1、作業(yè) A12疲勞Shape Finder作業(yè) A12 目標培訓手冊目標:目標在于完成一個連桿模型的疲勞分析(ConRod.x_t). 具體地,我們將分析兩個載荷環(huán)境(environments): 1) 4500 N的恒定振幅載荷 Fully Reversed ;2) 4500N的任意載荷.February 2, 2004Inventory #0020108-2ANSYS Workbench - SimulationShape Finder. . . 作業(yè)A12 起始頁培訓手冊從發(fā)射臺進入DS.選擇 “Geometry From File . . . “ 打開文件“ConRod.x_t”.當 D

2、S 啟動后, 點擊右上角 X 關(guān)閉向?qū)Р藛?February 2, 2004Inventory #0020108-3ANSYS Workbench - SimulationShape Finder作業(yè)A12 過程培訓手冊改變單位為公制metric (m, kg, Pa ).1.“Units Metric (m, kg, Pa, C, s)”1.確認材料設置為結(jié)構(gòu)鋼 “Structural Steel”.2.3.在geometry 欄點擊“Part 1”.如果不是,那么點擊“Material”并“browse”.2.3.February 2, 2004Inventory #0020108-4AN

3、SYS Workbench - SimulationShape Finder. . .作業(yè)A12 過程培訓手冊4.選擇 “Structural_Steel” 材料,然后點擊 Open.4.February 2, 2004Inventory #0020108-5ANSYS Workbench - SimulationShape Finder. . .作業(yè)14 過程培訓手冊施加如下邊界條件 (看下頁):February 2, 2004Inventory #0020108-6ANSYS Workbench - SimulationShape Finder. . .作業(yè)A12 過程培訓手冊5.6.點擊

4、環(huán)境 Environment 欄.點擊連桿表面顯示5.6.7.插入一個力載荷.“RMB Insert Force”8.從detail窗口改成“Components” 并使 “Z = - 4500N”.7.8.February 2, 2004Inventory #0020108-7ANSYS Workbench - SimulationShape Finder. . .作業(yè)A12過程培訓手冊9.點擊環(huán)境欄Environment.10. 點擊連桿表面顯示9.11. 插入一個圓柱殼支撐.10.“RMB Insert Cylindrical Support”從Details of “Cylindric

5、al Support” 窗口:12. 設置 Radial=“Fixed”, Axial=“Free”,Tangential=“Free”11.12.February 2, 2004Inventory #0020108-8ANSYS Workbench - SimulationShape Finder. . .作業(yè)A12 過程培訓手冊13. 點擊環(huán)境欄Environment.14. 點擊連桿表面顯示13.14.15. 插入一個固定支撐.“RMB Insert Fixed Support”15.February 2, 2004Inventory #0020108-9ANSYS Workbench

6、- SimulationShape Finder作業(yè)A12 求解設置培訓手冊向solution(求解)添加結(jié)果:16. 點擊 solution 欄.16.17. RMB Insert Stress Equivalent (von Mises).17.18. RMB Insert Deformation Total.18.February 2, 2004Inventory #0020108-10ANSYS Workbench - SimulationShape Finder作業(yè)A12求解設置培訓手冊插入fatigue tool:19. 點擊 solution 欄.19.20. RMB Inser

7、t Fatigue Fatigue Tool.20.February 2, 2004Inventory #0020108-11ANSYS Workbench - SimulationShape Finder作業(yè)A12 求解設置培訓手冊從 Details of “Fatigue Tool” 窗口:21. 定義疲勞強度因子(Fatigue Strength Factor) (Kf) 為0 .8 (描述的材料數(shù)據(jù)表示光滑試件和在役構(gòu)件).22. 定義對稱循環(huán)載荷(fully reversed loading)以 21.建立交互應力循環(huán).22.23. 定義應力壽命疲勞分析(由于是全反載荷(fully

8、reversed loading) 而不是平均應力,所以不需 23.24.要平均應力理論).24. 定義Von Mises 應力以便和疲勞材料數(shù)據(jù)比較.February 2, 2004Inventory #0020108-12ANSYS Workbench - SimulationShape Finder作業(yè)A12 求解設置培訓手冊向 Fatigue Tool添加結(jié)果:25. 插入 “Safety Factor”(安全系數(shù)):RMB Insert Fatigue Safety Factor.25.從 Details of “Safety Factor” 窗口:26. 設置設計壽命 Design

9、 Life 為1e6循環(huán)次數(shù).26.February 2, 2004Inventory #0020108-13ANSYS Workbench - SimulationShape Finder作業(yè)A12 求解設置培訓手冊 向 Fatigue Tool添加結(jié)果(續(xù)):27.插入 “Fatigue Sensitivity”(疲勞敏感性):RMB Insert Fatigue Fatigue Sensitivity27.從 Details of “Fatigue Sensitivity” 窗口:28.定義一個最小基本載荷變化幅度為50% (一28.個2250N 的交互應力)和一個最大基本載荷變化幅度為

10、200% (一個 9000N的交互應力) .February 2, 2004Inventory #0020108-14ANSYS Workbench - SimulationShape Finder作業(yè)A12 求解設置培訓手冊 向 Fatigue Tool添加結(jié)果(續(xù)) :29. 插入 “Biaxiality Indication”:RMB Insert Fatigue Biaxiality Indication29.Solve(求解)February 2, 2004Inventory #0020108-15ANSYS Workbench - SimulationShape Finder作業(yè)A

11、12 結(jié)果培訓手冊查看結(jié)果 點擊并畫出總體變形“Total Deformation”.February 2, 2004Inventory #0020108-16ANSYS Workbench - SimulationShape Finder作業(yè)A12 結(jié)果培訓手冊點擊并畫出等效應力結(jié)果 “Equivalent Stress” .February 2, 2004Inventory #0020108-17ANSYS Workbench - SimulationShape Finder作業(yè)A12 結(jié)果培訓手冊點擊并畫出對于設計壽命為1e6的循環(huán)次數(shù)的安全系數(shù) “Safety Factor”.Febr

12、uary 2, 2004Inventory #0020108-18ANSYS Workbench - SimulationShape Finder作業(yè)A12 結(jié)果培訓手冊點擊并畫出關(guān)于一個最小基本載荷變化幅度為50%和一個最大基本載荷變化幅度為200%的疲勞敏感性結(jié)果“Fatigue Sensitivity”.February 2, 2004Inventory #0020108-19ANSYS Workbench - SimulationShape Finder作業(yè)A12 結(jié)果培訓手冊找出最大基本載荷變化幅度為400%的百年化壽命的敏感性,注意,必須重新 計算以得到新的敏感性結(jié)果.Februa

13、ry 2, 2004Inventory #0020108-20ANSYS Workbench - SimulationShape Finder作業(yè)A12 結(jié)果培訓手冊點擊并畫出雙軸指示結(jié)果 “Biaxiality Indication”.注意,接近危險區(qū)域的應力狀態(tài)接近單軸的(.1.2) ,因為材料特性是單軸的.回想,一個0 biaxiality, 與單軸應力一致;為-1時,為純剪切;為1時為純雙軸狀態(tài).February 2, 2004Inventory #0020108-21ANSYS Workbench - SimulationShape Finder作業(yè)A12 求解設置培訓手冊插入第二個

14、 fatigue tool以分析 4500N的任意載荷. 假設我們具有從構(gòu)件試驗獲得的應變評估結(jié)果,并且知道平谷結(jié)果中的200與施加的4500N的載荷想對應:30. Highlight the solution branch.30.31. RMB Insert Fatigue Fatigue Tool.31.February 2, 2004Inventory #0020108-22ANSYS Workbench - SimulationShape Finder作業(yè)A12 求解設置培訓手冊從 Details of “Fatigue Tool 2” 窗口:32. 定義一個疲勞強度因子( Fatig

15、ue Strength Factor) (Kf)為 0.8 (描述的材料數(shù)據(jù)表示光滑試件和在役構(gòu)件).33. 定義疲勞載荷,源自一個比例歷程,選擇包括應變評估結(jié)果的在時間范圍內(nèi)的比例歷程文件(瀏覽并打開 “SAEBracketHistory.dat” 文件).32.34. 定義比例系數(shù)為0.005(我們必須規(guī)范化載荷歷 33. 程,以便使FEM載荷能夠與載荷歷程文件中的比34. 例系數(shù)匹配):February 2, 2004Inventory #0020108-23ANSYS Workbench - Simulation1FEMload 1000lbs= 1 FEM load = .005 1

16、000lbs 200 strain gauge 200 strain gauge Shape Finder作業(yè)A12 求借設置培訓手冊從 Details of “Fatigue Tool” 窗口 (續(xù)):35. 定義Goodman理論以計算貧乏軍應力影響.36. 定義signed Von Mises應力,用于和疲勞材料數(shù)據(jù)進行比較 (使用signed是由于Goodman理論處理負的和正的平均應力形式不同).37. 定義bin size為32 (雨流Rainflow 和損傷矩陣 Damage matrices 是 32x32).35.36.37.February 2, 2004Inventory

17、 #0020108-24ANSYS Workbench - SimulationShape Finder作業(yè)A12 求解設置培訓手冊向 Fatigue Tool 2添加結(jié)果:38. 插入壽命“Life”:1. RMB Insert Fatigue Life38.39. 插入安全系數(shù)“Safety Factor”:RMB Insert Fatigue Safety Factor39.從 Details of “Safety Factor”窗口:40. 設置設計壽命 Design Life為1000次循環(huán)s.40.February 2, 2004Inventory #0020108-25ANSYS

18、 Workbench - SimulationShape Finder作業(yè)A12 求解設置培訓手冊向 Fatigue Tool 添加結(jié)果(續(xù)):41.插入疲勞敏感性 “Fatigue Sensitivity”:RMB Insert Fatigue Fatigue Sensitivity41.從 Details of “Fatigue Sensitivity” 窗口:42.42.定義一個最小基本載荷變化幅度為50% (交互應力為 2250N) 和一個最大基本載荷變化幅度為200% (交互應力為 9000N).February 2, 2004Inventory #0020108-26ANSYS W

19、orkbench - SimulationShape Finder作業(yè)A12 求解設置培訓手冊向 Fatigue Tool 添加結(jié)果(續(xù)) :43. 插入雙軸指示 “Biaxiality Indication”:RMB Insert Fatigue Biaxiality Indication43.44. 插入雨流矩陣 “Rainflow Matrix”:RMB Insert Fatigue Rainflow Matrix44.February 2, 2004Inventory #0020108-27ANSYS Workbench - SimulationShape Finder作業(yè)A12 求解

20、設置培訓手冊向 Fatigue Tool 添加結(jié)果(續(xù)):45.插入損傷矩陣 “Damage Matrix”:RMB Insert Fatigue Damage Matrix45.從 Details of “Damage Matrix” 窗口:46.設置設計壽命 Design Life為1000 次循.46.February 2, 2004Inventory #0020108-28求解solveANSYS Workbench - SimulationShape Finder作業(yè)A12 結(jié)果培訓手冊查看結(jié)果 點擊并畫出壽命結(jié)果 “Life”.February 2, 2004Inventory #0020108-29ANSYS Workbench - SimulationShape Finder作業(yè)A12 結(jié)果培訓手冊點擊并畫出設計壽命為1000次循環(huán)的安全系數(shù) “Safety Factor”.February 2, 2004Inventory #0020108-30ANSYS Workbench - Simulation注意,比例系數(shù)是為了使其滿足1000 月壽命的比例系數(shù) .如果載荷歷程與構(gòu)件一個月時間的經(jīng)歷一致,那么損傷和FS就和設計壽命的1000次循環(huán)一樣. 注意,盡管計算只有112載荷塊的壽命,但需要的比例系數(shù)只有0.