Life cycle analysis of a steel building

The present study tries to couple structural optimization problems for building frames, with that of energy efficiency optimization. The objective function of the problem takes into account the following parameters: heat capacity, wall and window insulation pro-file, window sizes, losses due to ventilation, boiler and air conditioning system sizing, sizing of steel cross-sections as well as parameters related to the life cycle of the building. Modeling is based on acceptable from national and European regulations procedures. Optimization is solved us-ing evolutionary algorithms. The optimization problem is implemented on a steel building (10x15 m), in Chania, Greece. This is a first attempt to combine Life Cycle Cost and Optimization with classical Structural Optimization for steel structures. Depending on the requirements from the users of the building further evaluation using building energy management system (BEMS) for the intelligent op-eration and management of heating, ventilation and air-conditioning (HVAC) may be performed

Life Cycle Assessment of a Steel-Framed Residential Building

One of the most widely acknowledged policies, which is also strongly promoted by legislation and government officials globally, is sustainable development. Since the introduction of the term and the development of its content, the movement for sustainable development has been accepted by all business sectors as a set of principles that have to be incorporated into standard practice. Particularly in the case of business sectors such as construction that have been identified as the largest consumers of raw materials and energy there has been considerable pressure to optimize processes in terms of sustainability, with particular emphasis on the environmental impact caused. Steel structures constitute a construction technology which holds significant potential in terms of sustainability. The purpose of the current research is to quantify this potential by calculating the environmental impact caused throughout the life cycle of a steel-framed residential building. A life cycle assessment is conducted, taking into account issues such as raw material acquisition, construction and waste management. The results obtained are used to draw conclusions regarding the application of the life cycle assessment methodology to steel buildings and the environmental data required. Furthermore, observations regarding the quantification of the environmental impact caused by the steel-framed residential building and the identification of the most environmentally damaging processes in regard to the life cycle of the building are also made

Innovative and sustainable use of stream water to suppress fires in protected areas: overview of the streams-2-suppress-fires project

Establishing protected areas to maintain biodiversity is a priority worldwide. Protected areas can have minimal management practices that can lead to the intensive accumulation of fire fuel. Fires are major threats for all protected areas that cause irreversible damages to them or impacts that last for decades or even centuries. The impending climate change impacts will increase the potential of large fires even in regions with minimal fires in the past. The emphasis of this project is in the Black Sea region with six pilot areas in six different countries. The first action involves the establishment of a Neighborhood Network regarding fire suppression around the region. The network includes institutions that are responsible for mitigating forest fires and managing protected areas from the Black Sea region. Another important action taken is to understand the fire behavior and locating the areas with the greatest fire risk. When considering fire suppression it is essential to know the available water resources (stream water). Since fires occur during the summer, the runoff and stream flow during this period needs to be accurately predicted. Based on the fire behavior and water resources data, the number, dimensions of the reservoirs required to suppress forest fires will be estimated for the pilot areas. Finally, specialized software will provide the optimal locations of the reservoirs and the best routes for the fire vehicles to reach the reservoirs. Overall the use of innovative mechanisms will lead to the more cost-effective management that will allow the sustainable development and protection of natural protected areas

Numerical and experimental investigation of the behavior of extended end-plate connections in steel structures

It is well known that one of the most popular methods of connecting members in structural steel work is the bolted end-plate connection. Bolted end-plates are simple in their use and construction. But they are extremely complex in term of analysis and behavior since the connection behavior significantly affects the structural frame response and therefore it has to be included to the global analysis and the design of frame. The present paper deals with the structural behavior of full-scale stiffened and un-stiffened cantilever connections of typical I sections. The connection between the extended end-plate to the column flange is achieved by means of high strength bolts in each case. In order to obtain experimentally the actual tension force induced within each bolt, strain gauges were installed inside each one of the top bolts. Thus, the connection behavior is characterized by the tension force in the bolt, the extended end-plate behavior, the moment-rotation relation and the beam and column strains. Thereby, it is important to predict the global behavior of column-beam connections by means of their geometrical and mechanical properties. The experimental test results are compared to those obtained by means of a numerical approach based on the finite element method and is coupled to the theory of non-smooth mechanics. All the arising non-linearities in the connection are described through a non-monotone multi-valued reaction-displacement law. Thus, the problem is formulated as a hemivariational inequality leading to a sub-stationarity problem of the potential or the complementary energy of the connection. This simulation problem is solved by applying a non-convex non-smooth optimization algorithm. The comparison of the results of the experimental testing program with the numerical simulation proves the effectiveness of the proposed numerical method

Tightening and loosening torque of M253M bolts: Experimental and analytical investigation

The present paper deals with the study of the installation behavior of high-strength bolts under friction. For this purpose an experimental program was conducted to evaluate the energy of these bolts that is dissipated due to tightening and loosening. The total number of tested specimens was 100 bolts furnished to the requirements of AASHTO specification M253M. The turn-of-nut tightening method is applied experimentally to evaluate the pretension and the torque for tightening and loosening of bolts. It is mentioned that a number of 56 bolts has 76 mm length while the rest is of 152 mm. The experimental preloading and the lost torque that overcomes friction are compared with the respective analytical values. It is confirmed that the K-nut factor is affected by the type of lubricant and the length of the bolt. Additionally, most of torque is going to overcome friction. The percentage of tightening and loosening torque for both the analytical and the experimental cases is very close

Unilateral contact effects in the structural response of beam-to-column connections

One of the most usual choices for the connection between the different structural members in steel structures is the bolted connection. The later provide a high level of deformation capacity for the whole structure and a level of stiffness comparable to that of fully welded connections. Top and seated angle with double web angle bolted connections are primarily used for beam-to-column joints. The most important factor for the structural response of beam-tocolumn connections is the rotational stiffness because it affects the behavior of the overall structural steel frame. For this purpose, many experimental tests have been recently conducted to obtain moment-rotation curves. Considering the moment-rotation curves obtained from experimental tests, a simplified analytical model has been suggested to predict the behavior of the connection by fitting techniques. The aim of the present paper is, from one side, the development of a moment-rotation curve for bolted top and seat angle connection with double web angle by means of a proposed theoretical model whose validity checked by comparison with experimental data, and from the other side, the determination of the appearing prying forces in the bolts by means of a simplified and reliable model

Experimental and numerical investigation of the structural response of top and seated angle with double web angle bolted connections

The aim of the present paper is the experimental and numerical investigation of the unilateral contact effect to the structural response of top and seated angle with double web angle bolted connections. The experimental study is focused on the study of ductility, deformability, moment capacity, bolts prying force and contact zone of these connections. Six full-scale top and seat angles with double web angle bolted connections were tested. Static vertical load was applied until the specimens to reach a condition that cannot resist any additional load after that. In parallel, a finite element analysis was developed to simulate the aforementioned test and in particular, to determine the contact area between the top angles with the column flange, given rise to additional forces, the so-called prying forces. The finite element results were compared to the experimental ones and to those derived theoretically from the application of a model that recently has been proposed in the literature

Crisp and fuzzy advanced hierarchhy process for the design of an industrial building based timber and steel elements

Summarization: Sustainable Development (SD) emerged in the late 90’s, as a response to severe environmental prob- lems worldwide and the public pressure they created. SD introduced the notion of environmental and social con- sequences of anthropogenic activity, affecting the paradigm of ’business as usual’ and increasing the complexity of design and implementation of new, environmentally and socially responsible, strategies. Decision making under these new coordinates has to tackle with both quantitative and qualitative information, as well as the relationship between the two. A combination of different knowledge domains, and the different methodological options they introduce, is necessary for tackling complex problems. This research focuses on this (new) challenge, specifically for the construction sector. Two methods, crisp and fuzzy Analytical Hierarchical Process (AHP), are used for the evaluation of the design of a (generic) industrial building. A decision making process is developed, where a prob- lem hierarchy is created, expert knowledge is gathered and evaluated and final priorities of alternative solutions are produced, through a crisp and a fuzzy handling of data. The case study offers a first exploration, indicating the applicability and easy of use of the methods, presenting preliminary results and proposing further research trajectories.Presented on