Lecture

Beams under nonuniform bending: Shear stresses and shear flow

Graph Chat

Chat with Graph Search

Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.

DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.

In course

CIVIL-238: Structural mechanics (for GC)

The course discusses the basic principles of structural mechanics, analyzing the performance of materials and structures against loading and focuses on the stress strain relationships and the effect of axial, bending, shear and torsional loadings on engin ...

Description

This lecture covers the analysis of beams under nonuniform bending, focusing on shear stresses and shear flow. The instructor discusses the distribution of shear stresses in rectangular and circular cross-section beams, as well as in built-up beams. Derivations of shear formulas for rectangular beams are presented, along with examples to visualize shear stresses. The lecture also addresses the design of beams for stresses due to flexure, emphasizing the relative efficiency of various beam shapes. Furthermore, the distribution of shear stresses in beams with flanges is explored, highlighting the complexity of shear stress distribution in I-shaped beams. Various examples and calculations are provided to illustrate the concepts discussed.

Instructors (2)

Anastasios Vassilopoulos

PERSONAL INFORMATION Name : Anastasios P. Vassilopoulos email : anastasios.vassilopoulos@epfl.ch Tel: 41 21 6936393 Fax: 41 21 6936240 SUMMARY OF QUALIFICATIONS 1995: Dipl. Mechanical Engineer, University of Patras, Greece 2001: Dr Mechanical Engineer, Doctoral thesis in fatigue of composite materials from the Dept. Mechanical Engineering and Aeronautics, University of Patras, Greece CURRENT POSITION Senior Scientist (MER), Composite Construction Laboaratory (CCLab), EPFL PREVIOUS POSITIONS 2006-2012 Research and Teaching Associate, Composite Construction Laboaratory (CCLab), EPFL 2002-2006 Assisstant Professor, Technological Educational Institute (TEI) of Patras, Greece 2001-2003 Post-doctoral Research associate, (Part-time) Dept. Mechanical Engineering and Aeronautics of the University of Patras, Greece. EDUCATION 1990 - 1995 Graduate student, Dept. Mechanical Engineering and Aeronautics, University of Patras, Greece October 1994-January 1995 Dept. Mechanical Engineering, University of Bristol, U.K. (In the frame of Erasmus project for the final year thesis, under the supervision of Prof. R. D. Adams) 1995 - 2000 Research assistant, Dept. Mechanical Engineering and Aeronautics, University of Patras. LANGUAGES English, Greek, French COMMUNITY ACTIVITIES (Member of) Council of the European Society of Composite Materials (ESCM) Council of the European Society of Experimental Mechanics (EuraSEM) The European Structural Integrity Society (ESIS) The European Energy Research Alliance (EERA, JP WIND) The Technical Chamber of Greece (TCG) The Hellenic Association of Mechanical & Electrical Engineers SCIENTIFIC-RESEARCH INTERESTS Experimental methods for the study of the behavior of composite materials under static and fatigue loading Development of analytical methods for the study of the behavior of FRP composite materials under variable amplitude complex stress states Development of fatigue life prediction methodologies for composite materials and structures Design of constructions with composite materials

Dimitrios Lignos

Prof. Lignos joined the École Polytechnique Féderale de Lausanne (EPFL) in 2016 from McGill University in Canada where he was a tenured Associate Professor and a William Dawson Scholar for Infrastructure Resilience. He holds a diploma (National Technical University of Athens, NTUA, 2003), M.S. (Stanford University, 2004) and Ph.D. (Stanford University, 2008). In addition, he was a post-doctoral scientist at Stanford University (2009) and in Kyoto University (2010). Prof. Lignos teaches graduate and undergraduate courses in seismic design, nonlinear behaviour of steel and composite structures as well as supplemental damping systems, Structural Stability, Nonlinear Analysis and Performance-based Earthquake Engineering. His awards for teaching, research and service in Civil Engineering include the 2011 Outstanding Teaching Award (Faculty of Engineering, McGill University), as well as the Outstanding reviewer (2012, 2013) award from ASCE, the 2013 State-of-the-Art in Civil Engineering Award by ASCE and the 2014 Christophe Pierre Award for Research Excellence - Early Career. Just recently, he received the 2019 Walter L. Huber Civil Engineering Research Prize from ASCE for significant contributions in developing state of the art methods to simulate extreme limit states in steel structures.Prof. Lignos is a member of ASCE and the Earthquake Engineering Research Institute. He acts as an Associate Editor for Metal Structures and Seismic Effects of the ASCE Journal of Structural Engineering. He joined the Editorial Board of Earthquake Spectra and Earthquake Engineering and Structural Dynamics International journals. He serves as an acting member of the CEN/TC 250/SC 8/WG 2 and has been selected as a member of the Project Team (PT2) for the Eurocode 8-Part 1 Current Revisions for Steel and Composite Structures. He is also a member of the Canadian Standards Association (CSA) S16 technical committee for Steel Structures. Prof. Lignos is involved as a NEHRP consultant in numerous research-to-practice projects related to the behaviour and nonlinear modelling and analysis of structures applicable to the engineering practice through the Applied Technology Council (ATC). Detailed Curriculum Vitae (last update September 2018)

Official source

Related concepts (32)

Beam (structure)

A beam is a structural element that primarily resists loads applied laterally to the beam's axis (an element designed to carry primarily axial load would be a strut or column). Its mode of deflection is primarily by bending. The loads applied to the beam result in reaction forces at the beam's support points. The total effect of all the forces acting on the beam is to produce shear forces and bending moments within the beams, that in turn induce internal stresses, strains and deflections of the beam.

Shear stress

Shear stress (often denoted by τ (Greek: tau)) is the component of stress coplanar with a material cross section. It arises from the shear force, the component of force vector parallel to the material cross section. Normal stress, on the other hand, arises from the force vector component perpendicular to the material cross section on which it acts. The formula to calculate average shear stress is force per unit area.: where: τ = the shear stress; F = the force applied; A = the cross-sectional area of material with area parallel to the applied force vector.

I-beam

I-beam is a generic lay term for a variety of structural members with an or -shaped cross-section. Technical terms for similar items include H-beam (for universal column, UC), w-beam (for "wide flange"), universal beam (UB), rolled steel joist (RSJ), or double-T (especially in Polish, Bulgarian, Spanish, Italian and German). I-beams are typically made of structural steel and serve a wide variety of construction uses. The horizontal elements of the are called flanges, and the vertical element is known as the "web".

T-beam

A T-beam (or tee beam), used in construction, is a load-bearing structure of reinforced concrete, wood or metal, with a -shaped cross section. The top of the -shaped cross section serves as a flange or compression member in resisting compressive stresses. The web (vertical section) of the beam below the compression flange serves to resist shear stress. When used for highway bridges the beam incorporates reinforcing bars in the bottom of the beam to resist the tensile stresses which occur during bending.

Non-Newtonian fluid

A non-Newtonian fluid is a fluid that does not follow Newton's law of viscosity, that is, it has variable viscosity dependent on stress. In non-Newtonian fluids, viscosity can change when under force to either more liquid or more solid. Ketchup, for example, becomes runnier when shaken and is thus a non-Newtonian fluid. Many salt solutions and molten polymers are , as are many commonly found substances such as custard, toothpaste, starch suspensions, corn starch, paint, blood, melted butter, and shampoo.

Related lectures (64)

Beams under nonuniform bending: Shear stresses and built-up beams

Covers shear stresses in beams and built-up beams, including shear flow calculations and stress superimposition.

Understanding Viscosity: Newtonian Fluids

Explores viscosity in Newtonian fluids, discussing shear stress, shear strain rate, and compressibility, with examples of shear thickening and shear thinning behaviors.

Shear Stresses in Beams

Explores shear stresses in beams, including their distribution and calculation of shear and moment diagrams.

Mechanics of Composite Beams

Explores stresses in composite beams, including normal stresses, longitudinal strains, and moment-curvature relationship.