Reduced Partial Factors for Assessment in Uk Assessment Standards

2018 ◽  
Author(s):  
C. R. Hendy ◽  
L. S. Man ◽  
R. P. Mitchell ◽  
H. Takano
Keyword(s):  
Structural Reliability ◽  
Distribution Model ◽  
Reference Period ◽  
Minimum Level ◽  
Design Standards ◽  
Reliability Level ◽  
Assessment Standards ◽  
Input Variables ◽  
Distribution Type ◽  
The Cost

Design standards are based upon a range of input variables for resistance, action and modelling. The distribution type and parameters for each determine the partial factors appropriate to achieve a defined reliability level over a specified reference period. For assessment a reduced reliability level may be accepted due to the greater cost of providing reliability through strengthening when compared to the cost of providing it at design. This would allow the use of lower partial factors, although they are still limited by the need to provide a minimum level for human safety. Adoption of this approach for assessment would have significant benefits for an ageing UK infrastructure by reducing the need to carry out costly strengthening and retrofitting schemes whilst still ensuring appropriate structural reliability levels are maintained. This paper presents a study investigating appropriate reduced partial factors to be applied through UK assessment standards, the sensitivity of these values to input distribution model assumptions, and how they could be implemented in industry.

scholarly journals From Probabilistic to Quantile-Oriented Sensitivity Analysis: New Indices of Design Quantiles

Symmetry ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 1720 ◽  
Author(s):  
Zdeněk Kala
Keyword(s):  
Sensitivity Analysis ◽  
Structural Reliability ◽  
Building Design ◽  
Design Standards ◽  
Average Value ◽  
Sensitivity Indices ◽  
Before And After ◽  
Input Variables ◽  
Total Sensitivity

In structural reliability analysis, sensitivity analysis (SA) can be used to measure how an input variable influences the failure probability Pf of a structure. Although the reliability is usually expressed via Pf, Eurocode building design standards assess the reliability using design quantiles of resistance and load. The presented case study showed that quantile-oriented SA can provide the same sensitivity ranking as Pf-oriented SA or local SA based on Pf derivatives. The first two SAs are global, so the input variables are ranked based on total sensitivity indices subordinated to contrasts. The presented studies were performed for Pf ranging from 9.35 × 10−8 to 1–1.51 × 10−8. The use of quantile-oriented global SA can be significant in engineering tasks, especially for very small Pf. The proposed concept provided an opportunity to go much further. Left-right symmetry of contrast functions and sensitivity indices were observed. The article presents a new view of contrasts associated with quantiles as the distance between the average value of the population before and after the quantile. This distance has symmetric hyperbola asymptotes for small and large quantiles of any probability distribution. Following this idea, new quantile-oriented sensitivity indices based on measuring the distance between a quantile and the average value of the model output are formulated in this article.

Statistical Evaluation for claims and disputes in construction contracts

2017 ◽  
Vol 5 (2) ◽  
pp. 80-96
Author(s):  
Raid Saleem Abd Ali ◽  
Nooran kanaan Yassin
Keyword(s):  
Construction Projects ◽  
Statistical Evaluation ◽  
Relative Importance ◽  
Minimum Level ◽  
Construction Contracts ◽  
Long Period ◽  
Price Schedule ◽  
Questionnaire Form ◽  
The Subject ◽  
The Cost

This research aims to diagnose and identify the causes of claims and disputes between the contractor and the employer, also review the methods used to resolve disputes in construction contracts. In order to achieve the goal of the research, scientific methodology is followed to collect information and data on the subject of claims and disputes in construction projects in Iraq through personal interviews and questionnaire form. The most important results in this research are: the price schedule contract as a kind of competitive contracts is the most important and guarantee for the completion of minimum level of claims and disputes with relative importance of (84.1), compared with the (cost plus a percentage of the cost contract) as a kind of negotiating contracts is the most relative importance of (79.6), and the turnkey contract as a kind of special contracts is the most relative importance of (74.2). The  contractor and  his agents are one of the most influence sources in occurring claims and disputes in construction contracts with relative importance of (77.4) followed by the contract documents with relative importance of (74.2) and then the employer with relative importance of (73.2). In addition to the long period of litigation and the multiplicity of veto grades are most negative when contractual disputes have resolved by it, and with relative importance of (86), followed by the large number of issues and lack of efficiency and specialty of Judges with relative importance (78.4). Finally, the direct negotiation method (relative importance of 77) is one of the most friendly settlement ways favored by conflicted parties, while the resolution of disputes and claims board (relative importance of 10) occupied the last rank in the friendly settlement ways.

Optimized Mooring Line Simulation Using a Hybrid Method Time Domain Scheme

2014 ◽  
Author(s):  
Niels Hørbye Christiansen ◽  
Per Erlend Torbergsen Voie ◽  
Jan Høgsberg ◽  
Nils Sødahl
Keyword(s):  
Hybrid Method ◽  
Time Domain ◽  
Computation Time ◽  
Mooring Line ◽  
Mooring Lines ◽  
Fem Model ◽  
Input Variables ◽  
The Time Domain ◽  
The Cost ◽  
Short Time

Dynamic analyses of slender marine structures are computationally expensive. Recently it has been shown how a hybrid method which combines FEM models and artificial neural networks (ANN) can be used to reduce the computation time spend on the time domain simulations associated with fatigue analysis of mooring lines by two orders of magnitude. The present study shows how an ANN trained to perform nonlinear dynamic response simulation can be optimized using a method known as optimal brain damage (OBD) and thereby be used to rank the importance of all analysis input. Both the training and the optimization of the ANN are based on one short time domain simulation sequence generated by a FEM model of the structure. This means that it is possible to evaluate the importance of input parameters based on this single simulation only. The method is tested on a numerical model of mooring lines on a floating off-shore installation. It is shown that it is possible to estimate the cost of ignoring one or more input variables in an analysis.

An Efficient Response Surface Method Using Givens Transformation for Structural Reliability Analysis

2012 ◽  
Vol 532-533 ◽  
pp. 408-411
Author(s):  
Wei Tao Zhao ◽  
Yi Yang ◽  
Tian Jun Yu
Keyword(s):  
Response Surface ◽  
Response Surface Method ◽  
Structural Reliability ◽  
Limit State ◽  
State Function ◽  
Limit State Function ◽  
Surface Method ◽  
Mathematical Techniques ◽  
Input Variables ◽  
Improved Accuracy

The response surface method was proposed as a collection of statistical and mathematical techniques that are useful for modeling and analyzing a system which is influenced by several input variables. This method gives an explicit approximation of the implicit limit state function of the structure through a number of deterministic structural analyses. However, the position of the experimental points is very important to improve the accuracy of the evaluation of failure probability. In the paper, the experimental points are obtained by using Givens transformation in such way these experimental points nearly close to limit state function. A Numerical example is presented to demonstrate the improved accuracy and computational efficiency of the proposed method compared to the classical response surface method. As seen from the result of the example, the proposed method leads to a better approximation of the limit state function over a large region of the design space, and the number of experimental points using the proposed method is less than that of classical response surface 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.

OPTIMAL ENERGY DESIGN AND RETROFIT RECOMMENDATIONS FOR THE TURKISH BUILDING SECTOR

2021 ◽  
Vol 16 (1) ◽  
pp. 61-90
Author(s):  
Selçuk Sayin ◽  
Godfried Augenbroe
Keyword(s):  
Energy Saving ◽  
Large Scale ◽  
Optimal Strategies ◽  
Energy Performance ◽  
Optimization Approach ◽  
Investment Strategies ◽  
Single Family ◽  
Building Sector ◽  
Design Standards ◽  
The Cost

ABSTRACT This paper introduces methodologies and optimal strategies to reduce the energy consumption of the building sector with the aim to reduce global energy usage of a given .region or country. Many efforts are underway to develop investment strategies for large-scale energy retrofits and stricter energy design standards for existing and future buildings. This paper presents a study that informs these strategies in a novel way. It introduces support for the cost-optimized retrofits of existing, and design improvements of new buildings in Turkey with the aim to offer recommendations to individual building owners as well as guidance to the market. Three building types, apartment, single-family house and office are analyzed with a novel optimization approach. The energy performance of each type is simulated in five different climate regions of Turkey and four different vintages. For each vintage, the building is modelled corresponding to local Turkish regulations that applied at the time of construction. Optimum results are produced for different goals in terms of energy saving targets. The optimization results reveal that a 50% energy saving target is attainable for the retrofit and a 40% energy saving target is attainable for new design improvements for each building type in all climate regions.

Statistical Inference of LZL-Type Mass Flowmeter Life Distribution Model

2010 ◽  
Vol 458 ◽  
pp. 173-178
Author(s):  
Zhen Zhou ◽  
L.N. Zhang ◽  
Y. Qin ◽  
D.Z. Ma ◽  
B. Niu
Keyword(s):  
Least Square ◽  
Distribution Model ◽  
Maintenance Policy ◽  
Life Distribution ◽  
Mass Flowmeter ◽  
Failure Data ◽  
Distribution Type ◽  
Two Parameter ◽  
Field Failure ◽  
Type Mass

Characteristics of field failure data are analyzed in this paper. The failure data and sales record of LZL-type mass flowmeter are used to infer life distribution of this conduct. The lines can be fitted in coordinates of six distribution using least square and the residual sum of squares are compared, the minimum correspond is the best distribution type. The results show that the life distribution style of this conduct is the two parameter exponential distribution, which is the base to analyze and predict failure development, research failure mechanism and draw up maintenance policy.

scholarly journals BioPartsBuilder: a synthetic biology tool for combinatorial assembly of biological parts

2015 ◽  
Vol 32 (6) ◽  
pp. 937-939 ◽  
Author(s):  
Kun Yang ◽  
Giovanni Stracquadanio ◽  
Jingchuan Luo ◽  
Jef D. Boeke ◽  
Joel S. Bader
Keyword(s):  
Large Scale ◽  
Supplementary Information ◽  
Market Place ◽  
Design Standards ◽  
Reusable Components ◽  
Assembly Design ◽  
Amazon Web Services ◽  
Dna Elements ◽  
Combinatorial Assembly ◽  
The Cost

Abstract Summary: Combinatorial assembly of DNA elements is an efficient method for building large-scale synthetic pathways from standardized, reusable components. These methods are particularly useful because they enable assembly of multiple DNA fragments in one reaction, at the cost of requiring that each fragment satisfies design constraints. We developed BioPartsBuilder as a biologist-friendly web tool to design biological parts that are compatible with DNA combinatorial assembly methods, such as Golden Gate and related methods. It retrieves biological sequences, enforces compliance with assembly design standards and provides a fabrication plan for each fragment. Availability and implementation: BioPartsBuilder is accessible at http://public.biopartsbuilder.org and an Amazon Web Services image is available from the AWS Market Place (AMI ID: ami-508acf38). Source code is released under the MIT license, and available for download at https://github.com/baderzone/biopartsbuilder. Contact: [email protected] Supplementary information: Supplementary data are available at Bioinformatics online.

Computer-Integrated Design and Manufacturing of Packaging Machines

2005 ◽  
Author(s):  
Scott E. Buske ◽  
Tien-I Liu
Keyword(s):  
Knowledge Base ◽  
Integrated Design ◽  
Base System ◽  
Design Standards ◽  
User Input ◽  
Tool Paths ◽  
Warning Messages ◽  
Knowledge Base System ◽  
The Cost ◽  
Design And Manufacture

Automated packaging machines must be constantly redesigned to accommodate ever changing packing. There is little time to make these changes and no room for error. In this work, computer-integrated design and manufacture of a packaging machine has been conducted. A knowledge base system has been developed, which checks for errors in user input, updates all assemblies per the user input, checks for part interferences in the assembly, holds the new design to accepted design standards, and sends warning messages to the user’s computer screen in the event of a problem. The knowledge base then creates new intelligent part numbers. These part numbers provide the informational link from Engineering to Production as they contain all the new part information needed to make the parts. These part numbers are entered into a program that automatically creates the new tool paths for the CNC mill. The entered part number is automatically milled into the part to insure the correct part was entered. The cost of design and manufacture is then reduced substantially. This knowledge base also extends into sales for quoting and for new job creation which expedites the entire process.

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