Abstract
Robust optimization aims at producing designs which are less sensitive to uncertainties. Risk optimization looks for designs with optimal balance between performance and safety. In spite of the different objectives, robust and risk-based formulations have strong similitude, which has not been thoroughly explored before. This paper explores the similarities and differences between these formulations. It is shown that the alpha factors, which are employed in compromise solutions in robust optimization, are equivalent to the costs of failure in risk-based optimization. Moreover, it is shown that the robust objective function is often non-convex, with results being given by (often arbitrary) design constraints. In some sense, the robust objective function lacks objectiveness, with results largely dependent on arbitrary normalizing constants. On the other hand, when there is a critical limit to performance, which characterizes system failure, and when costs of failure can be defined, the risk-based optimization yields consistent results, and no normalizing constants are needed.
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References
Aktas E, Moses F, Ghosn M (2001) Cost and safety optimization of structural design specifications. Reliab Eng Syst Saf 73:205–212
Ang AHS, Tang WH (2007) Probability concepts in engineering: emphasis on applications to civil and environmental engineering. 2nd ed. Wiley
Aoues Y, Chateauneuf A (2010) Benchmark study of numerical methods for reliability-based design optimization. Struct Multidiscip Optim 41:277–294
Augusti G, Ciampoli M (2008) Performance-based design in risk assessment and reduction. Probab Eng Mech 23:496–508
Barbato M, Petrini F, Unnikrishnan VU, Ciampoli M (2013) Performance-Based Hurricane Engineering (PBHE) framework. Struct Saf 45:24–35
Beck AT, Gomes WJS (2012) A comparison of deterministic, reliability-based and risk-based structural optimization under uncertainty. Probab Eng Mech 28:18–29
Beck AT, Verzenhassi CC (2008) Risk optimization of a steel frame communications tower subject to tornado winds. Lat Am J Solids Struct 5:187–203
Beck AT, Gomes WJS, Bazán FAV (2012) On the robustness of structural risk optimization with respect to epistemic uncertainties. Int J Uncertain Quantif 2:1–20
Beck AT, Kougioumtzoglou IA, Santos KR (2014) Optimal performance-based design of non-linear stochastic dynamical systems. Eng Struct78:145–153. doi:10.1016/j.engstruct.2014.07.047
Beyer HG, Sendhoff B (2007) Robust optimization—a comprehensive survey. Comput Methods Appl Mech Eng 196:3190–3218
Birge L (1997) Introduction to stochastic programming. Springer, New York
Bucher C, Frangopol DM (2006) Optimization of lifetime maintenance strategies for deteriorating structures considering probabilities of violating safety, condition, and cost thresholds. Probab Eng Mech 21:1–8
Chen X, Hasselman TK, Neill DJ (1997) Reliability based structural design optimization for practical applications. In: Proc. 38th AIAA SDM Conf. (held in Kissimmee), AIAA-97-1403
Ciampoli M, Petrini F (2012) Performance-based Aeolian risk assessment and reduction for tall buildings. Probab Eng Mech 28:75–84
Ciampoli M, Petrini F, Augusti G (2011) Performance-based wind engineering: towards a general procedure. Struct Saf 33:367–378
Dai Z, Mourelatos ZP (2003) Robust design using preference aggregation methods. In: ASME 2003 Design Engineering Technical Conferences and Computer and Information in Engineering Conference, Chicago
Das I, Dennis JE (1997) A closer look at drawbacks of minimizing weighted sums of objectives for Pareto set generation in multi-criteria optimization problems. Struct Optim 14:63–69
Enevoldsen I, Sorensen JD (1994) Reliability-based optimization in structural engineering. Struct Saf 15:169–196
Frangopol DM, Maute K (2003) Life-cycle reliability-based optimization of civil and aerospace structures. Comput Struct 81(7):397–410
Ghobarah A (2001) Performance-based design in earthquake engineering: state of development. Eng Struct 23:878–884
Gomes WJS, Beck AT (2013) Global structural optimization considering expected consequences of failure and using ANN surrogates. Comput Struct 126:56–68. doi:10.1016/j.compstruc.2012.10.013
Gomes WJS, Beck AT (2014a) Optimal inspection and design of onshore pipelines under external corrosion process. Struct Saf 47:48–58. doi:10.1016/j.strusafe.2013.11.001
Gomes WJS, Beck AT (2014b) Optimal inspection planning and repair under random crack propagation. Eng Struct 69:285–296. doi:10.1016/j.engstruct.2014.03.021
Gomes WJS, Beck AT, Haukaas T (2013) Optimal inspection planning for onshore pipelines subject to external corrosion. Reliab Eng Syst Saf 118:18–27. doi:10.1016/j.ress.2013.04.011
Haukaas T (2008) Unified reliability and design optimization for earthquake engineering. Probab Eng Mech 23:471–481
Kall P, Wallace SW (1994) Stochastic programming, Wiley
Lopez RH, Beck AT (2012) Reliability-based design optimization strategies based on FORM: a review. J Braz Soc Mech Sci Eng 34:506–514
Marano GC, Sgobba S, Greco R, Mezzina M (2008) Robust optimum design of tuned mass dampers devices in random vibrations mitigation. J Sound Vib 313:472–492
Marano GC, Greco R, Sgobba S (2010) A comparison between different robust optimum design approaches: application to tuned mass dampers. Probab Eng Mech 25:108–118
Melchers RE (1999) Structural reliability analysis and prediction, 2nd edn. Wiley, NY
Mínguez R, Castillo E (2009) Reliability-based optimization in engineering using decomposition techniques and FORMS. Struct Saf 31:214–223
Möller B, Beer M (2004) Fuzzy randomness - uncertainty in civil engineering and computational mechanics, Springer
Möller O, Foschi RO, Quiroz LM, Rubinstein M (2009) Structural optimization for performance-based design in earthquake engineering: applications of neural networks. Struct Saf 31:490–499
Papadopoulos V, Lagaros ND (2009) Vulnerability-based robust design optimization of imperfect shell structures. Struct Saf 31:475–482
Rackwitz R (2002) Optimization and risk acceptability based on the life quality index. Struct Saf 24:297–331
Rackwitz R (2004) Life quality index revisited. Struct Saf 26:443–451
Ritto T, Lopez RH, Sampaio R, Cursi ES (2011) Robust optimization of a flexible rotor-bearing system using the Campbell diagram. Eng Optim 43:77–96
Roy BJ, Chakraborty S, Mihsra SK (2014) Robust optimum design of base isolation system in seismic vibration control of structures under uncertain bounded system parameters. J Vib Control 20:786–800
Schuëller GI, Jensen HA (2009) Computational methods in optimization considering uncertainties—an overview. Comput Methods Appl Mech Eng 198:2–13
Silva M, Tortorelli D, Norato J, Ha C, Bae H (2010) Component and system reliability-based topology optimization using a single-loop method. Struct Multidiscip Optim 41:87–106
Soltani M, Corotis RB (1988) Failure cost design of structural systems. Struct Saf 5(4):239–252
Streicher H, Rackwitz R (2004) Time-variant reliability-oriented structural optimization and a renewal model for life-cycle costing. Probab Eng Mech 19:171–183
Structural Engineers Association of California (1995) Vision 2000, performance based seismic engineering of buildings, vols. I and II: conceptual framework. Structural Engineers Association of California, Sacramento
Torii AJ, Lopez RH, Biondini F (2011) An approach to reliability-based shape and topology optimization of truss structures. Eng Optim 44:37–53
Tubaldi E, Barbato M, Ghazizadeh S (2012) A probabilistic performance-based risk assessment approach for seismic pounding with efficient application to linear systems. Struct Saf 36–37:14–22
Valdebenito MA, Schueller GI (2010) A survey on approaches for reliability-based optimization. Struct Multidiscip Optim 42:645–663
Zang C, Friswell MI, Mottershead JE (2005) A review of robust optimal design and its application in dynamics. Comput Struct 83:315–326
Acknowledgments
Sponsorship of this research project by the São Paulo State Foundation for Research - FAPESP (grant number 2012/21357-1) and by the National Council for Research and Development - CNPq (grant number 303749/2012-1) is greatly acknowledged. Comments by the anonymous reviewers have significantly improved the paper and are also greatly acknowledged.
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Beck, A.T., Gomes, W.J.S., Lopez, R.H. et al. A comparison between robust and risk-based optimization under uncertainty. Struct Multidisc Optim 52, 479–492 (2015). https://doi.org/10.1007/s00158-015-1253-9
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DOI: https://doi.org/10.1007/s00158-015-1253-9