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Lecture

Definition of Lattices

In course

CIVIL-124: Statics (for GC)

Ce cours a pour but de développer une compréhension des modèles statiques de structures. Il présente l'étude du jeu des forces dans les constructions isostatiques formées de barres, poutres et câbles. ...

Description

This lecture covers the equilibrium of lattice fragments, trellis isostaticity, analysis methods, knot balance, and the definition of trellises. It explains how to determine if a lattice is isostatic, identify bars efficiently, and calculate forces using different methods.

Instructors (2)

Emmanuel Denarié

Emmanuel Denarié is a civil engineer, with a PhD in Materials Science. He worked for 3 years in a civil engineering company where he was in charge of the design of structures and the maintenance of bridges. He has 30 years’ experience on research and applications in the field of building materials, advanced concretes, and rehabilitation of reinforced concrete structures. He is since 2000 senior scientist and lecturer in the Laboratory for Maintenance and Safety of structures, at Ecole Polytechnique Fédérale de Lausanne (EPFL), in charge of research and development activities on the application of concretes and advanced cementitious materials to the improvement of existing and new structures. In 2013, under the lead of Emmanuel Denarié, in cooperation with CEREMA, Subdivision des Phares et Balises from Lorient, and Lafarge, a turret at sea (Le Cabon, Brittany, France) was reinforced by a cast on site 60 mm thick UHPFRC shell. The strain hardening mix was developed jointly with Lafarge. This successful application in extreme conditions of access and restraint of the substrate (thin ring geometry) opened the way to large-scale industrial applications of UHPFRC for the reinforcement of existing structures.

Katrin Beyer

Since 2017 Associate Professor, School of Architecture, Civil and Environmental Engineering (ENAC), EPFL. Head of the Earthquake Engineering and Structural Dynamics (EESD) Laboratory 2010-2017 Assistant Professor, EPFL. 2008-2010 Post-doctoral researcher, ETH Zürich. 2003-2007 Ph.D., Roseschool / Università di Pavia, Italy. 2001-2003 Ove Arup & Partners, Advanced Technology and Research Group, London. 2001 Diploma, Civil engineering, ETH Zürich.

Official source

Related concepts (8)

Economic equilibrium

In economics, economic equilibrium is a situation in which economic forces such as supply and demand are balanced and in the absence of external influences the (equilibrium) values of economic variables will not change. For example, in the standard text perfect competition, equilibrium occurs at the point at which quantity demanded and quantity supplied are equal. Market equilibrium in this case is a condition where a market price is established through competition such that the amount of goods or services sought by buyers is equal to the amount of goods or services produced by sellers.

General equilibrium theory

In economics, general equilibrium theory attempts to explain the behavior of supply, demand, and prices in a whole economy with several or many interacting markets, by seeking to prove that the interaction of demand and supply will result in an overall general equilibrium. General equilibrium theory contrasts with the theory of partial equilibrium, which analyzes a specific part of an economy while its other factors are held constant.

Force

In physics, a force is an influence that can cause an object to change its velocity, i.e., to accelerate, unless counterbalanced by other forces. The concept of force makes the everyday notion of pushing or pulling mathematically precise. Because the magnitude and direction of a force are both important, force is a vector quantity. It is measured in the SI unit of newton (N) and often represented by the symbol F.

Competitive equilibrium

Competitive equilibrium (also called: Walrasian equilibrium) is a concept of economic equilibrium, introduced by Kenneth Arrow and Gérard Debreu in 1951, appropriate for the analysis of commodity markets with flexible prices and many traders, and serving as the benchmark of efficiency in economic analysis. It relies crucially on the assumption of a competitive environment where each trader decides upon a quantity that is so small compared to the total quantity traded in the market that their individual transactions have no influence on the prices.

Mechanical equilibrium

In classical mechanics, a particle is in mechanical equilibrium if the net force on that particle is zero. By extension, a physical system made up of many parts is in mechanical equilibrium if the net force on each of its individual parts is zero. In addition to defining mechanical equilibrium in terms of force, there are many alternative definitions for mechanical equilibrium which are all mathematically equivalent. In terms of momentum, a system is in equilibrium if the momentum of its parts is all constant.

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