scholarly journals A straightforward moment method to estimate the load and resistance factors

2019 ◽  
Vol 652 ◽  
pp. 012042
Author(s):  
X Y Zhang
Keyword(s):  
Moment Method ◽  
Resistance Factors ◽  
Load And Resistance Factors

scholarly journals Improved Calculation of Load and Resistance Factors Based on Third-Moment Method

2021 ◽  
Vol 11 (19) ◽  
pp. 9107
Author(s):  
Jiao Wang ◽  
Xinying Ye ◽  
Weiji Zheng ◽  
Peng Liu
Keyword(s):  
Moment Method ◽  
Random Variables ◽  
Reliability Design ◽  
Resistance Factors ◽  
Iterative Computation ◽  
Load And Resistance Factors ◽  
Applicable Range ◽  
Factor Design ◽  
Load And Resistance Factor ◽  
Third Moment

Load and resistance factor design (LRFD) is widely used in building codes for reliability design. In the calculation of load and resistance factors, the third-moment method (3M) has been proposed to overcome the shortcomings (e.g., inevitable iterative computation, requirement of probability density functions (PDFs) of random variables) of other methods. With the existing 3M method, the iterative is simplified to one computation, and the PDFs of random variables are not required. In this paper, the computation of load and resistance factors is further simplified to no iterations. Furthermore, the accuracy of the proposed method is proved to be higher than the existing 3M methods. Additionally, with the proposed method, the limitations regarding applicable range in the existing 3M methods are avoided. With several examples, the comparison of the existing 3M method, the ASCE method, the Mori method, and the proposed method is given. The results show that the proposed method is accurate, simple, safe, and saves material.

Comparative Review of the Established UHB Assessment Methods for Offshore Pipelines

2015 ◽  
Author(s):  
Sajith Kumar ◽  
Daniel Smith ◽  
Hooman Jafari
Keyword(s):  
Survey Data ◽  
Structural Reliability ◽  
Load Resistance ◽  
Design Parameters ◽  
Operational Parameters ◽  
Resistance Factors ◽  
Upheaval Buckling ◽  
Variation Of Parameters ◽  
Comparative Review ◽  
Load And Resistance Factors

Out of straightness upheaval buckling (OOS UHB) assessment considers the pipeline design and operational parameters, post-lay survey data and the properties of back-fill and rock in order to determine load and resistance factors that are applied. The factors allow for the natural variation of all parameters and are ultimately used to determine the download requirements along the route of a pipeline that is susceptible to UHB. Two methods are most commonly used in OOS UHB assessments. The structural reliability analysis (SRA) method is the most established and explicitly considers the variation of parameters in a Monte-Carlo simulation, enabling load and resistance factors to be calculated with a defined reliability level. A more recently developed methodology is documented in DNV-RP-F110 and provides a unified approach to the calculation of safety factors. The approach was calibrated using structural reliability based methods, undertaken with target reliability levels that are compliant with DNV-OS-F101. This paper presents a review of two key components of OOS UHB assessments. These components are the accuracy of post-lay survey data and the load resistance factor calculation method. These components are reviewed in the context of SRA and DNV-RP-F110 based assessments for a range of pipeline sizes, and ranges of soil and operational parameters. This enables characterisation of the differences between the two methodologies for ranges of design parameters that represent the majority of in-field flowlines that are installed in the United kingdom Continental Shelf (UKCS). SRA and DNV-RP-F110 derived load and resistance factors are compared and the effect of survey data smoothing upon rock-dump requirements is also discussed.

Load and Resistance Factors for Progressive Collapse Resistance Design of Reinforced Concrete Building Structures

2011 ◽  
Vol 255-260 ◽  
pp. 338-344 ◽  
Author(s):  
Ying Wang ◽  
Feng Lin ◽  
Xiang Lin Gu
Keyword(s):  
Reinforced Concrete ◽  
Progressive Collapse ◽  
Building Structures ◽  
Safety Factors ◽  
Ultimate State ◽  
Resistance Factors ◽  
Collapse Resistance ◽  
Load And Resistance Factors ◽  
Load Effects ◽  
Partial Safety Factors

Due to the absence of provision for the load and resistance factors in design codes in China, designers often quote the provisions which are given in criterion or guidance of other countries such as USA. However, the partial safety factors of the load are various in different criterions. Based on the reliability theory, the load and resistance factors for progressive collapse resistance design of building structures were determined in this study. Firstly the simplified format of design expression in the ultimate state was obtained according to the expression in routine structural design. Then the failure probability of a structure during design reference period was taken as the sum of the probability of all incompatible failure events in this period, and the objective reliability index of the structure could be obtained. Finally using trial-and-error procedure and JC method, reliability analysis was performed for structural members to obtain the partial safety factors of load effects and resistance and the coefficient for combination value of load effects in design expression in the ultimate state. In this paper the load and resistance factors for progressive collapse resistance design of reinforced concrete structures subjected to blast was calculated as an example, and the recommendation values were given for the application at last.

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