Design Proposal for Masonry Infill Walls Subject to Seismic Actions

Several factors influence the behaviour of masonry infilled frames, which have been the subject of previous research with moderate success. The new generation of European design standards imposes the need to prevent the brittle collapse of infills and makes the structural engineer accountable for this requirement, yet it fails to provide sufficient information for masonry infill design. The present study aimed to compare experimental results with the provisions of the standard for the computation of the demand and capacity of infilled frames. Three reinforced concrete buildings with different infill solutions were constructed at a 1:1.5 scale. The infill walls were tested until collapse, or severe damage, using the shake table of the National Laboratory for Civil Engineering, Portugal, and their response was measured using accelerometers attached to the walls. The European normative standard provides results close to the experimental ones as far as demand and capacity are concerned. Based on the experiments, two design proposals for infill walls are presented here, one for the definition of the natural frequency of the infills, and another for a reduction factor to account for the presence of openings in the out-of-plane capacity of infills.

Applications of Cryogenic Electron Microscopy in Biomineralization Research

Biological mineralization is a natural process manifested by living organisms in which inorganic minerals crystallize under the scrupulous control of biomolecules, producing hierarchical organic-inorganic composite structures with physical properties and design that galvanize even the most ardent structural engineer and architect. Understanding the mechanisms that control the formation of biominerals is challenging in the biomimetic engineering of hard tissues. In this regard, the contribution of cryogenic electron microscopy (cryo-EM) has been nothing short of phenomenal. By preserving materials in their native hydrated status and reducing damage caused by ion beam radiation, cryo-EM outperforms conventional transmission electron microscopy in its ability to directly observe the morphologic evolution of mineral precursor phases at different stages of biomineralization with nanoscale spatial resolution and subsecond temporal resolution in 2 or 3 dimensions. In the present review, the development and applications of cryo-EM are discussed to support the use of this powerful technique in dental research. Because of the rapid development of cryogenic sample preparation techniques, direct electron detection, and image-processing algorithms, the last decade has witnessed an exponential increase in the use of cryo-EM in structural biology and materials research. By amalgamating with other analytic techniques, cryo-EM may be used for qualitative and quantitative analyses of the kinetics and thermodynamic mechanisms in which organic macromolecules participate in the transformation of mineral precursors from their original liquid state to amorphous and ultimately crystalline phases. The present review concentrates on the biomineralization of calcium phosphate mineral phases, while that of calcium carbonate, silica, and magnetite is only briefly mentioned. Bioinspired organic matrix–mediated inorganic crystallization strategies are discussed from the perspective of tissue regeneration engineering.

Prefabrication of a Thin Concrete Shell: The Case of St Kevin's Church in Dee Why, Australia

Location of Project: Dee Why, NSW, Australia<br/> Structural Type: Prefabricated thin concrete shell <br/> Project Scale: Length 30 m, width 15.5 m, height 12 m <br/> Owner/Client: Warringah Catholic Parish <br/> Architect: Gibbons & Gibbons Architects <br/> Structural Engineer: Concrete Industries Australia (Monier) Engineers Pty. Ltd.<br/> Construction: Concrete Industries Australia (Monier) Pty. Ltd. <br/> Construction year: 1961<br/>

Aplikasi Jaringan Saraf Tiruan dengan Metode Fungsi Tan-Sigmoid dalam Memprediksi Kinerja Struktur Bangunan Gedung

Gempa bumi merupakan salah satu ancaman terbesar terhadap gedung, sehingga perlu untuk mendesain gedung dengan memperhitungkan pembebanan gempa bumi yang terjadi. Dengan bantuan software finite element dapat diperoleh respons struktur berupa displacement, velocity, dan acceleration yang terjadi akibat gempa bumi. Jaringan Saraf Tiruan (JST) merupakan salah satu metode yang dapat memprediksi kerusakan bangunan dengan memanfaatkan data respons struktur dengan waktu analisis yang relatif lebih singkat dibandingkan menganalisis struktur satu per satu. Penelitian ini bertujuan untuk menganalisis data gempa dengan magnitude intensitas tinggi yang berbeda-beda. Data input dan output diperoleh melalui software Finite Element untuk menghasilkan jumlah data yang diperlukan JST yaitu sebanyak 4489 data. Pada penelitian ini, komposisi yang digunakan untuk training, testing, dan validating adalah 60%, 25%, dan 15% masing – masingnya. Data input yang digunakan yaitu waktu, acceleration arah x dan y, velocity arah x dan y, serta displacement arah x dan y. Sedangkan untuk data target yang digunakan yaitu kinerja struktur yang ditentukan oleh FEMA 356 dan simpangan antar lantai arah x dan y. Hasil pengujian menunjukkan analisis oleh JST yang menggunakan transfer function Tan-Sigmoid menunjukkan nilai R2 sebesar 97,542% dan Mean Square Error (MSE) yang dihasilkan yaitu sebesar 1,2449.E-07. Hal ini menunjukkan analisis JST dengan transfer function Tan-Sigmoid dapat digunakan untuk memprediksi kinerja dari struktur dengan cepat dan akurat. Dengan demikian metode ini diharapkan dapat direkomendasikan untuk Structural Engineer dan perencana gedung dalam mendesain bangunan gedung bertingkat tahan gempa.

Eric Harold Mansfield. 24 May 1923—20 October 2016

Eric Mansfield was a structural engineer who worked at the Royal Aircraft Establishment Farnborough from 1943 to 1983 on a wide range of problems in the field of aircraft structures. His main working tool was the mathematical theory of elasticity, which he deployed with skill, ingenuity, perseverance and imagination to investigate many problems related to the design of aircraft structures during a period of development of higher flight performance and new materials. His studies included aircraft wings and fuselages, particularly in the presence of cut-outs and openings—for which he invented the ‘neutral hole’ concept—and problems involving large-deflection structural behaviour of plates, including thermal effects such as flexural and torsional buckling of fins and wings heated in supersonic flight. He also developed the novel and powerful tension field theory for understanding the post-buckling behaviour of thin webs in shear, and the analogous inextensional bending theory of thin wings. His mathematical models were confirmed by elegant experiments. Mansfield's book The bending and stretching of plates contains clear descriptions of many of his research investigations; it has become a classic text. All of Mansfield's writing is incisive and clear. He was widely regarded as a seminal figure in the field of applied structural mechanics in the second half of the twentieth century.

Design and Analysis of Multistorey (G+14) Residential Building Using Staad.Pro & Autocad

In order to compete in the ever-growing competent market, it is very important for a structural engineer to save time. As a sequel to this an attempt is made to analyze and design a multistoried building by using a software package staad pro. For analyzing a multi storied building one has to consider all the possible loadings and see that the structure is safe against all possible loading conditions. There are several methods for analysis of different frames like kani’s method, cantilever method, portal method, and Matrix method. The present project deals with the design & analysis of a multi storied residential building of G+14 consisting of 2 apartments in each floor. The dead load &live loads are applied and the design for beams, columns, footing is obtained STAAD Pro with its new features surpassed its predecessors and compotators with its data sharing capabilities with other major software like AutoCAD. We conclude that staad pro is a very powerful tool which can save much time and is very accurate in Designs. Thus, it is concluded that staad pro package is suitable for the designof a multistoried building.

Sizing and Topology Optimization of Trusses Using Genetic Algorithm

Genetic algorithms are a robust method for a solution of wide variety optimization problems. It explores a big space of design variables in order to find the best solution. From the point of view of a user, the algorithm requires the encoding of design variables into the form of strings and the procedure of optimization uses them for optimization. Here, for the structural engineer, it is crucial to find the form of objective function including the constraints of the task and also to avoid critical states during the solution of structural responses. This paper presents the use of genetic algorithm for solving truss structures. The use of genetic algorithm approach is shown on three cases of truss structures.