1. THOUGHTS ON STRUCTURAL ENGINEERING PRACTICE Presentation atUniversity of Texas and Purdue University November 2008 UĞUR ERSOY Bogazici University, Civil Engineering Dept. Istanbul - Turkey

2. The Mausoleum at Halicarnassus

3. The Temple of Artemis

4. Bozdogan Aqueduct (370 A.D.) Longest Waterline = 240 km, 149 mi From Stranca Mountains to İstanbul

8. St Sophia, İstanbulSt Sophia, İstanbul

9. Selimiye Mosque Edirne

10. CIVIL ENGINEERING PRIOR TO 18 th CENTURY: ARCHITECTURAL AND CIVIL ENGINEERING WORKS WERE DONE BY THE SAME CRAFTSMEN. I WOULD CALL THEM : “MASTERS” OR “BUILDERS”

11. MAIN TOOLS USED BY EARLY BUILDERS: -PAST EXPERIENCE -THEIR OWN EXPERIENCE -ENGINEERING INTUITION

12. TECHNOLOGY (From Greek) TECHNE = ART, CRAFT LOGOS = SCIENCE

13. SOMEONE HAS SAID THAT THE THEORY OF STRUCTURAL DESIGN IS BUILT BY ATTRIBUTING IMPOSSIBLE PROPERTIES TO NON-EXISTENT MATERIALS !!! Hardy Cross

20. HISTORY OF SCIENCE IS FULL OF BEAUTIFUL THEORIES, BUTCHERED BY SMALL UGLY FACTS ! Sir S. Thomas

24. 200 150 250 300 350 400 450

25. TENSILE STRENGTH OF CONCRETE: f ct = 4 (f ’ c ) 0.5 (In British units) TO EXPRESS THIS EQUATION IN “SI” UNITS, DIVIDE THE CONSTANT BY THE SQUARE ROOT OF 142. 4.0/(142) 0.5 = 0.33567 EQUATION EXPRESSING THE TENSILE STRENGTH AS A FUNCTION OF COMPRESSIVE STRENGTH BECOMES, f ct = 0.33567 (f ’ c ) 0.5 !!!!!!! ( SI units)

27. THE GREAT TRUTHS OF ENGINEERING ARE SIMPLE... AN ENDLESSLY COMPLEX PRESENTATION OF AN ENGINEERING FACT INDICATES COMPLICATION IN THE BRAIN OF THE PROPOUNDER RATHER THAN COMPLEXITY OF NATURE. Hardy Cross

28. Building Model ANALYSİS FILTER DECISION

29. THE ASSEMLY CAN NEVER REPLACE THE BRAIN THAT HAS CREATED IT ! MACHINES,METHODS AND SYSTEMS CANNOT BE A SUBSTITUTE FOR MEN Hardy Cross

30. METHODS OF ANALYSIS ARE OFTEN VERY FORMALISTIC, LIKE A SAUSAGE GRINDER. IF CERTAIN NUMERICAL DATA ARE FED INTO ONE END OF THE ANALYSIS AND A CRANK IS TURNED, A LOT OF LITTLE SAUSAGES (moments, shears, deformation etc.) COME INEVITABLY OUT OF THE OTHER END OF THE MACHINE. IT WORKS QUITE SMOOTHLY; IN FACT IT WORKS WITH DECEIVING SMOOTHNESS. BECAUSE THE SAUSAGES SEEM UNIFORM AND REGULAR, IT IS OFTEN ASSUMED THAT THE MEAT CAN NOT BE SPOILED. Hardy Cross

31. IT IS IMPORTANT TO KNOW THE LIMITATIONS OF KNOWLEDGE AND ASK QUESTIONS, SIMPLE QUESTIONS, THAT MAY OPEN UP HOLES THROUGH WHICH LIGHT CAN FILTER INTO OUR DARK ROOMS. Hardy Cross

34. PLASTIC HINGE: ELASTO-PLASTIC BEHAVIOUR ROTATION UNDER CONSTANT MOMENT M p M p = SECTION CAPACITY

37. M d, depends on M r

39. (Revised) (Linear Analysis) IF

41. Yielding in column 1 Elastic Analysis

44. o1 o1o1 T o2 1

46. Wrong detailing Better detailing