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

Finite element analysis of fire resistant reinforcement on end-plate steel connections

In this paper the effect of fire resistant coatings on the mechanical behaviour of steel joints is studied using the finite element method. The proposed finite element model is an extension of a previous one developed for the study of the same connection in elevated temperatures, without fire reinforcement. In particular, the construction used consists of an end – plate steel connection which is covered with panels of lightweight concrete and gypsum board. The behaviour of those two fire resistant materials has been simulated in elevating mechanical and thermal conditions separately and simultaneously. Through this process it is examined the strength of the materials and of the overall construction. Specifically, the action of fire on the strength of the structure may result in an early collapse. In addition, the behaviour of the structure in the connection area and the opening of the interface is investigated

Rapidly deployable, self forming, wireless networks for maritime interdiction operations

The term "Maritime Interdiction Operations" usually refers to Visit, Board, Search and Seizure (VBSS) operations executed today all over the world. These operations are conducted as a part of the maritime law enforcement policy of each country inside their respective territorial waters or as a part of the homeland security requirements as they are mandated today by the global war against terrorism. Very often lately, they are conducted by allied maritime forces in international waters as well. Although such operations might seem quite simple in execution, the global war against terrorism has dramatically increased their level of complexity. In the past, searching cargo ships for illegal or contraband cargo was not that complicated or that important for national security, but now, searching for non-proliferation, radiological or bio-chemical material, as well as for possible terrorists among the crew members of a ship, is a very complex operation that cannot tolerate mistakes or omissions. This thesis examines the requirements posed by a boarding team, either from the navy or the law enforcement community, on information flow from and to them, in order to enhance their situational awareness and decision making capability during Maritime Interdiction Operations. That information flow is provided by several wireless network technologies, implemented during field trials, as part of the NPS CENETIX (Center for Network Innovation and Experimentation) lab s maritime subset of experimentation. During these field trials, a wireless extension of the internet is deployed to the sea, allowing the boarding team to access information and collaborate with remotely located experts and respective operational commands, the technical aspects, the benefits and shortcomings of the utilized technologies and collaborative tools are screened against the maritime war fighter's operational requirements.http://archive.org/details/rapidlydeployabl109452647Approved for public release; distribution is unlimited

Impact of partially damaged passive protection on the fire response of bolted steel connections using finite element analysis

This article aims to quantify the impact of a potential failure of passive fire protection on the ultimate response of a top and seat steel connection with double web angles. A numerical, finite element analysis scheme is proposed considering the real, semi-rigid behaviour of the connection, using unilateral contact-friction laws between the interfaces of the beam, the column, and the steel angles. The model has been validated by previous experimental research at ambient temperatures. Scenarios of unprotected connections, undamaged and partially damaged fire protections are numerically tested. A change in the failure mode and a reduction of the strength equal to 28% for standard fire and 35% for hydrocarbon fire arise for the model with the damaged protection. In this case, maximum temperatures locally at the beam reach the ones of the unprotected connection (900 °C), which is more than 800 °C higher than the connection with undamaged protection. Significant temperature increases of more than 288 °C and 406 °C for standard and hydrocarbon fires also arise on the top angle, compared to the model with undamaged fire protection

Auxetic metamaterials subjected to dynamic loadings

Materials with negative Poisson?s ratio are called auxetics and they present enhanced properties (e.g. damping, indentation resistance, fracture toughness and impact resistance) under external loadings. The auxetic properties are derived from peculiar-shaped microstructures, such as starshaped frames. In the present investigation, several applications are studied using auxetic microstructures. Finite element models are developed for dynamic analysis. First, an application related to auxetic microstructures, for the core of structural panels, is presented. Next, the use of auxetic materials in armor plates in dynamic bullet penetration problems is considered. Finally, a numerical simulation for wind turbines blades, with aluminum foam, polymeric foam and the proposed auxetic material is carried out. The numerical results demonstrate that the use of auxetic microstructures results in improved dynamic response of the system in comparison to conventional materials

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

Dynamic Morphing of Smart Trusses and Mechanisms Using Fuzzy and Neuro-Fuzzy Techniques

In the present investigation, the principles of dynamic morphing of smart truss structures and mechanisms are discussed. A possible way in order to find the optimal geometry of the structure for the enhancement of structural performance in terms of vibration control is sought. The vibrations of the host dynamic structures are monitored by controllers which are based on the principles of Mamdani-type fuzzy inference and Sugeno-type adaptive neuro-fuzzy inference. More specifically, the objective of the present study is a design, tuning, and an application of robust intelligent control mechanisms by means of the suppression of structural vibrations for several types of excitation forces. The proposed models are discretized by using a finite element method. For the time integration of the equations of motion, the Newmark-β method is used. The calculations and the analysis are conducted within the Matlab environment by using the Adaptive Neuro-Fuzzy Inference System (ANFIS) tool, which is included in the fuzzy toolbox. The controllers are tested with different excitation forces applied on a truss-shaped structure. The control outputs are applied on each time of the simulation in order to achieve the lowest possible deformation and to prevent potential damage or corruption of the structure. The same principles are used for the dynamic morphing of structures and mechanisms. The proposed formulation can be applied, among many others, on smart irrigation systems such as spray booms, on radio-telescope bases, on the spars of smart wings, on aircraft wings etc