Finite Element Method for Evaluating Rising and Slip of Column–Base Plate for Usual Connections

Предложена конечноэлементная методика расчета деформирования и относительного проскальзывания креплений стальной колонны кжелезобетонному основанию. Рассмотрены два случая крепления: пластина приваривается к торцу колонны и крепится двумя или четырьмя анкерными болтами к железобетонному основанию. В конечноэлементной модели с использованием модифицированного метода Лагранжа учитывается растрескивание бетонного основания и эффекты трения. Деформирование бетонного основания описывается с помощью упругопластической модели сжатия материала. По результатам расчетов построены диаграммы перемещений элементов крепления.Запропоновано скінченноелементну методику розрахунку деформування і відносного проковзування кріплень стальної колони до залізобетонної основи. Розглянуто два випадки кріплення: пластина приварюється до торця колони і кріпиться двома або чотирма анкерними болтами до залізобетонної основи. У скінченноелементній моделі з використанням модифікованого методу Лагранжа враховується розтріскування бетонної основи й ефекти тертя. Деформування бетонної основи описується за допомогоюпружно-пластичної моделі стиску матеріалу. За результатами розрахунків побудовано діаграми переміщень елементів кріплення

Fatigue limit of recycled aggregate concrete

This paper presents the main results of the research carried out to obtain the fatigue limit of concrete incorporating recycled aggregate from concrete. In this research, recycled aggregate concretes with partial and total coarse aggregate replacement and control concretes with different increasing water/cement ratios have been cast to study the material’s behavior in response to repeated compressive loads. The results show that, for the same water/cement ratio, the recycled aggregate concretes present a loss of stiffness higher than the control concrete. Furthermore, the use of recycled aggregate in concrete implies a reduction of the fatigue life. These differences are increased for low water/cement ratios, as in this case the main factor is the lower strength capacity of the aggregate. From the results obtained, recommendable mixtures for recycled aggregates exposed to fatigue loads are proposed

Finite element method for the rising and the slip of column-plate base for usual connections

In the present paper, a finite element approach calculating the rising and the relative slip of steel base plate connections is proposed. Two types of connections are studied, the first consists on a base plate welded to the column end and attached to the reinforced concrete foundation by two anchor bolts. These bolts are placed on the major axis of the I shaped section used as column, one anchor bolt on each side of the web. In the second configuration, the connection includes a plate base and four anchor bolts placed out side the flanges of the I shaped section or hallow form. To take in account the real behaviour of this connection, a model by finite elements which considers count geometrical and material no linearties of the contact and cracking in the concrete foundation. To study the rising of the base plate, an approach treating problems of contact-friction between the base plate and the foundation is developed. This approach is based on a unilateral contact law in which a Coulomb friction is added. The numerical resolution is ensured by the increased Lagrangien method. For the behaviour of the concrete foundation, the developed model is based of a compressive elastoplastic model. The heights rising-rotations and the heights rising- slip displacements curves are plotted

Packet Routing Simulator for Multi-Agent Reinforcement Learning (PRISMA) (Version v0.1)

PRISMA (Packet Routing Simulator for Multi-Agent Reinforcement Learning) is a network simulation playground for developing and testing Multi-Agent Reinforcement Learning (MARL) solutions for dynamic packet routing (DPR). This framework is based on the OpenAI Gym toolkit and the ns-3 simulator.The OpenAI Gym is a toolkit for RL widely used in research. The network simulator ns–3 is a standard library, which may provide useful simulation tools. It generates discrete events and provides several protocol implementations.Moreover, the NetSim implementation is based on ns3-gym, which integrates OpenAI Gym and ns-3.The main contributions of this framework: 1) A RL framework designed for specifically the DPR problem, serving as a playground where the community can easily validate their own RL approaches and compare them. 2) A more realistic modelling based on: (i) the well-known ns-3 network simulator, and (ii) a multi-threaded implementation for each agent. 3) A modular code design, which allows a researcher to test their own RL algorithm for the DPR problem, without needing to work on the implementation of the environment

Estimation of the Wind Energy Potential in Various North Algerian Regions

This investigation aims to model and assess the wind potential available in seven specific regions of North Algeria. These regions, i.e., Batna, Guelma, Medea, Meliana, Chlef, Tiaret, and Tlemcen, are known for their traditional agriculture. The wind data are obtained from the National Agency of Meteorology (NAM), and a Weibull distribution is applied. In the first part of this study, the wind potential available in these sites is assessed. Then, different models are used to estimate the wind system’s annual recoverable energy for these regions. We are interested in wind pumping for possible use to meet the needs of irrigation water in rural areas. Four kinds of wind turbines are explored to determine the possibility of wind energy conversion. In addition, the effects of the heights of the pylon holding the turbines are inspected by considering four cases (10, 20, 40, and 60 m). This estimation showed that the annual mean wind velocity varies from 2.48 to 5.60 m/s at a level of 10 m. The yearly values of Weibull parameters (k and c) at the studied sites varied within 1.61–2.43 and 3.32–6.20 m/s, respectively. The average wind power density ranged from 11.48 (at Chlef) to 238.43 W/m2 (at Tiaret), and the monthly wind recoverable potential varied from 16.64 to 138 W/m2

Etude du comportement a la rupture d'une structure endommagee par sollicitation dynamique: endommagement du beton en fatigue

CNRS AR 12529 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueSIGLEFRFranc