2. BALLOON + JET ENGINE = QUALITATIVELY NEW TRANSPORTATION MEAN ??????? NO !

3. PARTIAL FACTORS METHOD + COMPUTERS = QUALITATIVELY NEW STRUCTURAL RELIABILITY ASSESSMENT CONCEPT ????? NO ! such as EC or LRFD COMPUTERS

4. PROBABILISTIC METHOD (such as SBRA) + COMPUTERS = QUALITATIVELY NEW STRUCTURAL RELIABILITY ASSESSMENT CONCEPT ??? YES!

5. 4 SBRA Input variables are expressed by bounded non-parametric histograms. Reliability function is analyzed by the designer using Monte Carlo method. Reliability is expressed by P f < P d, where P f is the probability of failure and P d is the target probability given in codes. P f = Σ / Σ < P d R – S = 0

6. 5 Computer Program AntHill  for Windows

7. 6 What is the Load Duration Curve (LDC)? Loading History ‚Sorted‘ History LDC

8. 7 Load Duration Curves, LDC, and corresponding Histograms Dead Short Long Wind

9. 8 Two - and More -Component Load Duration Curves Wind Rosette Wind Directon and Wind Velocity

10. 9 One-component Load Effect Combination Analysis using Monte Carlo technique and ResCom computer program

11. 10

12. 11

13. 12

14. Probability of Failure P f LRFD SBRA EC3 0.001 0. 0001 0. 00001 0. 000001 estimate

15. 14

16. 15

17. 16 SBRA Dead + Long-Lasting Dead +Short-Lasting

18. 17 (a) N (b) N, M x (c) N, M x, M y

19. 18 Combination of multi- component load effects Each Load Effect is expressed, for example, by N, M x and M y x - x N, M x, M y

20. 19 S Load Effect Combination S R - S = 0 Resistance R R

21. 20 Definition of the Resistance P  „Reference Level“ ??? USEABILITY

22. 21 Reference levels a) Onset of yielding b) Tolerable permanent deflection Non-tolerable permanent deflection d) Formation of the full plastic hinge USEFULLNESS c) Limited Damage

23. 22 Probability of Failure CASE Reference level defined by Steel beamProbability of Failure (a) Onset of yieldingElastic range 0.000293 < P d (b) Tolerable permanent deformation Acceptable permanent deformation 0.000044 < P d (c )Tolerable DamageTo be repaired or replaced 0.000015 < P perf (d)CollapseDisposal 0.000008 < ????

24. Variabilities of yield stress, cross-section area, initial eccentricity and effect of residual stresses are expressed by bounded histograms: Cross-section area  A var Initial eccentricity  e o Effect of residual stresses  Res var Yield stress  f y Column Resistance: Variables

25. 24 Slenderness ratio Stress (N.mm -2 ) Variables: f y, e o, A,..

26. 25 Target Probability P d according to CSN 73 1401-1998

27. 26 Safety Assessment Using the Probabilistic Simulation-Based Reliability Assessment Concept 1

28. 27 Target Probability P d according to CSN 73 1401-1998

29. 28 Steel beam exposed to a combination of loads Load Duration Curves and corresponding Histograms

30. 29 Dimensioning of a Beam

31. 30 Safety check of the steel beam (P f,saf = 0,00003 < P d,saf = 0,00007)

32. 31 Bar exposed to Tension and Compression

33. 32 Frame containing leaning columns

34. 33 Serviceability Assessment Using the Probabilistic Simulation-Based Reliability Assessment Concept 1

35. 34

36. 35 Basic alternatives of serviceability reliability conditions (Cases 1 to 25)

37. 36 Target Probability P d according to CSN 73 1401-1998

38. 37 Steel beam exposed to a combination of loads Load Duration Curves and corresponding Histograms

39. 38 Serviceability Assessment of a steel beam Application of a ‘blurred’ serviceability limiting value

40. 39 Frame containing leaning columns SF= DEL tol - DEL ( DEL tol = 30 mm ) Serviceability assessment P f = 0.037 < P d = 0.070 O.K. DEL EXAMPLE 2

41. 40 Durability Assessment Using the Probabilistic Simulation-Based Reliability Assessment Concept 1

42. 41

43. 42 1 MIPS 5  10 2 MIPS > 10 GIPS PC XT PENTIUM Hypercomputers and more

44. 43 How will look like the new generation of specifications and design tools?

45. 44 Impact of computer technology Reengineering of the design procedure Application of powerful simulation techniques in designer‘s work From Components to Systems New generation of specifications, application of databases and information technology Education of designers: From deterministic to probabilistic ‘way of thinking‘ SUMMARY AND CONCLUSIONS