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Introduction to TOS-I

Learn about the history of structural engineering, different forms of structures, materials, and loads in this comprehensive lecture series.

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Introduction to TOS-I

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  1. Introduction to TOS-I Theory of Structure - I

  2. Lecture Outlines • Introduction • History of Structural Engineering • Forms of Structures • Materials • Loads

  3. Introduction STRUCTURAL ENGINEERING 1ST YEAR 2ND YEAR 3RD YEAR 4TH YEAR ENGG. MECHANICS THEORY OF STRUCTURES I THEORY OF STRUCTURES II STRUC. ENGG.

  4. History of Structural Engineering • Why history is important? • One reason why history is important it that the past has value to our society. • History is the narrative of mankind. • History when presented properly lends itself to critical analysis.

  5. History of Structural Engineering • Greek and Egyptian Temples • Made of stone • Employed beams and columns • Many columns having little useful space between them

  6. Greek temple built 2500 years ago

  7. Greek temples of Poseidonia (now called Paestum) dating from the sixth century BC.

  8. The Temple of Debod built in early 2nd century BC

  9. Egypt: Temples of Karnak built 2000 years ago

  10. History of Structural Engineering • Arch structures were discovered prior to Roman era. • Roman Empire used arches extensively in construction. • Stone arches had span of 100 ft and more

  11. The Colosseum is one of Rome's most distinctive landmarks.  Construction of this famous amphitheatre began in 72 AD.

  12. Arches Aqueducts Aqueduct at Segovia in eastern Spain

  13. The arch of Costantino built in 312 AD

  14. History of Structural Engineering • From A.D. 500 to A.D.1500, structures that were built continued to employ the stone arch as the major structural forms. • Gothic Cathedrals • Roof was supported by flying buttresses

  15. Flying Buttress Cathedral from North East Chichester

  16. Flying Buttress Cathedral from South East Chichester

  17. History of Structural Engineering • Fifteenth and Sixteenth centuries are known as Renaissance. • Galileo (1564-1642) • Concept of force and moments • Robert Hooke (1635-1703) • Law of linear behavior of materials • Sir Isaac Newton (1642-1727) • Laws of motion • Leonhard Euler (1707-1783) • Buckling of columns • Palladio • introduced the use of truss

  18. GALILEO ROBERT HOOKE ISSAC NEWTON LEONHARD EULER PALLADIO

  19. History of Structural Engineering • Modern Era • Introduction of Iron • Industrial Revolution • First major structure built or iron was Severn River Bridge Coalbrookdale. • Suspension bridges • Thomas Telford’s Bridge over Menai Straits in Wales, • Brunel’s Clifton Bridge in Bristol, • Finley’s Bridge over Merrimack River in Newburyport, Massachusetts.

  20. Iron bridge, a cast-iron arch bridge built in 1779 across the River Severn near Coalbrookdale, Shropshire, England

  21. Thomas Telford built the suspension bridge in the middle in 1826. They had to destroy some of the castle to anchor it to the rock.

  22. Isambard Kingdom Brunel designs the Clifton Suspension Bridge at Bristol. Two hundred feet above the River Avon, the bridge is 700 feet long.

  23. History of Structural Engineering

  24. Forms of Structures Structural Forms Cables Arches Trusses Beams Surfaces Membranes Plates Shells

  25. Cables • Cables stretch well and are light, so they are useful in large structures. They only take tension stresses. • Cables can be crisscrossed and combined with surface materials to achieve light and large structures. • Examples of this technique are Suncoast Dome and Georgia Dome in the United States

  26. Hanger Tower Cable Cable Anchorage Road Way Golden Gate Bridge, San Francisco

  27. Cables • Grace Memorial Bridge over the Cooper River • Between Charleston, South Carolina (USA) and Mount Pleasant, South Carolina, stands the Grace Memorial Bridge.  • Completed in 1929, the cantilever steel structure has a main span of 1050 ft., or 320 m. and a total length of 3.6 miles or 5.79 Kilometers.  • A parallel bridge, with a similar design but a shorter main span, was built in 1966.  This allowed the old bridge to be converted to one-way traffic.

  28. Grace Memorial Bridge over the Cooper River

  29. Arches • An arch is a curved structure capable of spanning a space while supporting significant weight (e.g. a doorway in a stone wall). • The arch is significant because, in theory at least, it provides a structure which eliminates tensile stresses in spanning an open space. • All the forces are resolved into compressive stresses.

  30. Chinese Moon Bridge

  31. Made by Zhao1974 in Hebei Province, China. Built by the architect Li Chun from 595 to 605 AD. World's oldest fully-stone, open-spandrel, segmental arch bridge.

  32. Triangular Arch Round Arch Segmental Arch Rampant Round Arch Shoulder Flat Arch Three-Foiled Cusped Arch Lancet Arch Equilateral Pointed Arch

  33. Three-centered Arch Elliptical Arch Horseshoe Arch Inflexed Arch Ogee Arch Reverse Ogee Arch Tudor Arch Parabolic Arch

  34. Truss • In architecture and structural engineering, a truss is a structure comprising one or more triangular units constructed with straight slender members whose ends are connected at joints. • A plane truss is one where all the members and joints lie within a 2-dimensional plane, while a space truss has members and joints extending into 3 dimensions.

  35. Truss • All members are assumed in axial compression or tension. • Members are joined with the help of frictionless pins. • Loads are applied at joints only.

  36. Types of Trusses Common Truss It is characterized by its triangular shape. It is most often used for roof construction. Flat Truss It gets its name from its parallel top and bottom chords. It is often used for floor construction. Truncated Truss A combination of the two is a truncated truss. It is used in hip roof construction.

  37. Support structure under the Auckland Harbour Bridge.

  38. A Vierendeel bridge; note the lack of diagonal elements in the primary structure and the way bending loads are carried between elements

  39. Beams • A beam is a structural element that carries load primarily in bending (flexure). • Beams generally carry vertical gravitational forces but can also be used to carry horizontal loads (i.e. loads due to an earthquake or wind). • The loads carried by a beam are transferred to columns, walls, or girders, which then transfer the force to adjacent structural compression members.

  40. Beams • It requires only vertical supports at ends generally. • It is a compact structure. • It’s disadvantage is that it sometimes uses materials less economically than other structural systems.

  41. Surfaces Surfaces Membranes Plates Shells

  42. Membranes • Thin sheets of material • Resist applied loads by tension. • Examples are tents, sails, balloons etc

  43. Plates are flat surfaces that transfer loads by bending in a manner similar to beams. Plates

  44. Shells • Shell is rigid surface that transfers loads in two directions. • The primary difference between a plate and a shell is that the shell has curvature whereas the plate does not. TWA Flight Center, John F. Kennedy International Airport, New York.

  45. Materials Properties of Material Strength Deformation Characteristics Comp. Tension Resist. Strength to weight ratio Stiff Elastic Ductile

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