Documents disponibles écrits par cet auteur

Efficient spreadsheet algorithm for first-order reliability method / B. K. Low in Journal of engineering mechanics, Vol. 133 N°12 (Decembre 2007) 

Public ISBD [article]  in Journal of engineering mechanics > Vol. 133 N°12 (Decembre 2007) . - pp.1378–1387. Titre : Efficient spreadsheet algorithm for first-order reliability method Type de document : texte imprimé Auteurs : B. K. Low, Auteur ; Wilson H. Tang, Auteur Année de publication : 2007 Article en page(s) : pp.1378–1387. Note générale : Mécanique appliquée Langues : Anglais (eng) Mots-clés : Probability  Reliability  Correlation  Optimization  Computer  software  Computation Résumé : A new spreadsheet-cell-object-oriented algorithm for the first-order reliability method is proposed and illustrated for cases with correlated nonnormals and explicit and implicit performance functions. The new approach differs from the writers earlier algorithm by obviating the need for computations of equivalent normal means and equivalent normal standard deviations. It obtains the solution faster and is more efficient, robust, and succinct. Other advantages include ease of initialization prior to constrained optimization, ease of randomization of initial values for checking robustness, and fewer required optimization constraints during spreadsheet-automated search for the design point. Two cases with implicit performance functions, namely an asymmetrically loaded beam on Winkler medium and a strut with complex supports are analyzed using the new approach and discussed. Comparisons are also made between the proposed approach and that based on Rosenblatt transformation. ISSN : 0733-9399 En ligne : http://ascelibrary.org/action/showAbstract?page=1378&volume=133&issue=12&journal [...] [article] Efficient spreadsheet algorithm for first-order reliability method [texte imprimé] / B. K. Low, Auteur ; Wilson H. Tang, Auteur . - 2007 . - pp.1378–1387. Mécanique appliquée Langues : Anglais (eng) in Journal of engineering mechanics > Vol. 133 N°12 (Decembre 2007) . - pp.1378–1387. Mots-clés : Probability  Reliability  Correlation  Optimization  Computer  software  Computation Résumé : A new spreadsheet-cell-object-oriented algorithm for the first-order reliability method is proposed and illustrated for cases with correlated nonnormals and explicit and implicit performance functions. The new approach differs from the writers earlier algorithm by obviating the need for computations of equivalent normal means and equivalent normal standard deviations. It obtains the solution faster and is more efficient, robust, and succinct. Other advantages include ease of initialization prior to constrained optimization, ease of randomization of initial values for checking robustness, and fewer required optimization constraints during spreadsheet-automated search for the design point. Two cases with implicit performance functions, namely an asymmetrically loaded beam on Winkler medium and a strut with complex supports are analyzed using the new approach and discussed. Comparisons are also made between the proposed approach and that based on Rosenblatt transformation. ISSN : 0733-9399 En ligne : http://ascelibrary.org/action/showAbstract?page=1378&volume=133&issue=12&journal [...]

Efficient spreadsheet algorithm for first-order reliability method / B. K. Low in Journal of engineering mechanics, Vol. 133 N°11 (Novembre 2007) 

Public ISBD [article]  in Journal of engineering mechanics > Vol. 133 N°11 (Novembre 2007) . - pp.1378–1387. Titre : Efficient spreadsheet algorithm for first-order reliability method Type de document : texte imprimé Auteurs : B. K. Low, Auteur ; Wilson H. Tang, Auteur Année de publication : 2007 Article en page(s) : pp.1378–1387. Note générale : Mécanique appliquée Langues : Anglais (eng) Mots-clés : Probability  Reliability  Correlation  Optimization  Computer  software  Computation Résumé : A new spreadsheet-cell-object-oriented algorithm for the first-order reliability method is proposed and illustrated for cases with correlated nonnormals and explicit and implicit performance functions. The new approach differs from the writers earlier algorithm by obviating the need for computations of equivalent normal means and equivalent normal standard deviations. It obtains the solution faster and is more efficient, robust, and succinct. Other advantages include ease of initialization prior to constrained optimization, ease of randomization of initial values for checking robustness, and fewer required optimization constraints during spreadsheet-automated search for the design point. Two cases with implicit performance functions, namely an asymmetrically loaded beam on Winkler medium and a strut with complex supports are analyzed using the new approach and discussed. Comparisons are also made between the proposed approach and that based on Rosenblatt transformation. ISSN : 0733-9399 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%290733-9399%282007%29133%3A12%281 [...] [article] Efficient spreadsheet algorithm for first-order reliability method [texte imprimé] / B. K. Low, Auteur ; Wilson H. Tang, Auteur . - 2007 . - pp.1378–1387. Mécanique appliquée Langues : Anglais (eng) in Journal of engineering mechanics > Vol. 133 N°11 (Novembre 2007) . - pp.1378–1387. Mots-clés : Probability  Reliability  Correlation  Optimization  Computer  software  Computation Résumé : A new spreadsheet-cell-object-oriented algorithm for the first-order reliability method is proposed and illustrated for cases with correlated nonnormals and explicit and implicit performance functions. The new approach differs from the writers earlier algorithm by obviating the need for computations of equivalent normal means and equivalent normal standard deviations. It obtains the solution faster and is more efficient, robust, and succinct. Other advantages include ease of initialization prior to constrained optimization, ease of randomization of initial values for checking robustness, and fewer required optimization constraints during spreadsheet-automated search for the design point. Two cases with implicit performance functions, namely an asymmetrically loaded beam on Winkler medium and a strut with complex supports are analyzed using the new approach and discussed. Comparisons are also made between the proposed approach and that based on Rosenblatt transformation. ISSN : 0733-9399 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%290733-9399%282007%29133%3A12%281 [...]

Reliability analysis of laterally loaded piles involving nonlinear soil and pile behavior / C. L. Chan in Journal of geotechnical and geoenvironmental engineering, Vol. 135 N°3 (Mars 2009) 

Public ISBD [article]  in Journal of geotechnical and geoenvironmental engineering > Vol. 135 N°3 (Mars 2009) . - pp. 431–443 Titre : Reliability analysis of laterally loaded piles involving nonlinear soil and pile behavior Type de document : texte imprimé Auteurs : C. L. Chan, Auteur ; B. K. Low, Auteur Année de publication : 2009 Article en page(s) : pp. 431–443 Note générale : Geotechnical and geoenvironmental engineering Langues : Anglais (eng) Mots-clés : Correlation  Design  Failure  modes  Limit  states  Monte  Carlo  method  Nonlinear  analysis  Optimization  Pile  lateral  loads  Reliability  Soil  properties Résumé : An alternative approach of analyzing laterally loaded piles in the ubiquitous spreadsheet platform is presented. The numerical procedure couples nonlinear pile flexural rigidity (EpIp) with nonlinear p-y analysis. The deterministic study is then extended to carry out reliability analysis, which reflects the uncertainties and correlation structure of the underlying parameters. The reliability index is evaluated based on the alternative intuitive perspective of an expanding equivalent ellipsoid in the original space of the random variables. This paper investigates two modes of failure: deflection and bending moment, and considers non-normal random variables. Spatial variability of the soil medium is accounted for by incorporating an autocorrelation model. The spreadsheet-based reliability approach can also be coupled with stand-alone programs via the response surface method. The probabilities of failure inferred from reliability indices agree well with Monte Carlo simulations. Simple reliability-based design is demonstrated, in which the appropriate pile section or length that satisfies target reliability in one or more limit states is sought. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%291090-0241%282009%29135%3A3%2843 [...] [article] Reliability analysis of laterally loaded piles involving nonlinear soil and pile behavior [texte imprimé] / C. L. Chan, Auteur ; B. K. Low, Auteur . - 2009 . - pp. 431–443. Geotechnical and geoenvironmental engineering Langues : Anglais (eng) in Journal of geotechnical and geoenvironmental engineering > Vol. 135 N°3 (Mars 2009) . - pp. 431–443 Mots-clés : Correlation  Design  Failure  modes  Limit  states  Monte  Carlo  method  Nonlinear  analysis  Optimization  Pile  lateral  loads  Reliability  Soil  properties Résumé : An alternative approach of analyzing laterally loaded piles in the ubiquitous spreadsheet platform is presented. The numerical procedure couples nonlinear pile flexural rigidity (EpIp) with nonlinear p-y analysis. The deterministic study is then extended to carry out reliability analysis, which reflects the uncertainties and correlation structure of the underlying parameters. The reliability index is evaluated based on the alternative intuitive perspective of an expanding equivalent ellipsoid in the original space of the random variables. This paper investigates two modes of failure: deflection and bending moment, and considers non-normal random variables. Spatial variability of the soil medium is accounted for by incorporating an autocorrelation model. The spreadsheet-based reliability approach can also be coupled with stand-alone programs via the response surface method. The probabilities of failure inferred from reliability indices agree well with Monte Carlo simulations. Simple reliability-based design is demonstrated, in which the appropriate pile section or length that satisfies target reliability in one or more limit states is sought. En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%291090-0241%282009%29135%3A3%2843 [...]