reliability optimization analysis based on structure of probabilistic model

1、<p>　　Reliability Optimization Analysis based on Structure of Probabilistic Model</p><p>　?。⊿cience College and Institute of Intelligent Vision and Image Information， China Three Gorges University， Yich

2、ang， Hubei， 443002， P.R. China） </p><p>　　Abstract. The implementation of a project contains a lot of uncertainty， by their nature， random uncertainty， uncertainty and human factors （such as people’s limitat

3、ions of understanding things and design methods， the use of analog approximate calculation results） due to the uncertainty of the future to better improve the structural reliability， this paper， the probability model rev

4、iewed structural reliability. </p><p>　　Key words： structural reliability； probability model； optimization </p><p>　　Introductions </p><p>　　The reliability is the nature of the pro

5、duct during use without failure. Broadly speaking， the "reliability" refers to the satisfaction of the users of the products or businesses trust. This satisfaction level is from a subjective judgment， in order

6、to make specific and quantitative judgment on product reliability， product reliability can be defined as within a predetermined time in a predetermined condition and， components （products）， equipment or system stability

7、complete function of the exten</p><p>　　1. Reliability factor </p><p>　　Reliability factor contains the durability of reliability， maintainability， and reliability of the design of the three ele

8、ments. A durability product without failure or long service life is durability. Serviceable product failure can quickly and easily through the maintenance or repair troubleshooting， is serviceable. Product maintainabilit

9、y great relationship with the structure of the product design reliability. Design reliability is key to determining product quality， due to the complexity of </p><p>　　Sufficient durability of the structure

10、in a predetermined working environment within a predetermined time period， the deterioration of the material properties will not cause the structure unacceptable failure probability. From engineering conceptually， suffic

11、ient durability means in the normal maintenance of the structure can under the conditions of normal use to the specified design life span. Overall stability refers to occurs when and after the accidental events， building

12、 structure only local</p><p>　　4. Failure model of the structural system </p><p>　　The failures of the structural system model are classified as follows： the structure of the way （statically det

13、erminate and statically indeterminate）， Component Failure nature （brittle， ductile）， the series model， parallel model， and string - parallel model. </p><p>　　4.1 Series model </p><p>　　If the st

14、ructure of any one component failure， the entire structure failure， failure analysis of the type of structural system to the series model made from brittle component statically indeterminate structure ～ series model. <

15、;/p><p>　　4.2 Parallel model </p><p>　　Member in one or more than one component failure， the remaining member or failure of ductile component， able to maintain the overall structure of the function

16、， all statically indeterminate structure failure analysis to parallel model. </p><p>　　Figure1 Parallel model </p><p>　　4.3 Series - parallel model </p><p>　　The statically indeterm

17、inate ductility member ultimate failure state of the structure is not limited to a structure， such structural system to series - parallel model. </p><p>　　Figure2 Series - parallel model </p><p>

18、;　　5. Optimization of reliability optimization </p><p>　　5.1 The reliability index </p><p>　　The reliability of the design is multiple objectives and multiple uncertainties. The objectives inclu

19、de safety， serviceability， durability and economy indicators. Without uncertainties include probabilistic uncertainty analysis probabilistic model of uncertainty， the uncertainty of the physical and mechanical model， the

20、 cross-section resistance of the basic assumptions of the formula and calculation model inaccuracies and human neglect and material properties， geometric parameters error. In engi</p><p>　　with the continuou

21、s advancement of the scientific and technological level the engineering structural complexity of the system in increasing the uncertainty of the performance along with more and more prominent. Therefore， people must carr

22、y out the analysis and decision-making under uncertainty premise. Traditional probabilistic reliability methods based on probability theory works dealing with uncertainty in the most commonly used method. With further re

23、search， people gradually discovered that i</p><p>　　5.3 The model structure of reliability optimization </p><p>　　Reliability-based structural optimization model is generally calculated by the m

24、odel and the optimization of the reliability analysis model. Reliability model involving structural response calculation （structural analysis） and structural reliability estimates， including by the response of the struct

25、ure parameters of the structural analysis model calculations to estimate the limit state function and the gradient of the basic parameters. Reliability estimates involving random parameters describe t</p><p>

26、;　　5.4 Reliability optimization algorithm to optimize the </p><p>　　Optimization algorithm， based on the sequential quadratic programming algorithm is generally considered to be the most effective and feasib

27、le method. Indirect method means to break the problem into several sub-structure （or subsystem）. Each subsystem has its own objective function and constraints. The various subsystems of the system from the low level cont

28、rol action by the system is controlled at a high level， such methods involve the flow of information between the sub-structure and problems o</p><p>　　6. The advantages of probabilistic model </p><

29、;p>　　6.1 The definition of probability models </p><p>　　Giving user a query string， equals the presence of the string that contains the collection of all related documents. We see this collection as a des

30、irable outcome document set ideal result set is given； we can easily get the result document. So we can query processing as the treatment of the property of the desired result set of documents. The problem is that we do

31、not know exactly what these attributes； we know there is an index expressed in terms of these attributes. Because these attributes a</p><p>　　6.2 Influencing factors of Probabilistic model </p><p&

32、gt;　　Changes in the real world are being affected by a number of factors， including deterministic and random. From the background， purpose and means of modeling， the main factor is to determine the random factors can be

33、ignored， or simply random factors can appear to the average effect， you will be able to establish a deterministic model. If random factors study must be taken into account， it should be the establishment of the stochasti

34、c model. </p><p>　　6.3 The advantages of probabilistic model </p><p>　　The probabilistic model has the advantage that the document can be a descending in accordance with their associated probabi

35、lities to calculate the Rank. His disadvantage： the need to guess at the beginning of the document is divided into two sets of relevant and irrelevant， in fact， this model does not consider the frequency of the index ter

36、m in the document （all weights are binary）， while the index terms are independent of each other. 　　7. Summaries </p><p>　　The probability model is based on a given user's query string and documents in t

37、he collection probability model to estimate the user's query string probability associated with the document. The probability model assumes that this probability is only determined by the query string and document. F

38、urther， the model assumes there is a collection of all the documents， that is， relative to the document subset of the result of the query string， this ideal collection represented by R， the documents in t</p><

39、p>　　Acknowledgements </p><p>　　Fund support： NSFC Grant 60972162 </p><p>　　References </p><p>　　1.Chen jianqiao. Introduction to Mechanics of Composite Materials[M]. Science Pres

40、s， 2006 </p><p>　　2.An weiguang， Chai yinlin， Chen weidong. Random structural system reliability analysis and optimization design[M]. Harbin Engineering University Press，2005 </p><p>　　3.Guo shu

41、xiang， lv zhenzhou， Feng yuansheng. The non-probabilistic reliability model based on interval analysis structure [J]. Chinese Journal of Computational Mechanics. 2001（01） </p><p>　　4.Guo shuxiang， lv zhenzho