Refined first-order reliability method using cross-entropy optimization method

2018 ◽  
Vol 35 (4) ◽  
pp. 1507-1519 ◽  
Author(s):  
Hamed Ghohani Arab ◽  
Mohsen Rashki ◽  
Mehdi Rostamian ◽  
Alireza Ghavidel ◽  
Hossein Shahraki ◽  
...  
Keyword(s):  
Optimization Method ◽  
Cross Entropy ◽  
First Order Reliability Method ◽  
First Order ◽  
Entropy Optimization ◽  
Reliability Method

An accuracy analysis method for first-order reliability method

2018 ◽  
Vol 233 (12) ◽  
pp. 4319-4327 ◽  
Author(s):  
Zhenzhong Chen ◽  
Zihao Wu ◽  
Xiaoke Li ◽  
Ge Chen ◽  
Guangfeng Chen ◽  
...  
Keyword(s):  
Structural Reliability ◽  
Nonlinear Problems ◽  
Accuracy Analysis ◽  
Analysis Method ◽  
First Order Reliability Method ◽  
First Order ◽  
Reliability Level ◽  
Reliability Method ◽  
Value Range ◽  
Crashworthiness Design

The first-order reliability method is widely used for structural reliability analysis; however, its accuracy would become worse for nonlinear problems. This paper proposes the accuracy analysis method of the first-order reliability method, which considers the worst cases when using the first-order reliability method and gives the possible value range of the probability of safety. The accuracy analysis method can evaluate the reliability level of the first-order reliability method when the failure surfaces are nonlinear. The calculation formula for the possible value range of the probability of safety is proposed, and its trend as the dimensions and reliability rise is also discussed in this paper. A numerical example and a honeycomb crashworthiness design are presented to validate the accuracy of the first-order reliability method, and the results show that they are located within the possible value range proposed in this paper.

Sensitivity of Vessel Responses to Environmental Contours of Extreme Sea States

2015 ◽  
Author(s):  
Curtis Armstrong ◽  
Christopher Chin ◽  
Irene Penesis ◽  
Yuriy Drobyshevski
Keyword(s):  
Case Studies ◽  
Return Period ◽  
Significant Wave Height ◽  
Peak Period ◽  
First Order Reliability Method ◽  
First Order ◽  
Long Wave ◽  
Contour Lines ◽  
Reliability Method ◽  
Extreme Responses

A comparative study of two methods for the generation of the environmental contours is presented investigating the sensitivity of the predicted extreme vessel responses to the type of the contour lines. Two approaches for the generation of environmental contours of the significant wave height and peak period are compared: the Inverse First Order Reliability Method (IFORM) and Constant Probability Density (CPD) approach. Case studies include several global responses of a ship-shaped weather-vaning vessel and a semisubmersible platform. The case studies reveal that the differences between the IFORM and CPD contours are more pronounced in the range of long wave periods. Vessel responses which are less sensitive to long wave periods exhibit less difference (less than 1.0%) in their maximum values between the two types of contours. In contrast, responses which are sensitive to long wave periods show significantly larger differences of up to 7.0%. Uncertainties also exist in the predicted extreme responses where the environmental contour and the response isoline behave tangentially. Differences between the extreme responses produced by the two contours generally decrease with an increase in return period; however exceptions exist due to the tangential behaviour. It is advised that these sensitivities should be taken into consideration when the environmental contours are used in the design.

scholarly journals Safety parameters calibration in the structural design of sewer liners

2018 ◽  
Vol 45 ◽  
pp. 00096
Author(s):  
Arkadiusz Szot
Keyword(s):  
Analytical Solutions ◽  
Structural Design ◽  
Safety Index ◽  
Safety Factors ◽  
Load Bearing Capacity ◽  
First Order Reliability Method ◽  
First Order ◽  
Reliability Method ◽  
Safety Parameters ◽  
Global Safety Factor

The article concerns aspects of safety in the process of designing continuous polymer liners used to strengthen and seal sewers and drains. The issues of safety coefficients, the variability of basic loadbearing parameters of liners and the problem of sensitivity of analytical solutions describing load-bearing capacity are discussed. The currently used magnitude of safety factors has been verified. The results of an examination on the safety index of liners for strengthening sewers has been presented in the paper. The necessity for the verification of current concepts of liner safety normalisation was herein addressed. A postulation to abandon the analogy of liners for newly constructed pipes was formulated. Calculations using the Hasofer-Lind safety index (First Order Reliability Method) were performed in some cases. A verification and evaluation of the global safety factor for sewer liners were herein carried out.

Reliability analysis of corroded pipelines: Novel adaptive conjugate first order reliability method

2019 ◽  
Vol 62 ◽  
pp. 103986 ◽  
Author(s):  
Behrooz Keshtegar ◽  
Mohamed El Amine Ben Seghier ◽  
Shun-Peng Zhu ◽  
Rouzbeh Abbassi ◽  
Nguyen-Thoi Trung
Keyword(s):  
Reliability Analysis ◽  
First Order Reliability Method ◽  
First Order ◽  
Reliability Method
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