Reliability-based design of mechanically connected built-up wood columns

1991 ◽  
Vol 18 (2) ◽  
pp. 171-181 ◽  
Author(s):  
S. K. Malhotra ◽  
A. P. Sukumar
Keyword(s):  
Data Base ◽  
Reliability Analysis ◽  
Rational Model ◽  
Limit States ◽  
Wood Structures ◽  
Factors Affecting ◽  
Analysis And Design ◽  
Additional Information ◽  
Reliability Based Design ◽  
First Order Second Moment

Built-up wood structural components and systems have been in use in the building industry for decades. Though easy to construct, they are rather complex to analyze because of numerous factors affecting their strength and behaviour. This paper explains the development of a reliability-based design formulation in limit states for built-up columns, using a rational mathematical model for the analysis and design. Also, a brief discussion is given on a set of simplified design rules for layered columns which have been incorporated into the Canadian Standards Association Standard CAN3-086.1-M89 "Code for engineering design in wood (limit states design)." The rational model as well as the simplified rules are subjected to reliability analysis.The Canadian specifications for the design of wood structures in limit states format have been available since December 1984. These specifications are essentially a soft conversion of the previous working stress design code. The 1989 edition of the code is mostly based on the principles of reliability-based design. Some portions of the code are still not fully based on reliability approach, as additional information is needed for the establishment of a reliable data base upon which the "uncertainty factors" could be redefined in a more rational and logical manner. This paper provides that type of information and the details of reliability analysis as applied to mechanically connected built-up timber columns. The reliability analyses are performed based on first-order second-moment methods, using a data base of column strengths. The data base consists of experimental as well as simulated results. Two reliability analysis programs, BUCREL (built-up column reliability analysis) and POINT (reliability analysis using design point algorithm), are developed. Design recommendations are derived in a reliability-based design format. Key words: buckling, columns, design specifications, efficiency, joints, layered columns, rational model, reliability, resistance factor, slip, spaced columns, timber, wood.

Reliability Evaluation of AASHTO Design Equations for Drilled Shafts

1997 ◽  
Vol 1582 (1) ◽  
pp. 60-67
Author(s):  
William M. Isenhower ◽  
James H. Long
Keyword(s):  
Data Base ◽  
Reliability Evaluation ◽  
Drilled Shafts ◽  
Drilled Shaft ◽  
Factors Affecting ◽  
First Order ◽  
Axial Capacity ◽  
Moment Methods ◽  
First Order Second Moment ◽  
Load Tests

A reliability evaluation of the AASHTO design equations for drilled shafts is described. The evaluation computed the variance of a data base containing load tests to failure on 30 straight-sided drilled shafts using first-order, second-moment methods applied to the AASHTO design equations. The computed variance was compared with the measured variance of the data base. The measured variance was found to exceed the computed variance for approximately 75 percent of the load tests. This is believed to result from important factors affecting the axial capacity of the drilled shaft not being included in the AASHTO design equations. It is speculated that the missing factors are related to common variations in construction practices for drilled shafts.

Reliability Analysis and Design Suggestion of Concrete Structure Bonded Rebars with Inorganic Material

2010 ◽  
Vol 163-167 ◽  
pp. 3586-3590
Author(s):  
Yu Guo Liang ◽  
Tian Bao Gao ◽  
Yu Deng
Keyword(s):  
Reliability Analysis ◽  
Inorganic Material ◽  
Limit State ◽  
State Equation ◽  
Analysis And Design ◽  
Design Suggestion ◽  
Testing Data ◽  
Calculation Results ◽  
First Order Second Moment ◽  
Second Moment Method

Based on the established limit state equation and connected with a large amount of statistic analysis of testing data, central point law in first order second moment method (FOSM) is adopted to the reliability analysis of bonded rebars with inorganic material. The adhesive anchorage design suggestion of bonded rebars with inorganic material is proposed. By means of comparing the calculation results to experimental results, it can be concluded that the calculation methods of anchorage length can be used to the calculation of designing concrete bonded rebars.

scholarly journals RELIABILITY ANALYSIS OF A TWO SPAN FLOOR DESIGNED ACCORDING TO EUROCODE 5

2016 ◽  
Vol 36 (1) ◽  
pp. 18-25
Author(s):  
EN Ogork ◽  
AK Nakore
Keyword(s):  
Reliability Analysis ◽  
Structural Reliability ◽  
Load Ratio ◽  
Structural Safety ◽  
Live Load ◽  
Structural Elements ◽  
Limit States ◽  
Analysis And Design ◽  
Modes Of Failure ◽  
Reliability Method

This paper presents the structural reliability assessment of a two span timber floor of strength class D40 designed in accordance with Eurocode 5 (2004).  The Structural analysis and design of the timber floor system was carried out using deterministic approach, considering both ultimate and serviceability limit states. Reliability analysis of the floor structural elements to ascertain its level of safety was carried out using first order reliability method (FORM) for the four modes of failure of bending shear, bearing and deflection. The reliability analysis involved investigation of the effects of variation of the applied dead to live load ratio and the cross sectional parameters of the floor. The results revealed that the deterministic design is satisfactory as limiting stresses and deflection were not exceeded. The primary floor joists had safety indices in shear and bending of 1.2 to 2.8 with decrease in dead to live load ratio and were below the recommended safety index of 3.8 specified in joint committee on structural safety (JCSS). The timber floor structural elements are more reliable in bearing, shear and deflection and critical in bending mode of failure. The section depth and span of floor elements are more sensitive in bending and deflection modes than shear and bearing modes. http://dx.doi.org/10.4314/njt.v36i1.3

Reliability-based design of wood structures: background to CSA-086.1-M89

1993 ◽  
Vol 20 (3) ◽  
pp. 349-357 ◽  
Author(s):  
Ricardo O. Foschi ◽  
Bryan Folz ◽  
Felix Yao
Keyword(s):  
Calibration Procedure ◽  
Code Design ◽  
Limit States ◽  
Wood Structures ◽  
Design Procedures ◽  
Reliability Based Design ◽  
Working Stress ◽  
Adjustment Factors ◽  
Duration Of Load ◽  
The Impact

The limit states design version of the 1989 Canadian code for engineering design in wood (CSA-086.1-M89) is, for the most part, reliability-based. This paper discusses the methodology employed in the calibration procedure and the reliability levels adopted. Particular emphasis is given to the results obtained for duration of load and system (load sharing) strength adjustment factors, to serviceability limit states, and to the design of columns. Final comments address the impact of the new code in comparison to the traditional working stress design procedures. Key words: code, design, reliability, timber construction, wood.

Reliability Analysis and Design of Epicyclic Gear Trains

1979 ◽  
Vol 101 (4) ◽  
pp. 625-632 ◽  
Author(s):  
S. S. Rao
Keyword(s):  
Reliability Analysis ◽  
Structural Reliability ◽  
Design Criterion ◽  
Gear Train ◽  
Design Parameters ◽  
Analysis And Design ◽  
Input Shaft ◽  
Reliability Based Design ◽  
Epicyclic Gear ◽  
Gear Trains

The concepts of system reliability are applied for the structural reliability analysis and design of epicyclic gear trains. The reliability analysis is based on the representation of an epicyclic gear train as a series-parallel network. The power transmitted, the speed of the input shaft, the center distance between the gear pairs and the permissible stresses are assumed to be random variables following normal distribution. The layout of the gears and the speed ratios are assumed to be known. The face widths of the gears are taken as random design parameters. The design criterion is that the reliability of the gear train either in bending or surface wear failure mode at any of the output speeds must be equal to a specified value. The design of an epicyclic transmission system which gives four forward speeds and one reverse speed is considered for illustration. The results of the reliability-based design of the gear train are compared with those of the conventional deterministic design.

STRUCTURAL RELIABILITY ANALYSIS BASED ON P-BOXES

2020 ◽  
Vol 92 (6) ◽  
pp. 51-58
Author(s):  
S.A. SOLOVYEV ◽  
Keyword(s):  
Probability Distribution ◽  
Reliability Analysis ◽  
Structural Reliability ◽  
Epistemic Uncertainty ◽  
Random Variable ◽  
Strength Criterion ◽  
Structural Elements ◽  
Structural Element ◽  
Limit States ◽  
Distribution Shape

The article describes a method for reliability (probability of non-failure) analysis of structural elements based on p-boxes. An algorithm for constructing two p-blocks is shown. First p-box is used in the absence of information about the probability distribution shape of a random variable. Second p-box is used for a certain probability distribution function but with inaccurate (interval) function parameters. The algorithm for reliability analysis is presented on a numerical example of the reliability analysis for a flexural wooden beam by wood strength criterion. The result of the reliability analysis is an interval of the non-failure probability boundaries. Recommendations are given for narrowing the reliability boundaries which can reduce epistemic uncertainty. On the basis of the proposed approach, particular methods for reliability analysis for any structural elements can be developed. Design equations are given for a comprehensive assessment of the structural element reliability as a system taking into account all the criteria of limit states.

scholarly journals Comparison of reliability evaluation methods between China and Canada standards for wood structures featuring duration of load

2020 ◽  
Vol 66 (1) ◽  
Author(s):  
Qiongyao Wu ◽  
Shuang Niu ◽  
Enchun Zhu
Keyword(s):  
Reliability Analysis ◽  
Analysis Method ◽  
Safety Level ◽  
Wood Structures ◽  
Load Effect ◽  
Key Factor ◽  
Live Loads ◽  
High Level ◽  
Partial Factor ◽  
Duration Of Load

Abstract Duration of load (DOL) is a key factor in design of wood structures, which makes the reliability analysis of wood structures more complicated. The importance of DOL is widely recognized, yet the methods and models through which it is incorporated into design codes vary substantially by country/region. Few investigations of the effect of different model assumptions of DOL and other random variables on the results of reliability analysis of wood structures can be found. In this paper, comparisons are made on the reliability analysis methods that underlie the China and the Canada standards for design of wood structures. Main characteristics of these two methods, especially the way how DOL is treated are investigated. Reliability analysis was carried out with the two methods employing the same set of material properties and load parameters. The resulted relationships between reliability index β and resistance partial factor γR* (the β–γR* curves) for four load combinations are compared to study the safety level indicated by the two methods. The comparison shows that the damage accumulation model (Foschi–Yao model) in the Canada analysis method is highly dependent on the type and duration of load, resulting in more conservative design than the China analysis method in loading cases dominated by dead load, but less conservative design in cases of high level of live loads. The characteristics of the load effect term of the performance function are also found to make considerable difference in reliability levels between the two methods. This study aims to provide references for researchers and standard developers in the field of wood structures.

Functional Reliability Analysis of Post-Earthquake Water Supply System

2013 ◽  
Vol 438-439 ◽  
pp. 1551-1554
Author(s):  
Shuang Hua He
Keyword(s):  
Water Supply ◽  
Reliability Analysis ◽  
Distribution System ◽  
Water Distribution ◽  
Supply System ◽  
Water Supply System ◽  
Control Analysis ◽  
First Order Second Moment ◽  
Functional Reliability ◽  
Dependent Demand

Conventional demand-driven models of water supply system are formulated under the assumption that nodal demands are statistic constants, which is not suitable for the cases where nodal pressure is not sufficient for supplying the required demand. An efficient approach for pressure-dependent demand analysis was developed to simulate the hydraulic states of the network for low pressure scenarios, and the mean-first-order-second-moment method was introduced to do the functional reliability analysis of post-earthquake water supply system, which can be applied to further study for seismic performance control analysis of water distribution system.

Process Piping: The Complete Guide to ASME B31.3, Fourth Edition

2021 ◽  
Author(s):  
Charles Becht, IV
Keyword(s):  
Pipe Wall ◽  
Background Information ◽  
Fourth Edition ◽  
Expansion Joints ◽  
Analysis And Design ◽  
Additional Information ◽  
Flexibility Analysis ◽  
Process Piping ◽  
Expert Commentary ◽  
Welding Processes

Fully updated for the 2020 Edition of the ASME B31.3 Code, this fourth edition provides background information, historical perspective, and expert commentary on the ASME B31.3 Code requirements for process piping design and construction. It provides the most complete coverage of the Code that is available today and is packed with additional information useful to those responsible for the design and mechanical integrity of process piping. The author and the primary contributor to the fourth edition, Don Frikken are a long-serving members, and Prior Chairmen, of the ASME B31.3, Process Piping Code committee. Dr. Becht explains the principal intentions of the Code, covering the content of each of the Code's chapters. Book inserts cover special topics such as calculation of refractory lined pipe wall temperature, spring design, design for vibration, welding processes, bonding processes and expansion joint pressure thrust. Appendices in the book include useful information for pressure design and flexibility analysis as well as guidelines for computer flexibility analysis and design of piping systems with expansion joints. From the new designer wanting to known how to size a pipe wall thickness or design a spring to the expert piping engineer wanting to understand some nuance or intent of the code, everyone whose career involves process piping will find this to be a valuable reference.

scholarly journals Evaluation of the Mean Platelet Volume and Red Cell Distribution Width in FMF: Are They Related to Subclinical Inflammation or Not?

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Gozde Yildirim Cetin ◽  
Ozlem Gul ◽  
Fatma Kesici-Metin ◽  
İrem Gokalp ◽  
Mehmet Sayarlıoglu
Keyword(s):  
Negative Correlation ◽  
Treatment Decision ◽  
Control Group ◽  
Subclinical Inflammation ◽  
Distribution Width ◽  
Factors Affecting ◽  
Additional Information ◽  
Large Numbers ◽  
Healthy Control ◽  
Group A

In this paper we want to demonstrate whether higher than normal levels of RDW, and lower than normal levels of MPV can be used as indicators of subclinical inflammation and tools for treatment decision in FMF or not. The participants in this study included 89 patients with FMF during attack-free periods and 30 healthy controls. The RDW and platelet counts were significantly higher, while the MPV was significantly lower in the patients with FMF group than healthy control group (P<0.001;P=0.005;P<0.001, resp.). In the attack-free FMF group, a negative correlation was found between the MPV and RDW values (P<0.001,r=-0.40). The positive correlation was found between the RDW and ESR (r=0.23,P=0.028). And the negative correlation was found between the MPV and CRP (r=-0.216,P=0.042). Consequently, our results suggest that low MPV and high RDW levels may provide additional information about subclinical inflammation in FMF patients. But other strong predisposing factors affecting subclinical inflammation in FMF should be considered. Further studies with large numbers of patients are needed. Treatment of FMF should include not only prevention of acute attacks but also decreasing of the subclinical inflammation.

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