焊接結(jié)構(gòu)疲勞評(píng)估教程課件

1、K.Frank在UTA所做實(shí)驗(yàn)(2004)在UTC/UMR 所做實(shí)驗(yàn)(2003)DOT資助的信號(hào)燈支架實(shí)體實(shí)驗(yàn)DOT Recently Funded Full Scale Tests Signal Mast ArmTests by K. Frank at UTA (04)Tests at UTC/UMR (03)202實(shí)體剛度測試 (Frank,2004)Full Scale Stiffener Tests (Frank,04)203實(shí)體大梁的四點(diǎn)彎曲測試（Fisher）Without Cover Plate無蓋板測試With Cover Plate帶焊接蓋板測試Fishers Tests o

2、n Full Scale Girders with and without Cover Plate204基于結(jié)構(gòu)應(yīng)力的相關(guān)性測試 (Fisher, 1971)Structural Stress Based Correlation Fishers Full Scale Tests (1971)205DOT實(shí)體測試匯總All Full Scale DOT Tests206How About Correlation with the Master S-N Curve?與主 S-N曲線的相關(guān)性如何？主S-N曲線： 標(biāo)準(zhǔn)方差 0.25Master S-N Curve: Std Deviation: 0.

3、25207焊態(tài)、UIT數(shù)據(jù)(Frank, 2003-2004)與主S-N 曲線As-Welded versus UIT Treated Data (Frank, 03-04) Plotted Against the Master S-N Curve208Test Data Analysis of Tubular K joints -UKOSRP IIK型管接頭測試數(shù)據(jù)分析UKOSRP II 209管接頭測試數(shù)據(jù)(UKOSRP II)與JIP主S-N曲線的關(guān)系主S-N曲線 (2005) Tubular Joint Test Data (UKOSRP II) and Correlation wit

4、h JIP Master S-N CurveLines:Master S-N (2005)210鋁合金MIG焊縫(Ford提供數(shù)據(jù))40Conventional Method: Nominal Stress Parameter傳統(tǒng)方法：名義應(yīng)力參數(shù)Battelle Method: Structural Stress ParameterBattelle方法：結(jié)構(gòu)應(yīng)力參數(shù)Aluminum Alloy MIG Welds (Courtesy of Ford)211鋁合金激光焊的主S-N曲線(Ford提供數(shù)據(jù))Master S-N Curve for Aluminum Alloy Laser Weld

5、s (Courtesy of Ford) 212基于斷裂力學(xué)和S-N曲線進(jìn)行疲勞壽命評(píng)估的等效性Equivalence between Fracture Mechanics and S-N Curve Based Fatigue Assessments For all the data processed, the following can be concluded 由處理得到的數(shù)據(jù)結(jié)果，可以得到如下結(jié)論： Parameters C and m (crack growth rate data) uniquely determine S- N behavior 參數(shù)C和m(裂紋生長率數(shù)據(jù))可唯

6、一確定S-N曲線 Life Prediction can be done with either (1) or (2) 由式(1)或(2)進(jìn)行壽命預(yù)測： Weld quality (i.e., af) effects 焊接質(zhì)量(af)的影響 Total life 總壽命 Remaining life prediction 剩余壽命預(yù)測213初始裂紋尺寸對(duì)壽命的影響Initial “Crack” Size Effects on Life Integral I(r, ai/t, af/t) ： Quantify weld quality effects (ai/t) on fatigue tren

7、gth 量化焊縫質(zhì)量 (ai/t)對(duì)疲勞強(qiáng)度的影響 Remaining life assessment for given ai/t and af/t FFS 對(duì)給定的ai/t 和af/t進(jìn)行剩余壽命評(píng)估-FFS Why not directly using fracture mechanics then 為什么不直接使用斷裂力學(xué)方法進(jìn)行分析 - K solutions availability for complex joint types 能否得到復(fù)雜接頭的K解 - Material data availability 能否得到材料數(shù)據(jù) Comprehensive Ss-N data ca

8、n be used here 這里所能使用的可理解的Ss-N 數(shù)據(jù)214總 結(jié)Concluding RemarksFracture mechanics applications of the structural stress method 結(jié)構(gòu)應(yīng)力法中的斷裂力學(xué) Effective engineering estimation of K in complex joints 有效估算工程中復(fù)雜接頭的K值 Unified crack growth model: two stage crack growth model 統(tǒng)一的裂紋擴(kuò)展模型：兩階段模型The structural stress ba

9、sed Master S-N curve provide a single parameter description of : 基于結(jié)構(gòu)應(yīng)力的主S-N曲線提供了單參數(shù)描述方法： Thickness(t) 厚度(t) Loading Mode(r) 載荷模式(r) Stress concentration ( ) 應(yīng)力集中( ) Validated by correlating S-N data of over 5000 fatigue tests 超過5000次測試數(shù)據(jù)驗(yàn)證S-N曲線的正確性The method also offers an effective alternative met

10、hod for remaining life or FFS assessment 該方法還對(duì)剩余壽命或FFS評(píng)估提供了一個(gè)有效的替代方法215Structural Stress Modeling Procedure and Life Prediction結(jié)構(gòu)應(yīng)力建模過程與壽命預(yù)測 Structural stress modeling and life prediction procedures dos and donts 結(jié)構(gòu)應(yīng)力建模與壽命預(yù)測須知 Failure definition 失效定義 Weld line definition 焊線定義 Weld line curvature con

11、siderations 焊線曲率因素 Weld representation considerations 焊線表示方法的考慮 Load controlled versus displacement controlled (load shielding) conditions 載荷控制與位移控制(負(fù)載屏蔽)條件Implications on fatigue testing procedures 疲勞測試程序的影響因素 Failure definition and monitoring 失效的定義與監(jiān)測 Simple specimens versus component testing 簡單樣本

12、與組件測試 Life prediction examples 壽命預(yù)測例子 SAE FD&E “WELD CHALLENGE” problem - SAE“焊接疲勞挑戰(zhàn)”中的疲勞問題 Yagis tests - Yagi測試 Analysis of ISSC full scale component tests - ISSC組件實(shí)體測試 A recent full scale ASME Div 2 vessel tests - ASME標(biāo)準(zhǔn)中壓力容器測試 MIG and welded component tests aluminum alloys - 鋁合金MIG焊接組件測試216基于結(jié)構(gòu)應(yīng)力

13、的壽命預(yù)測程序SS Based Life Prediction Procedure Structural stress modeling and life prediction procedures dos and donts 結(jié)構(gòu)應(yīng)力建模與壽命預(yù)測須知 Failure definition 失效定義 Weld line definition 焊線定義 Weld line curvature considerations 焊線曲率因素 Weld representation considerations 焊線描述差異的影響 Load controlled versus displacement

14、 controlled (load shielding) conditions 載荷控制與位移控制(負(fù)載屏蔽)條件217失效定義Failure Definition Fatigue crack 疲勞裂紋 Penetrating thickness t depth 穿透厚度t Extending along weld line in the order of 1-2 t in length 焊線上沿長度方向擴(kuò)展(1-2t) Edge details 邊界細(xì)節(jié) Small specimens t=w 小樣本： t = w Components or large specimens l1 = t 組

15、件或大樣本： l1 = t - Used in all test data correlation 在所有相關(guān)測試數(shù)據(jù)中使用 - Smaller than t: random behavior dominates 小于t：主要是隨機(jī)行為218“Hot Spot” Definitions in HSS Stress Methods versus “Weld Line” Definitions in SS Method熱點(diǎn)應(yīng)力法中 “熱點(diǎn)”的定義與結(jié)構(gòu)應(yīng)力法中 “焊線”的定義 Types “a)”-”c)” 熱點(diǎn)a、b、c Extrapolation procedures 外推程序 S-N cur

16、ve selection 選取S-N曲線 Weld Lines 1 and 2 焊線1、2 Solve simultaneous equations for each 同時(shí)求解方程 Same master S-N curve 使用同一條S-N曲線Weld Line 2: When using shell/plate elements, through-thickness bending is ignored 焊線2：當(dāng)使用板殼單元時(shí)，忽略厚度方向的彎曲應(yīng)力219焊縫表現(xiàn)形式不同造成的影響Effects of Weld Representation on Weld Line Definition

17、Weld Line 1: approximated by Weld Line 2 焊線1被焊線2近似替代Both weld lines are represented 兩條焊線同時(shí)存在 OK for Weld Line 2 (toe failure into attachment plate) 焊線2沒問題(附加板焊趾失效) Mesh-sensitivity develops for modeling weld toe failure into flange 邊緣上焊趾失效時(shí)，模型網(wǎng)格敏感性提高 Not good for loading in x x方向載荷不合適 Good for both

18、weld lines when using coarse mesh (1t or above) 即便使用粗網(wǎng)格，兩焊線模型也能取得較好結(jié)果(=1t) Weld Line 1: two weld lines should be considered for finer mesh 焊線1：兩焊線網(wǎng)格都應(yīng)考慮加密220Weld Line Definitions for Edge Details: Small Lab Specimens versus Structural Joints描述邊界細(xì)節(jié)的焊線定義中：實(shí)驗(yàn)室小樣本與結(jié)構(gòu)接頭221Weld Line Curvature Consideratio

19、ns焊線曲率的影響222Weld Toe Failure Mode vs Weld Representation焊趾失效模式與焊縫表現(xiàn)形式Structural Joint結(jié)構(gòu)節(jié)點(diǎn)Weld Toe Failure: SS are the same for Models A and B焊趾失效：模式A與B結(jié)構(gòu)應(yīng)力相等223A Simple Shear Correction Scheme for Models W/O Representing Weld: A Tubular T Joint無焊縫單元T型連接管的簡化剪切修正方案224Fillet Weld Representations: Small

20、 Fillets or between Drastically Different Thicknesses角焊表示方法：小圓角或厚度突變Solid model should be used to calibrate shell/plate models實(shí)體模型應(yīng)該用于校驗(yàn)殼/板模型225Load-Controlled versus Displacement- Controlled Conditions載荷控制條件與位移控制條件Failure criterion: Through-thickness failure 失效準(zhǔn)則：厚度貫穿失效226S-N Data from TestsS-N曲線測試

21、數(shù)據(jù) Most lab test data are collected under load controlled conditions 大部分測試數(shù)據(jù)都是在載荷控制條件下得到的 Component test data: load shielding (or locally displacement- controlled) often exists 組件測試數(shù)據(jù)：一般存在負(fù)載屏蔽或局部位移控制 e.g., Multiple cracking due to load path change 例如，由于加載路徑的改變引起的多裂紋開裂 Consistent data can only be obt

22、ained with stringent monitoring schemes before load path change occurs 只有加載路徑改變之前采用更嚴(yán)格的監(jiān)控方案，才能得到協(xié)調(diào)的數(shù)據(jù) Actual displacement-controlled conditions are difficult to estimate 實(shí)際上，位移控制條件是很難估計(jì)的 For life estimation purpose, load-controlled conditions should be used to be on the conservative side 對(duì)于壽命估算，保守做法

23、是使用載荷控制227Implications on Fatigue Test Procedures 疲勞試驗(yàn)過程的影響因素 Specimen design, sizing, and loading mode 樣品設(shè)計(jì)、尺寸、加載模式 Failure definition and monitoring procedures 失效定義與檢測程序 Documentation 文檔文件228Failure Criteria for Fatigue Evaluation Using Master S-N Curve and Testing利用主S-N曲線進(jìn)行疲勞評(píng)估的失效準(zhǔn)則及其測試 Through-t

24、hickness failure and load controlled conditions 厚度貫穿失效與載荷控制條件 “Leakage” 滲透法 Before any significant load drop (10%?) 載荷明顯下降之前 Before multiple cracks develop 多裂紋形成之前 Tension tests less sensitive to above 拉力測試對(duì)以上各項(xiàng)不敏感229Stiffness/Compliance Monitoring and Final Failure Determination MIG Weld Example剛度柔

25、度監(jiān)測與最終失效認(rèn)定MIG焊縫為例230Specimen Designs and Loading Modes樣本設(shè)計(jì)與載荷模式 Use simple geometry and loading mode for easy interpretation 盡量使用簡單幾何形狀和載荷模式 Target weld toe failure modes (i.e., sheet failure at weld) 目標(biāo)焊趾失效模式(即薄板焊接失效) Sufficient width to fully contain weld residual stress effects (w/t6) 足夠的寬度以充分考慮焊

26、縫殘余應(yīng)力的影響(w/t6)231Data Documentation/Reporting數(shù)據(jù)文檔/報(bào)告 Load life data 載荷壽命數(shù)據(jù) Peak load and peak displacements at fixed interval 固定時(shí)間間隔的峰值載荷與峰值位移 Individual specimen geometry measurements before testing 試驗(yàn)前單獨(dú)測量樣本幾何尺寸 Grip position measurements 夾持位置測量 Photographs showing failure position and path with r

27、espect to weld position 顯示焊縫位置的失效部位與路徑的圖片 Any anomalies 其他任何異常情況232Importance of Grip Positions Unsymmetric Specimens夾持位置的重要性非對(duì)稱樣本233Fatigue Life Evaluation Procedures Using the Structural Stress Method - Shell/Plate Models結(jié)構(gòu)應(yīng)力法評(píng)估疲勞壽命過程殼/板模型 Construct a FE model 創(chuàng)建有限元模型 Define weld lines (nodal numb

28、ers/weld toe or throat element numbers) 定義焊線(節(jié)點(diǎn)號(hào)/焊趾或焊喉的單元號(hào)) Automated search among all possible weld lines 自動(dòng)搜索所有可能的焊線 Select a few known critical ones 選擇若干關(guān)鍵焊線 Run FE analysis requesting nodal forces/moments 進(jìn)行有限元分析，提取節(jié)點(diǎn)力與彎矩 Post-processing for structural stresses 對(duì)結(jié)構(gòu)應(yīng)力進(jìn)行后處理 Manual calculations for

29、 a few hot spots , or 手動(dòng)計(jì)算幾個(gè)熱點(diǎn)，或者 Automated calculations using SS post-processors 利用結(jié)構(gòu)應(yīng)力處理程序自動(dòng)計(jì)算 Life estimation: 壽命評(píng)估 Constant amplitude loading: go directly to the master S-N curve 常幅載荷：直接使用主S-N曲線 Variable amplitude loading: cycle counting as usual, and damage summation per master S-N curve 變幅載荷：循

30、環(huán)計(jì)數(shù)、主S-N曲線下的損傷累計(jì)234Fatigue Evaluation Example 1: Yagis Tests疲勞評(píng)估算例1Yagi試驗(yàn) Documented in SR202 of Shipbuilding Research Association of Japan (1991) 日本造船聯(lián)合會(huì)文件資料SR202(1991) Constant amplitude loading 常幅載荷 Load controlled conditions 載荷控制條件 Through-thickness failure 貫穿厚度失效 Photographs showing failure pos

31、ition and path with respect to weld position 顯示焊縫位置的失效部位與路徑的圖片 Used in Battelle JIP for correlation with HHI hopper corner test data Battelle JIP使用的HHI測試數(shù)據(jù)235Finite Element Modeling and Structural Stress Analysis有限元建模與結(jié)構(gòu)應(yīng)力分析 Shell element model 殼單元模型 Weld represented with 45 degree inclined elements

32、 焊縫表示為45度傾斜單元 Define weld line (nodes) 定義焊線(節(jié)點(diǎn)) Define weld elements (Shaded) 定義焊接單元(陰影部分) Calculation SS (s) along the weld toe under unit load 沿焊趾計(jì)算單位載荷下的結(jié)構(gòu)應(yīng)力 Determine peak s 確定最大應(yīng)力變化范圍s236Correlate Yagis Test Results with Master S-N Data主S-N曲線與Yagi試驗(yàn)數(shù)據(jù) Calculate equivalent structural stress rang

33、e for each test 計(jì)算等效結(jié)構(gòu)應(yīng)力變化范圍 Plot Yagis test results in terms of Ss-N S-N曲線與Yagi試驗(yàn)結(jié)果237Component Validation Tests組件有效性測試238Component Test Results versus S-N Data from Small Specimens組件測試結(jié)果與來自于小樣本的S-N數(shù)據(jù)2392003 SAE FD&E “Fatigue Challenge” Blind Life Prediction2003 SAE FD&E “疲勞挑戰(zhàn)”壽命盲測 SAE FD&E issued

34、a “fatigue prediction challenge” SAE FD&E發(fā)出了“疲勞預(yù)測挑戰(zhàn)” Actual test results were given after all participants presented their predicted lives 試驗(yàn)結(jié)果將在所有參賽者提交疲勞壽命預(yù)測報(bào)告之后公布 See /weld 詳見：/weld Define weld elements (Shaded) 定義焊接單元(陰影部分) The structural stress method won “The Best Prediction” 結(jié)構(gòu)應(yīng)力法最終獲勝，贏得了“最佳預(yù)測

35、”獎(jiǎng)240Mesh-Insensitivity Demonstration The Structural Stress Method網(wǎng)格不敏感示例結(jié)構(gòu)應(yīng)力法241Comparison of Predicted and Actual Test Results預(yù)測結(jié)果與實(shí)際試驗(yàn)結(jié)果相比較242A 2nd SAE Weld Challenge: Variable Amplitude Loading SAE第二屆焊接挑戰(zhàn)：變幅載荷 Overall specimen geometry: same as before (Challenge 1) 所有測試樣本與上屆保持一樣 Weld end is much

36、 bigger in Challenge 2A (postings at /weld ) 焊縫端部增大很多，詳見/weld 243FE Models:SAE Weld Challenge 2A versus First (Challenge 1) 有限元模型：與第一屆挑戰(zhàn)模型相對(duì)比244Identification of Critical Locations after Searching Two Weld Toe Lines 尋找兩條焊趾線，確定危險(xiǎn)位置Actual failure location: Weld end 實(shí)際失效位置：焊端Observations: 小結(jié) If the wel

37、d ends are big (modeled as posted in the website), weld end failure occurs on 4”x4” 對(duì)大焊端建模，失效網(wǎng)格為4 4 。(見網(wǎng)站模型圖) if the weld ends are as small as those for Challenge 1, failure occurs at 2”X6” weld toe corner 對(duì)小焊端建模，失效網(wǎng)格為2 6 。(第一屆挑戰(zhàn)模型) 245Two Variable Amplitude Loading Cases Tested and Predicted Mean L

38、ives兩個(gè)不同載荷幅度工況試驗(yàn)與平均壽命預(yù)測19.2 times the grapple skidder torque history (GSTH) 27.1 times the grapple skidder torque history抓舉卷揚(yáng)機(jī) 19.2倍、27.1倍的扭矩歷史246Test Results: Failure Locations試驗(yàn)結(jié)果：失效位置247Additional Applications of the Structural Stress Method 結(jié)構(gòu)應(yīng)力法的其他應(yīng)用 Treatment of weld root/throat cracking 焊根/焊喉

39、裂縫的處理 Treatment of multi-axial fatigue 多軸疲勞的處理 Treatment of thermal loading 溫度載荷的處理 Treatment of high-mean loading 高平均載荷的處理 Solder fatigue in electronic packaging 電子封裝中的焊料疲勞248Evaluation of Potential Failure Modes as a Function of Weld Size焊縫尺寸相關(guān)的潛在的失效模式分析249Load-Carrying Fillet Weld: Throat versus

40、Toe Failure承載角焊縫：焊喉與焊趾失效250Failure Mode Definitions Laser Welds失效模式定義：激光焊(a) Sheet failure mode definition for laser welded coupons激光焊板失效定義(b) Definitions of weld toe and sheet failure from weld root 焊趾的定義與源自焊根的板失效(c) Specimen showing “sheet failure” after fatigue test (L1)疲勞試驗(yàn)后的板失效樣本251Equivalent S

41、tructural Stress Range vs N: Sheet Failure vs Interfacial Failure等效結(jié)構(gòu)應(yīng)力范圍與壽命N：板失效與界面失效SS wrt sheet intersection from weld element for interfacial failures源自焊接單元界面失效的交接板結(jié)構(gòu)應(yīng)力焊趾失效焊喉失效252Observations小 結(jié) The same structural stress method can be used for weld root/throat fatigue failure 結(jié)構(gòu)應(yīng)力法同樣可應(yīng)用于焊根/焊喉疲勞

42、失效分析 Need to know weld throat size ? 是否需要焊喉尺寸？ Recommended strategy: prevent weld throat failure at design stage by specifying appropriate weld size 建議在設(shè)計(jì)階段指定合適的焊縫尺寸，以避免焊喉失效 S-N curve should be the same as that for weld toe failures S-N曲線與焊趾失效模式一樣 Other weld types (spot welds, plug welds, etc) 其他焊接類

43、型(點(diǎn)焊、塞焊等) SS method directly applicable 結(jié)構(gòu)應(yīng)力法直接適用 Recommended strategy: eliminate weld or interfacial failure by specifying a minimum weld size 建議指定一個(gè)最小的焊縫尺寸以避免焊縫或界面失效253Treatment of Multi-Axial Fatigue多軸疲勞的處理 An effective stress parameter measuring both normal and shear is needed 需要提供一個(gè)同時(shí)度量法向與剪切的應(yīng)力

44、參數(shù) Local stress based parameters, e.g., by Sonsino and Kuepper (01) 基于局部應(yīng)力的參數(shù)(Sonsino and Kuepper ，2001) Global stress based stress parameters with stress intensity parameters in form of von Mises, Tresca, Principal, e.g., by Maddox and Razmjoo (01) 基于全局應(yīng)力的應(yīng)力參數(shù)與應(yīng)力強(qiáng)度參數(shù)，包括Mises應(yīng)力、Tresca應(yīng)力、結(jié)構(gòu)主應(yīng)力等形式(Mad

45、dox and Razmjoo ，2001) Various theories have been postulated based on local 基于局部假定的各種理論254Applications of the Structural Stress Method in Multi-Axial Fatigue結(jié)構(gòu)應(yīng)力法在多軸疲勞中應(yīng)用 Observations 小結(jié) Crack tends to propagates along weld toe into plate at least for the most part of life time 至少在大部分使用期限內(nèi)，裂紋傾向沿焊趾向板

46、內(nèi)擴(kuò)展 As a result, K is solely defined by normal stress (Mode I ) and in-plane shear (Mode III) K由法向應(yīng)力(I型斷裂)或面內(nèi)剪切應(yīng)力(III型斷裂)單獨(dú)定義 Transverse shear often negligible 忽略橫向剪切效應(yīng)255Structural Stress Definitions for Multi-Axial Loading多軸載荷的結(jié)構(gòu)應(yīng)力定義Through-Thickness Normal Structural Stress厚度截面的法向結(jié)構(gòu)應(yīng)力Through-Thic

47、kness In-Plane Shear Structural Stress厚度截面的面內(nèi)剪切結(jié)構(gòu)應(yīng)力Transverse shear (Fz) is negligible in shell/plate structures 殼/板結(jié)構(gòu)橫向剪切(Fz)忽略不計(jì)256Structural Stress Calculations for A Plate to Tube Fillet (Sonsino and Kuepper, 01)板管倒角的結(jié)構(gòu)應(yīng)力計(jì)算( Sonsino and Kuepper, 2001 )(b) Simplified shell element models of the t

48、ube-to-flange joint modeled with 兩種不同單元尺寸的簡化的管-法蘭接頭殼元模型(c) Structural stress calculation results from this investigation 結(jié)構(gòu)應(yīng)力統(tǒng)計(jì)表257SAE “Weld Challenge” Specimen Loaded in Bending and TorsionSAE“焊接挑戰(zhàn)”中彎曲與扭轉(zhuǎn)工況258SS Based SCFs Calculated Tests by Four Sources 基于結(jié)構(gòu)應(yīng)力的應(yīng)力集中系數(shù)(文獻(xiàn)比較)(a) Multi-axial structur

49、al stress state 多軸結(jié)構(gòu)應(yīng)力狀態(tài)(b) Structural stress based SCFs 基于結(jié)構(gòu)應(yīng)力應(yīng)力集中系數(shù)259Structural Stress Based Approach基于結(jié)構(gòu)應(yīng)力的分析方法 Calculate structural stresses for pure bending, pure torsion, in-phase bending+torsion 計(jì)算純彎曲、純扭轉(zhuǎn)、同步彎扭的結(jié)構(gòu)應(yīng)力 Compute equivalent stress parameter using structural stresses s and s 利用結(jié)構(gòu)應(yīng)力s

50、 和s計(jì)算等效應(yīng)力參數(shù) von Mises Mises應(yīng)力 Tresca Tresca 應(yīng)力 Principle 結(jié)構(gòu)主應(yīng)力 Out-of-phase: 非協(xié)調(diào) Miners rule Miner法則 Modified Goughs ellipse 修正的Gough橢圓方程260Multi-Axial S-N Data: Sonsino(01) & EPRI(02)多軸S-N數(shù)據(jù)(Sonsino, 2001 & EPRI, 2002)von Mises form Mises形式：In-Phase Loading同步載荷261Multi-Axial S-N Data: Sonsino(01) &

51、 EPRI(02)多軸S-N數(shù)據(jù)(Sonsino, 2001 & EPRI, 2002)In-Phase Loading同步載荷262A Modified Gough Ellipse for Incorporating Out-of-Phase Loading Induced Damage 改進(jìn)Gough橢圓方程以包括非協(xié)調(diào)載荷損傷In terms of structural stress ranges: 結(jié)構(gòu)應(yīng)力范圍：von Mises stress range ratio Mises應(yīng)力范圍比Out-of-phase damage 非協(xié)調(diào)損傷svon Mises SS range as a

52、 function of phase angle (or SEQA by ASME):Mises結(jié)構(gòu)應(yīng)力范圍是相位角的函數(shù)(SEQA-ASME)263Modified Gough Ellipse Based Effective Stress Range Multiaxial Fatigue基于改進(jìn)的Gough橢圓方程的有效應(yīng)力范圍多軸疲勞Modified Gough Ellipse:改進(jìn)的Gough橢圓方程：In terms of effective normal structural stress range:有效的法向結(jié)構(gòu)應(yīng)力范圍：To use the master S-N curve:使

53、用主S-N曲線：If = 3, von Mises form implied：= 3，包含Mises形式Fatigue strength ratio between s s and t s loadings 疲勞強(qiáng)度比264Comparison of The Modified Gough Ellipse and Sonsinos EESH Approaches (01)改進(jìn)的Gough橢圓方程與Sonsino EESH方法(2001)比較 Test Data (Sonsino et al, 01) 測試數(shù)據(jù)(Sonsino等，2001) Pure torsion 純扭 Pure bending

54、 純彎 In-phase bending + torsion 彎扭同步 Out-phase bending + torsion 彎扭異步265Applications: The Structural Stress Based Multiaxial Fatigue Criterion應(yīng)用：基于結(jié)構(gòu)應(yīng)力法的多周疲勞設(shè)計(jì)規(guī)范 A material parametermay be introduced at suggestion of Prof. Radaj (05) 建議引入材料參數(shù)(Radaj, 2005) 2007 ASME Div 2: ASME Div2, 2007版 F(), if pha

55、se angle is known 相位角已知-F() F()min=1/sqrt(2) , if not known 相位角未知- F()min=1/sqrt(2) ASMEs “relative effective stress” counting concept and be used for the time being 可暫時(shí)使用ASME的“相對(duì)有效應(yīng)力”計(jì)數(shù)概念 A more effective “path-dependent maximum range” counting procedure has been developed in the SS JIP and will be

56、 first released to JIP participants 一個(gè)更有效的“路徑相關(guān)的最大變化范圍”計(jì)數(shù)程序正在開發(fā)中，不久將發(fā)布第一個(gè)版本。266Example: Battelles Path-Dependent Maximum Range Counting in s -s Plane 算例：ss平面內(nèi)路徑相關(guān)最大變化范圍計(jì)數(shù)法(Battelle)267Interpretation of Low-Cycle Fatigue Data in Master S-N Curve Representation主S-N曲線中低周疲勞數(shù)據(jù)的說明 ASME data focused upon l

57、ow- cycle fatigue ASME中的低周疲勞數(shù)據(jù) Presented either in strain vs life or pseudo-stress vs life 或者以應(yīng)變-壽命形式出現(xiàn)，或者以偽應(yīng)力-壽命形式出現(xiàn) Pseudo-stress: 偽應(yīng)力: E*e or, based linearly extrapolated elastic stiffness slope 或者，彈性剛度斜率的線性外推 Fatigue evaluation using elastic stress analysis in low-cycle regime 利用彈性應(yīng)力分析進(jìn)行低周疲勞評(píng)估 A

58、 pseudo structural stress definition is needed 需要定義偽結(jié)構(gòu)應(yīng)力268Structural Strain Definition結(jié)構(gòu)應(yīng)變的定義Nonlinea bending stresses非線性彎曲應(yīng)力Linear Material Behavio線性材料行為 (b) Non-Linear Material Behavio 非線性材料行為Through-thickness structural stress and structural strain definitions: (a) linear material behavior; (b)

59、nonlinear material behavior 厚度截面的結(jié)構(gòu)應(yīng)力與結(jié)構(gòu)應(yīng)變定義： (a) 線性材料行為；(b) 非線性材料行為269Estimation of Pseudo Elastic Structural Stress in Low Cycle Regime低周階段偽彈性結(jié)構(gòu)應(yīng)力的估算Structural Stress and Structural Strain Relationship結(jié)構(gòu)應(yīng)力結(jié)構(gòu)應(yīng)變關(guān)系270Div 2 Vessel (Flat Head) Tested by PRGDiv2平頭壓力容器測試(PRG)271Div 2 Vessel Tested by A.

60、De Jesus et al (2003) (failure criterion: onset of leakage)Div 2 壓力容器測試(失效標(biāo)準(zhǔn)：發(fā)生泄漏)(A. De Jesus, 2003 )272Cyclic pressure tests of full-scale vessel with various nozzle designs as documented by Inspecta帶有各種噴嘴的壓力容器在循環(huán)壓力下的實(shí)體試驗(yàn)(文檔備查)273Fatigue Evaluation Using Elastic FE利用彈性有限元進(jìn)行疲勞評(píng)估274Treatment of High