Fatima, and similar phenomena recorded in recent years throughout the world, known as the “miracle of the Sun”, allowing for qualitative and quantitative analysis of the phenomenon. The work includes a mathematical model of a cloud of the vibrating charged ice crystals. The paper shows the dynamic optical effects associated with the passage of light through such a vibrating medium. It also presents the simplest solution to the model in the form of graphs, which have been compared with the graphs obtained from the analysis of the amateur observations of the phenomenon in question.

Forecasting measured responses of structures using temporal deep learning and dual attention

The objective of this study is to develop a novel and efficient model for forecasting the nonlinear behavior of structures in response to time-varying random excitation.The key idea is to design a deep learning architecture to leverage the relationships,between external excitations and structure's vibration signals,and between historical values and future values,within multiple time-series data.The proposed method consists of two main steps:the first step applies a global attention mechanism to combine multiple-measured time series and time-varying excitation into a weighted time series before feeding it to a temporal architecture;the second step utilizes a self-attention mechanism followed by a fully connected layer to predict multi-step future values.The viability of the proposed method is demonstrated via two case studies involving synthetic data from a three-dimensional(3D)reinforced concrete structure and experimental data from an 18-story steel frame.Furthermore,comparison and robustness studies are carried out,showing that the proposed method outperforms conventional methods and maintains high performance in the presence of noise with an amplitude of less than 10%.

Engineering vibration monitoring by GPS:long duration records

Monitoring the performance of any structure requires real-time measurements of the change of position of critical points. Different techniques can be used for this purpose, each one offering advantages and disadvantages. The technique based on satellite positioning systems （GPS, GLONASS and the future GALILEO） seems to be very promising at least for long period structures. The GPS in particular provides sampling rates that are able to track dynamic displacements with high accuracy. Its service ability is independent of atmospheric conditions, temperature variations and visibility of the monitored object. This paper investigates the reliability and accuracy of the measurements of dual frequency GPS receivers. A linear electromagnetic motor moves an object along a given direction. The changes of position are compared witb their estimates as recorded by a GPS receiver, whose antenna is located on the reference object. The comparison is based on sufficiently long records.

Different Methods on Predicting Deflections on Beams Reinforced with CFRP Bars

The use of fiber reinforced polymer(FRP)bars to substitute the steel bars in internal reinforcement is now an alternative in some structures subjected by corrosion.The strength,stiffness and bond characteristics of FRP bars are tested to understand their flexural behaviour.In this study is investigated the way of failure of beams reinforced internally with carbon FRP(CFRP)bars and their mechanical properties.Two sets of concrete beams reinforced with different diameters of CFRP bars are designed and tested under four-point loading methods.In general,beams reinforced with FRP bars show more deflections and greater values of crack width than beams reinforced with conventional steel,which is due to their low modulus of elasticity and general stiffness.In this paper is presented the calculation and comparison of deflection using different methods,such as ACI 440,CAN/CSA,Eurocode and experimental loading tests.The evaluation is done comparing the results of every method.This study is effective when we use beams with one layer of reinforcement.

Developing a TRL-oriented roadmap for the adoption of biocomposite materials in the construction industry

The construction industry is a major contributor to environmental pollution.The effect of the construction industry on the environment may be mitigated using eco-friendly construction materials,such as biocomposites.Once developed,biocomposites may offer a viable alternative to the current materials in use.However,biocomposites are lagging in terms of adoption and eventual use in the construction industry.This article provides insights into the steps for biocomposites to become a product that is ready to use by the construction industry in a structural role.The development and the adoption of such a material is tackled with the use of two concepts,i.e.,technology readiness level and roadmapping,and explored in a case study on the“liquid wood”.Furthermore,interviews in the construction industry are carried out to identify the industry’s take on biocomposites.A customized roadmap,which underlines a mostly nontechnical perspective concerning this material,has emerged.Additionally,the adoption and diffusion issues that the“liquid wood”may encounter are outlined and complemented with further recommendations.