Advance first order second moment (AFOSM) method for single reservoir operation reliability analysis: a case study

The current intersection sight distance values on a roundabout provided by ASSHTO and other worldwide guidelines are based on deterministic methods considering only single variables as the design inputs. However, most of the input design variables such as entering speed and the deceleration rate are random variables which are stochastic in nature. Therefore, this study proposes a reliability analysis approach to add uncertainty to the current deterministic models. Two different reliability approaches; the first order second moment and advanced first order second moment are presented in this paper. These approaches rely on the normal distribution of the random variables using the mean, variance and the covariance of the probability distribution of each variable rather than the single deterministic values. Results show that the AFOSM reliability methodology provides a more conservative outcome which ensures a greater safety margin comparing to FOSM which appears to be a more efficient and robust methodology.

Download Full-text

Reliability analysis of truck escape ramp design

10.32920/ryerson.14638902 ◽

2021 ◽

Author(s):

Kaitlyn Ann Greto

Keyword(s):

Reliability Analysis ◽

Safety Margin ◽

Rolling Resistance ◽

Second Moment ◽

First Order ◽

Stopping Distance ◽

Design Variables ◽

Reliability Method ◽

First Order Second Moment ◽

Design Speed

The truck escape ramp design presented by the Transportation Association of Canada is based on deterministic values of the design variables which include the required stopping distance, design speed, rolling resistance, and grade. Currently, a reliability analysis of the design of truck escape ramps does not exist. This report presents two methods used to analyze the reliability of truck escape ramp design; the first order second moment reliability method and the advanced first order second moment reliability method. These methods do not rely on deterministic values rather the mean and variance (moments) of each random variable’s probability distribution. Each reliability method was used to analyze truck escape ramps with one grade and two grades, for a total of four cases. The results of each case are provided and discussed along with an application to two existing truck escape ramps. The results show that the advanced first order second moment reliability method ensures more accurate results as well as a larger safety margin in comparison to the first order second moment method due to the nature of the methodology itself which considers design points.

Download Full-text

Reliability Analysis Approach For Intersection Sight Distance Of A Symmetrical Single-Lane Roundabout

10.32920/ryerson.14643735.v1 ◽

2021 ◽

Author(s):

Paria Sarshar

Keyword(s):

Reliability Analysis ◽

Safety Margin ◽

Random Variables ◽

Analysis Approach ◽

Deterministic Models ◽

Second Moment ◽

First Order ◽

Sight Distance ◽

Design Variables ◽

First Order Second Moment

The current intersection sight distance values on a roundabout provided by ASSHTO and other worldwide guidelines are based on deterministic methods considering only single variables as the design inputs. However, most of the input design variables such as entering speed and the deceleration rate are random variables which are stochastic in nature. Therefore, this study proposes a reliability analysis approach to add uncertainty to the current deterministic models. Two different reliability approaches; the first order second moment and advanced first order second moment are presented in this paper. These approaches rely on the normal distribution of the random variables using the mean, variance and the covariance of the probability distribution of each variable rather than the single deterministic values. Results show that the AFOSM reliability methodology provides a more conservative outcome which ensures a greater safety margin comparing to FOSM which appears to be a more efficient and robust methodology.

Download Full-text

Reliability Analysis of Wood-Plastic Structural Plates

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.101-102.1074 ◽

2011 ◽

Vol 101-102 ◽

pp. 1074-1077

Author(s):

Gui Wen Yu

Keyword(s):

Structural Material ◽

Reliability Analysis ◽

Modulus Of Elasticity ◽

Moment Method ◽

Bending Strength ◽

Second Moment ◽

First Order ◽

First Order Second Moment ◽

Second Moment Method

The wood-plastic structural plates, which were made of polyethylene (PE) and poplar powder, were used in decking as a structural material. It is of great significance to analyze the material reliability for the safety in service. In this paper, the modulus of elasticity and static bending strength of specimens were obtained through test, the first order second moment method (FOSM) was used to analyze the reliability of the wood-plastic structural plates. The result showed that the wood-plastic structural plates have a better reliability, and the reliability of the wood-plastic structural plates was related to the thickness of the specimens.

Download Full-text

Research on slope reliability analysis using multi-kernel relevance vector machine and advanced first-order second-moment method

Engineering With Computers ◽

10.1007/s00366-021-01331-9 ◽

2021 ◽

Author(s):

Chun hui Ma ◽

Jie Yang ◽

Lin Cheng ◽

Li Ran

Keyword(s):

Reliability Analysis ◽

Moment Method ◽

Relevance Vector Machine ◽

Second Moment ◽

First Order ◽

First Order Second Moment ◽

Second Moment Method

Download Full-text

Random polar sampling technique for the reliability analysis of submarine pressure hull

Journal of Naval Architecture and Marine Engineering ◽

10.3329/jname.v1i1.2036 ◽

1970 ◽

Vol 1 (1) ◽

pp. 26-34

Author(s):

P Radha ◽

K Rajagopalan

Keyword(s):

Monte Carlo Simulation ◽

Monte Carlo ◽

Reliability Analysis ◽

Moment Method ◽

Sampling Technique ◽

Latin Hypercube ◽

Second Moment ◽

First Order ◽

First Order Second Moment ◽

Second Moment Method

Reliability analysis is essential to reduce the structural system failures to an acceptance level. In this paper, a quasi-Monte Carlo Simulation method called âRandom Polar Sampling Technique' (RPST) has been described for the reliability analysis of ring stiffened shell structure, in which the combinations of variates are obtained using a polar sampling of Latin hypercube sampled values. An efficient computer program coded in C++ has been developed for use with the RPST. Reliability analysis of internally ring stiffened submarine pressure hull has been described as an illustration and the results are compared with those given by First Order Second Moment method (FOSM), Advanced First Order Second Moment method (AFOSM) and Monte-Carlo Simulation methods. Keywords: Random Polar Sampling Technique, Reliability, Ring stiffened shells, Submarine pressure hull, Latin Hypercube Samples. Â doi: 10.3329/jname.v1i1.2036 Journal of Naval Architecture and Marine Engineering 1(2004) 26-34

Download Full-text

Reliability analysis of truck escape ramp design

10.32920/ryerson.14638902.v1 ◽

2021 ◽

Author(s):

Kaitlyn Ann Greto

Keyword(s):

Reliability Analysis ◽

Safety Margin ◽

Rolling Resistance ◽

Second Moment ◽

First Order ◽

Stopping Distance ◽

Design Variables ◽

Reliability Method ◽

First Order Second Moment ◽

Design Speed

The truck escape ramp design presented by the Transportation Association of Canada is based on deterministic values of the design variables which include the required stopping distance, design speed, rolling resistance, and grade. Currently, a reliability analysis of the design of truck escape ramps does not exist. This report presents two methods used to analyze the reliability of truck escape ramp design; the first order second moment reliability method and the advanced first order second moment reliability method. These methods do not rely on deterministic values rather the mean and variance (moments) of each random variable’s probability distribution. Each reliability method was used to analyze truck escape ramps with one grade and two grades, for a total of four cases. The results of each case are provided and discussed along with an application to two existing truck escape ramps. The results show that the advanced first order second moment reliability method ensures more accurate results as well as a larger safety margin in comparison to the first order second moment method due to the nature of the methodology itself which considers design points.

Download Full-text