Mechanic of Materials and Construction

A hydrodynamic voltammetrric method was developed to determine the concentration of atmospheric nitrogen dioxide. Air samples were collected in 0.1M NaOH scrubbing solution which converts NO 2 to NO 2 and NO 3 in a fixed stoichiometric ratio. The produced NO 2 ion was analyzed by hydrodynamic voltammetry at a rotating disk gold electrode. A calibration curve was established by plotting the anodic steady state current (i s ) versus NO 2 concentration. The calibration curve showed a remarkable linearity between the steady state current for NO 2 oxidation and NO 2 ion concentration (correlation coefficient = 0.9975). The Validity of the method was checked against spectrophotometric determination of NO 2 -. The agreement between the two methods was confirmed (R 2 = 0.9965). The applicability of the method to real-life analysis was established by estimation of NO 2 concentration in ambient air of three districts in Amman. The results indicated that the atmospheric concentration of NO 2 in the three districts conforms to the international and national atmospheric clean air standards.

The paper presents a formulation in the frequency domain for the viscoelastic material behaviour of structural elements. This approach is equally valid for deterministic forces, but also in the case of probabilistic descriptions of those forces. The method takes advantage of readily available experimental data and shows how to introduce them in e.g. finite element formulations.

The cyclic behaviour of a double-edge notched specimen loaded in tension is studied. Cracks in the material are modelled by displacement discontinuities that can propagate during computation. Within these discontinuities, a cohesive zone model is used. The model assumes an additive split of the inelastic jump into a recoverable and an unrecoverable part. The in uence of model parameters and discretisation is studied and the results have been compared with experimental data.

The cyclic behaviour of a double-edge notched specimen loaded in tension is studied. Cracks in the material are modelled by displacement discontinuities that can propagate during computation. Within these discontinuities, a cohesive zone model is used. The model assumes an additive split of the inelastic jump into a recoverable and an unrecoverable part. The influence of model parameters and discretisation is studied and the results have been compared with experimental data.

In this paper, a combined experimental-computational study of double-edge notched stone specimen subject to cyclic tensile loading is presented. In the experimental part, the load-deformation response and the local displacement field are recorded. Both experimental results are used to validate a numerical model for the description of fracture within finite elements. The model uses displacement discontinuities to model cracks. These discontinuities are implemented using the partition of unity property of finite element shape functions. In the discontinuity, a combined damage-plasticity cohesive law is used. Numerical simulations are compared with experimental observations.

Two departments of Vrije Universiteit Brussels (VUB), being the Department of Architectural Engineering (ARCH) and the Department of Mechanics of Materials and Constructions (MeMC), both in the Faculty of Engineering, are both scientifically active in various aspects of structural and architectural engineering. What, at first sight, could be seen as reciprocal attempts to cover each other’s fields of research activities is far from the truth. On the contrary, their continuous collaboration, which originated years ago, showed an intense synergy, not only in the field of scientific research, but also in teaching and external activities. The present paper illustrates that statement with case studies, taken in the three activity components, from the point of view of the structural engineer and shows that \“one and one can be (significantly) more than two”. A parallel paper will report on the point of view of the architectural engineer at VUB. Keywords: civil and structural engineering, ...

Abstract. A mixed numerical experimental approach is the basis of a new method for the identifi-cation of the material damping properties of fibre reinforced polymers, which provides an answer to many problems encountered in experimental damping characterization. ...

Measurement of the material properties of a circular plate with cylindrical orthotropy is dicult. This paper presents a method for the identi®cation of plate rigidities of a circular plate with cylindrical orthotropy using vibration data. The method is based on the so-called mixed numerical/experimental method and relies basically on three items: (1) an accurate numerical model of the circular disk; (2) a set of reliable experimental modal model data; (3) a fast and robust parameter estimation method.

Within the framework of sustainable development we strive for constructions with a minimum volume of material. When we only consider criteria on resistance and buckling, at the stage of conceptual design a clear hierarchy among the different structural topologies can be established with Morphological Indicators (MI). MI are dimensionless numbers that represent a property of a structure (e.g. volume) and depend only on a small number of dimensionless variables (in its most simple appearance only the slenderness of the structure). We define the slenderness as L/H, L being the horizontal and H the vertical dimension of the rectangle that inscribes the structure. This allows one to compare the efficiency of structures objectively, with only a reduced number of variables to consider. Hence MI allow a very quick shape and topology optimisation at the conceptual design stage if only element strength (resistance) and buckling are to be considered. Though a lot of design problems, especially for lightweight structures, are characterized by stiffness constraints: global instability, upper limit on static displacements, acceptable vibrations… In such cases one of the main assumptions of the theory of MI is not valid, since fully stressed design does no longer guarantee the optimal section distribution. Therefore, problems subjected to stiffness related constraints have to be analyzed by different methods allowing the optimisation of the sizing of the different elements. Recent research enables determination of whether one has to deal with a design for strength or a design for stiffness problems. This paper presents schematically the theory of MI and the method to distinguish a strength characterized problem from a stiffness characterized one at the conceptual design stage. An example illustrates the design process. The principal aim is not to criticize the efficiency of the theory of MI but to point out when the theory can be applied and when not.

Catastrophes like wars and natural disasters have occurred over the ages. However, in the last decade the number of emergency situations has increased in a frightening way. Unsustainable human behaviour causing environmental changes and social conflicts undoubtedly contributes to this increase. A global approach for shelter intervention may contribute to efficient relief while supporting a transition from aid to development and helping to prevent future catastrophes. In this paper one investigates how the "4-dimensional design strategy" developed at the Vrije Universiteit Brussel (department of Arch & MeMC) can be implemented to reach this goal.

Національний технічний університет України «Київський політехнічний інститут імені Ігоря Сікорського» ЛІНГВОКУЛЬТУРНІ ОСОБЛИВОСТІ ПЕРЕКЛАДУ СУЧАСНИХ АНГЛОМОВНИХ ДОКУМЕНТАЛЬНИХ ФІЛЬМІВ Анотація. В даній статті розглядаються проблеми, які виникають в процесі перекладу сучасних англомовних документальних фільмів. Вивчено поняття «кінотекст», визначено, що переклад кіносценаріїв відноситься до художнього перекладу та в той же час має свої унікальні особливості. Досліджено англомовний документальний кінотекст як об'єкт лінгвістичного дослідження та розглянули методи трансляції подій в англомовному документальному кінотексті. Також, проаналізовано лінгвокультурні особливості перекладу сучасних англомовних документальних фільмів. Ми дослідили лінгвокультурний потенціал сучасних англомовних документальних фільмів, їх значення, особливості, жанрово-стилістичну специфіку та розгляд науковцями в парадигмі мультимодальності. З'ясовано лінгвокультурну специфіку перекладу мови англомовних документальних кінотекстів. Виявили лінгвокультурний аспект перекладу англомовних документальних кіно текстів та специфіку перекладу документальних фільмів, зокрема, із субтитрами. Було проаналізовано два документальні фільми: «Земляни» та «Пластиковий океан», охарактеризовано переклад, підкреслення складнощів під час перекладу фільмів такого типу в зв'язку з залежністю від часового проміжку, який віддається на оригінальний текст. Найважливішим є обрати такі перекладацькі трансформації, за допомогою яких переклад не буде ані сильно поспішати, ані відставати. У обох фільмах цей баланс було дуже добре продемонстровано. Ключові слова: кінотекст, документальний кінотекст, аспекти перекладу, лінгвокультурний аспект, трансляція подій.

Morphological indicators are a powerful tool to optimize structures at an early stage of the design process, because of their dependence on few variables which are usually known early in the design process. Furthermore they allow us to compare structural performance on an objective base. Yet for complex cases it is difficult to find optima with indirect methods. One has to resort to other optimization techniques. Genetic algorithms are promising at searching in large and complex search spaces. A genetic algorithm is proposed with a morphological indicator as an objective function. This study is limited to the optimization of statically determinate planar trusses with simple load-cases.

This work deals to the determination of the expansion ratio () and compression index () of soil samples taken at several points around the Wouri coast river of Cameroon. These parameters are the most important soil parameters, necessary to be known before each building project. The undisturbed soils samples are taken at nine different points labeled as P1, P2... P9 at the depths varying from 5m to 9.5 m and distanced around 10 to 15 meters. These studies are motivated by the fact that in this region, mechanical properties of soil have huge effects on buildings. By plotting the void ratio as a function of the logarithm of the pressure, these mechanical parameters are found and compared to that obtained from the inner land of Cameroon, Yaoundé town chosen as an example. As a result, this comparison has allowed us to classify the soil and give some practical advantages when carrying out civil engineering works such as buildings, bridges in coastal area.