Fire safety assessment and optimal design of passive fire protection for offshore structures

Shetty, N K; Soares, C. Guedes; Thoft‐Christensen, Palle; Jensen, F.

doi:10.1016/s0951-8320(97)00124-5

Cited by 33 publications

(19 citation statements)

References 2 publications

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“…Most RBDO approaches are based on FORM and RBDO including SORM appears less freqently. However, RBDO using SORM is discussed already in the paper by Shetty et al (1998), where fire safety of offshore structures was optimized. Another early paper on RBDO using SORM is by Choi et al (2001).…”

Section: Pr[h(y ) < 0] ≈ (−β Hl )mentioning

confidence: 99%

Reliability-based design optimization using SORM and SQP

Strömberg

2017

Struct Multidisc Optim

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In this work a second order approach for reliabilitybased design optimization (RBDO) with mixtures of uncorrelated non-Gaussian variables is derived by applying second order reliability methods (SORM) and sequential quadratic programming (SQP). The derivation is performed by introducing intermediate variables defined by the incremental iso-probabilistic transformation at the most probable point (MPP). By using these variables in the Taylor expansions of the constraints, a corresponding general first order reliability method (FORM) based quadratic programming (QP) problem is formulated and solved in the standard normal space. The MPP is found in the physical space in the metric of Hasofer-Lind by using a Newton algorithm, where the efficiency of the Newton method is obtained by introducing an inexact Jacobian and a line-search of Armijo type. The FORM-based SQP approach is then corrected by applying four SORM approaches: Breitung, Hohenbichler, Tvedt and a recent suggested formula. The proposed SORMbased SQP approach for RBDO is accurate, efficient and robust. This is demonstrated by solving several established benchmarks, with values on the target of reliability that are considerable higher than what is commonly used, for mixtures of five different distributions (normal, lognormal, Gumbel, gamma and Weibull). Established benchmarks are also generalized in order to study problems with large number of variables and several constraints. shown that the proposed approach efficiently solves a problem with 300 variables and 240 constraints within less than 20 CPU minutes on a laptop. Finally, a most well-know deterministic benchmark of a welded beam is treated as a RBDO problem using the proposed SORM-based SQP approach.

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Section: Pr[h(y ) < 0] ≈ (−β Hl )mentioning

confidence: 99%

Reliability-based design optimization using SORM and SQP

Strömberg

2017

Struct Multidisc Optim

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“…By using first-and second-order reliability methods (FORM/SORM), a probabilistic approach to fire safety assessment and optimal design of passive fire protection on offshore topside structures is developed by Shetty et al (1998). Hamilton (2011) Lange et al (2014 adapted the earthquake framework, which is developed by The Pacific Earthquake Engineering Research (PEER) to structural fire engineering.…”

Section: Introductionmentioning

confidence: 99%

Reliability risk assessment in high rise buildings in case of fire

Selamet

Akcan²

2015

Proceedings of the Second International Conference on Performance-Based and Life-Cycle Structural Engineering (PLSE 2015)

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The practice of structural fire safety engineering remains to be case-specific and the estimation of fire resistance of structures is mostly deterministic. Many researchers in structural fire engineering utilize the performancebased design method but these studies do not include the inherent uncertainties in both the demand and capacity. This paper investigates the structural fire reliability of tall buildings based on the framework used for earthquake hazard by the Pacific Earthquake Engineering Research (PEER) and Eurocode. The financial district of Istanbul in Turkey is taken as a case study for this research. Parameters such as building type and height, structural system, number of floors, floor area, number of elevators and stairs, the use of fire suppression systems, evacuation routes are provided by the municipalities in order to develop a probabilistic methodology to estimate the fire safety of these structures. The analysis is conducted by estimating the intensity or the hazard curve as described by PEER framework. The hazard domain includes random variables such as the fire load, the opening factor, the fire duration and the maximum fire temperature. The findings of this research will provide essential information on the fire safety risk of each tall building in a densely populated financial district. It will allow the municipalities and fire brigades to have a probabilistic risk assessment of these structures and develop evacuation and human rescue plans accordingly in case of a fire hazard. Further, this research will provide useful data to insurance companies to estimate fire hazard insurance premiums. KEYWORDSStructures in fire, structural fire safety and reliability, performance based design, probabilistic analysis.

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“…These include Beck (1985), who studied the reliability of structural steel members exposed to fires; Shetty et al (1998) who applied reliability analysis to assess the fire safety of offshore structures; Teixeira and Soares (2006) who estimated the reliability of load bearing steel plates subjected to localized heat loads; and Vaidogas and Juocevicius (2008), who considered the reliability analysis of a timber structure exposed to fire.…”

Section: Introductionmentioning

confidence: 99%

Reliability Analysis of RC Beams Exposed to Fire

Eamon

Jensen

2013

J. Struct. Eng.

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A procedure for conducting reliability analysis of reinforced concrete beams subjected to a fire load is presented. This involves identifying relevant load combinations, specifying critical load and resistance random variables, and establishing a high-temperature performance model for beam capacity. Based on the procedure, an initial reliability analysis is conducted using currently available data. Significant load random variables are taken to be dead load, sustained live load, and fire temperature. Resistance is in terms of moment capacity, with random variables taken as steel yield strength, concrete compressive strength, placement of reinforcement, beam width, and thermal diffusivity. A semi-empirical model is used to estimate beam moment capacity as a function of fire exposure time, which is calibrated to experimental data available in the literature.The effect of various beam parameters were considered, including cover, beam width, aggregate type, compressive strength, dead to live load ratio, reinforcement ratio, support conditions, mean fire temperature, and other parameters. Using the suggested procedure, reliability was estimated from zero to four hours of fire exposure using Monte Carlo simulation. It was found that reliability decreased nonlinearly as a function of time, while the most significant parameters were concrete cover; span/depth ratio when axial restraints are present, mean fire temperature; and support conditions.

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Fire safety assessment and optimal design of passive fire protection for offshore structures

Cited by 33 publications

References 2 publications

Reliability-based design optimization using SORM and SQP

Reliability-based design optimization using SORM and SQP

Reliability risk assessment in high rise buildings in case of fire

Reliability Analysis of RC Beams Exposed to Fire

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