[雙語翻譯]外文翻譯--克服塑性變形的壓力容器設(shè)計(jì)方法展望（英文）

1、Philippe Rohart1CETIM—Centre Technique des Industries M? ecaniques, 52, avenue Felix Louat—BP 80067, Senlis Cedex F 60304, France; Polymers and Composites Technology and Mechanical Engineering Department, ? Ecole des Min

2、es de Douai, 941 rue Charles Bourseul—BP 10038, Douai Cedex F59508, France; Universit? e des Sciences et Technologies Lille1, Cit? e Scientifique, Villeneuve d’Ascq Cedex 59655, France e-mail: philippe.rohart@cetim.frSt?

3、 ephane Panier Polymers and Composites Technology and Mechanical Engineering Department, ? Ecole des Mines de Douai, 941 rue Charles Bourseul—BP 10038, Douai Cedex F59508, France; Universit? e des Sciences et Technologie

4、s Lille1, Cit? e Scientifique, Villeneuve d’Ascq Cedex 59655, FranceYves Simonet CETIM—Centre Technique des Industries M? ecaniques, 52, avenue Felix Louat—BP 80067, Senlis Cedex F 60304, FranceSa€ ?d Hariri Polymers and

5、 Composites Technology and Mechanical Engineering Department, ? Ecole des Mines de Douai, 941 rue Charles Bourseul—BP 10038, Douai Cedex F59508, France; Universit? e des Sciences et Technologies Lille1, Cit? e Scientifiq

6、ue, Villeneuve d’Ascq Cedex 59655, FranceMansour Afzali CETIM—Centre Technique des Industries M? ecaniques, 52, avenue Felix Louat—BP 80067, Senlis Cedex F 60304, FranceA Review of State-of-the-Art Methods for Pressure V

7、essels Design Against Progressive DeformationProgressive plastic deformation is one of the damage mechanisms which can occur in pressure vessels subjected to cyclic loading. For design applications, the main rule pro- po

8、sed by codes against this failure mode is the so-called 3f (or 3Sm) criterion. During the last decade, studies have shown that this condition can be unreliable, and its applica- tion should be restricted. In parallel, th

9、eoretical developments enabled shakedown analy- ses to be considered in design methodology, and to be incorporated in codes and standards (EN13445, CODAP) from the early 2000s. This paper gives a review of inno- vative m

10、ethods based on shakedown theory, which can be used in the determination of elastic shakedown limits, ratchet limits, or cyclic steady state. These approaches are based on different concepts, such as elastic compensation

11、 linear matching method (LMM), Gokhfeld theory (uniform modified yield, load dependent yield modification (LDYM)), or the research of stabilized cycle direct cyclic analysis (DCA). Each method is presented and applied on

12、 a Benchmark example in ABAQUS, and results are compared. A final assessment focuses on computation time, and underlines the benefits that could be expected for industrial applications. [DOI: 10.1115/1.4029095]Introducti

13、onDesigning a pressure vessel consists in producing a structure whose characteristics (shape, material, thickness, etc.) will enable it to sustain a given service loading safely. The objective is to avoid the occurrence

14、of a failure mode, such as gross plastic deformation or buckling [1]. In the case of cyclic loadings, four kinds of behavior can be observed [2], illustrated in Fig. 1:? wholly elastic behavior ? shakedown, where the beh

15、avior becomes fully elastic after a limited number of cycles? reverse plasticity, where the elastic–plastic behavior becomes stabilized after a limited number of cycles, and the total de- formation over a cycle tends to

16、zero ? ratchetting, where the structure also shows an elastic–plastic behavior, but the total deformation over a cycle never tends to zeroThis last behavior, also called progressive deformation, is a fail- ure mode which

17、 could lead to the collapse of a pressure vessel. For design-by-analysis, a structure is checked through a global mechanical analysis, usually performed by a finite element code, and various methods and criteria have bee

18、n proposed.Design MethodologiesSelected design methodologies are discussed and compared in this paper. These methods are either standardized (detailed in codes for pressure vessels design), or applied according to1Corres

19、ponding author. Contributed by the Pressure Vessel and Piping Division of ASME for publication in the JOURNAL OF PRESSURE VESSEL TECHNOLOGY. Manuscript received September 17, 2013; final manuscript received November 4, 2

20、014; published online February 24, 2015. Assoc. Editor: Allen C. Smith.Journal of Pressure Vessel Technology OCTOBER 2015, Vol. 137 / 051202-1 Copyright V C 2015 by ASMEDownloaded From: http://asmedigitalcollection.asme.

21、org/ on 03/03/2016 Terms of Use: http://www.asme.org/about-asme/terms-of-useðrijÞm ¼ 1hðþh 2?h 2 rij ? dx3 (3)? ðrijÞb represents a linear bending component, whose bending moment is equ

22、al to the bending moment generated by the real stress field, and is defined asðrijÞb ¼ 12x3 h3ðþh 2?h 2 rij ? x3 ? dx3 (4)As the analysis is performed in the context of linear elasticity, the str

23、ess results require classification in order to assess integrity. The stress categories are:? Primary stress P, corresponding to the part of stress generated by the load imposed on a structure. Its value can be statically

24、 determined, participates to the equilibrium of mechanical loads, and cannot be relaxed by plastic deformation. There are two subtypes: ? primary membrane stress Pm, related to the average value of the primary stress in

25、the thickness of the wall ? primary bending stress Pb, whose variation is linear in the thickness of the wall, and responsible for the moment of primary stress ? Secondary stress Q, corresponding to the part of stress ge

26、ner- ated by the displacement imposed on a structure. It results from compatibility of deformation, and is limited by the plas- tic deformation it causes. This category also has a membrane (Qm) et bending (Qb) component.

27、 ? Local primary membrane stress PL, defined as the sum of pri- mary membrane stress and secondary membrane stress from mechanical origin ? Peak stress, caused by discontinuities of geometry or load- ings, whose effect i

28、s limited in terms of wall deformation, but critical on fatigue considerationsDesigning a pressure vessel by ESA consists of the following 3 steps:? Analysis of stress effects, depending on parameters such as the part of

29、 the vessel, the nature of the solicitation (thermal, mechanical, …), the type of stress, etc. ? Classification of stresses ? A comparison between stress levels obtained in each category and criteriaThe ESA method protec

30、ts against progressive deformation by imposing the following stress limitation:D P þ Q ð Þ ð ÞTresca< 3Sm (5)Sm depends on material properties: it is usually defined as 2=3 of the yield stress

31、. This code limit is generally conservative, as it is based on a perceptive understanding of elastic shakedown. This criterion is implemented in most of pressure vessels codes, but some recent studies have shown the meth

32、od unreliable [5]. They proved it does not constitute a reliable check against ratchet in some cases. However, it does not cause conception problems from a practical point of view, since the criterion for gross plastic d

33、eformation (another critical failure mode) turns out to be restrictive and conservative enough. ESA method was applied in ABAQUS, using the static procedure with an elastic material, and the post processing tool “stress

34、linearization” was employed to manually check stress levels.Elastic Plastic Analyses. Since 2002, European standard EN 13445-3 has proposed, in its Annex B, new methods to check the strength of a pressure vessel toward p

35、rogressive plastic deforma- tion [4].Based on first order theory, it assumes an elastic perfectly plastic behavior of the material. The analysis uses the von Mises criterion with associated flow rule. Nonoccurrence of ra

36、tchet effect can be checked with several application rules.Application Rule 1. Ratchetting can be checked by technical ad- aptation. It consists in applying on a structure the number of cycles for the considered load cas

37、e, and to verify that the maximum abso- lute value of the principal structural strains is lower than 5%.Application Rule 2. Ratchetting can then be checked by a shakedown verification. Based on Melan’s theorem, it consis

38、ts in proving that a model with stress and strain concentrations reaches a linear elastic behavior under the action cycles considered [6].Application Rule 3. Ratchetting can also be checked by techni- cal shakedown. It c

39、onsists in the following double verification:? Convergence to a linear elastic behavior under the action cycles considered, for an equivalent stress concentration free model. ? For a model with local stress and strain co

40、ncentrations, exis- tence of a time invariant self-equilibrating stress field. The sum of this stress field and the cyclically varying stress field determined with a linear elastic constitutive law for the cyclic action

41、considered must be compatible with the relevant yield condition, continuously in a core of the structure which encompasses at least 80% of every wall thickness.The objective is then the verification of one of these appli

42、cation rules by the following elastic–plastic methods.Elastic Plastic MethodsIncremental Method (INC). Incremental finite element calcu- lation consists in simulating the response of a structure to a num- ber of cycles o

43、f loading. It uses an actual elastic–plastic behavior for the material. Such a method can be used for each application rule defined pre- viously. It can, however, be limited for practical reasons, such as computation tim

44、e (due to the simulation of each cycle of loading), or accuracy (plastic strain increment eventually in the same range as numerical errors). INC method was applied in ABAQUS, using the static step procedure with an elast

45、ic–plastic material.LDYM. Yield surface modification methods are based on studies from Koiter, who gave rise to the fact that limit analysis theorems are special cases of more general shakedown and ratchet theorems [7].

46、Further works led to the definition of fictitious yield surface from Gockfeld. According to this theory, cyclic loadings effect is considered as a reduction of the capacity of a structure to sustain a constant loading [8

47、]. Shakedown and ratchet problems are finally processed as the limit analysis of a model with modified nonhomogeneous yield properties. The yield modification is defined as follows. From the initial yield stress, associa

48、ted with the von Mises criterion, comes an ini- tial yield surface with elliptic shape. The segment OK ½ ? is related to the cyclic stress vector. Adjusting the initial yield surface from a quantity depending on a v

49、ector O1K1 equal to the vector OK brings the modified yield surface. Its anisotropy highlights the dependence of the modified yield stress on both constant and cyclic loadings (Fig. 3). Implementing an accurate fictitiou

50、s yield surface would neces- sitate huge modifications in materials modeling. A simplified approach, known as LDYM method [9], has been developed to take into account anisotropy effects. It can be applied to structures s

51、ustaining a constant loading and a cyclic loading with two extrema. This procedure is not available in ABAQUS: an algorithm was then implemented in the software via subroutines UMAT and URDFIL, and provides a ratchet lim

52、it. The global methodology is described on Fig. 4.Journal of Pressure Vessel Technology OCTOBER 2015, Vol. 137 / 051202-3Downloaded From: http://asmedigitalcollection.asme.org/ on 03/03/2016 Terms of Use: http://www.asme