Optimization of New 25A-size Metal Gasket Design Based on Contact Width Considering Forming and Contact Stress Effect

Transcription

1 World Academy of Science, Engineering and Tecnology International Journal of Mecanical, Aerospace, Industrial, Mecatronic and Manufacturing Engineering Vol:6, No:3, 2012 Optimization of New 25A-size Metal Gasket Design Based on Contact Widt Considering Forming and Contact Stress Effect Didik Nuradiyanto, Moc Agus Coiron, Ken Kaminisi, Sigeyuki Haruyama Abstract At te previous study of new metal gasket, contact widt and contact stress were important design parameter for optimizing metal gasket performance. However, te range of contact stress ad not been investigated torougly. In tis study, we conducted a gasket design optimization based on an elastic and plastic contact stress analysis considering forming effect using FEM. Te gasket model was simulated by using two simulation stages wic is forming and tigtening simulation. Te optimum design based on an elastic and plastic contact stress was founded. Final evaluation was determined by elium leak quantity to ceck leakage performance of bot type of gaskets. Te elium leak test sows tat a gasket based on te plastic contact stress design better tan based on elastic stress design. Keywords Contact stress, metal gasket, plastic, elastic A I. INTODUCTION new 25A size metal gasket, wic uses corrugated sape was proposed for asbestos gasket substitution alternative [1]. Te gasket as metal spring effect and produces ig local contact stress to create sealing line wit flanges. Te result confirmed tat te contact stress and contact widt were an important design parameter to optimize te 25A size metal gasket performance. Haruyama, et.all [2] investigated te limits size of contact widt as 25A size metal gasket design parameter. In tis study, te quantitative evaluation of elium leak rate and contact widt of gasket wic as no leak by water pressure test ad been cleared. From te above matter, contact widt can be used as a main parameter to optimize te gasket design. Te leakage can be reduced wit increasing te contact widt. Coiron, et.all [3] provided te contact widt validation by using simulation analysis and te result is compared to experimental using pressure sensitive paper. Nuradiyanto, at.all [4] investigated te optimum 25 A size metal gasket design include forming effect by using simulation analysis. Te 25A size metal gasket was optimized by using L18 Taguci metod. Based on contact widt as design concept and considering contact stress on contact widt including forming effect. According to an elastic condition te optimized gasket was founded. Doctoral student at Department of Mecanical Engineering, Yamaguci University, Japan ( r502wc@yamaguci-u.ac.jp) Mecanical Engineering Department, Brawijaya University, Indonesia ( agus_coiron@ub.ac.id) Graduate Scool of Innovation and Tecnology Management, Yamaguci University, Japan ( kaminisi@yamaguci-u.ac.jp aruyama@yamaguci-u.ac.jp) All new 25A size metal gasket model on te previous study use te assumption an elastic contact stress. Wereas, te plastic deformation occurs in te contact area wen te local stress as reaced. Te use of simulation is beneficial in te design of metal forming operations because it is more cost effective tan trial and error. Te development of ardware and software support te metal forming simulation to define an elastic and plastic contact stress. It is also predict te forces and stresses necessary to execute te forming operation [5]. Press forming is performed to produce gasket sape by a punc forces te initial material to slide into a die. In tis study, we will find te optimum design of New 25A-size metal gasket include forming effect according to an elastic and plastic condition respectively derived from FEM analysis. Te optimum design of te simulation result was tested using elium leak test. Here will be known te gasket performance based on te elastic and plastic design. II. MATEIAL AND METHOD Te gasket material was SUS304 due to its effectiveness in ig-temperature and ig-pressure environment. In order to ensure te properties of te material, SUS304 was initially validated using tensile test carried out based on JISZ2241 [7]. From te tensile test result, te nominal stress (σ) of SUS304 was [MPa], te modulus of te elasticity (E) was 210 [GPa] and te tangent modulus was [MPa]. In te previous study [6], te gasket design based on contact status, wic is contact and no contact, witout considering te distribution of te stress called 0 MPa mode. In te oter and, te gasket design by deleting te contact stress value below of 400 MPa called 400 MPa mode. It was found from te material properties, te yield stress is MPa. In tis study, te gasket design based on an elastic condition we call 0 MPa mode wile it based on a plastic condition is 400 MPa mode. A. Simulation Analysis In tis study, a gasket model is divided into two simulation stage by using two pressing model wic is forming and tigtening simulation. Te optimized design gasket according to an elastic and plastic condition. Flowcart te stage of simulation and optimization te gasket considering forming effect as sown in Fig.1. Bot stages were modeled using finite element metod analysis software MSC. Marc [8]. In te first stage, te dies were assumed as rigid body in bot sides. Using two-dimensional assumptions, te axis symmetric model was adopting a forming process simulation in axial direction on 671

2 World Academy of Science, Engineering and Tecnology International Journal of Mecanical, Aerospace, Industrial, Mecatronic and Manufacturing Engineering Vol:6, No:3, 2012 initial gasket material between te top and te bottom of te dies. Te second stage is te gasket sape produced by mould press is continuity compressed in axial direction to adopt tigtening of te gasket on te flanges. Te virtual gasket model wit various designs was generated by using four basic steps. Tey were te parameterization te models, automatic mesing, computation of preprocessing and post-processing in batc mode and optimization. Firstly, 2-D parameter model is built by utilizing te Solidwork software. To connect drawing data from Solidwork (IGES file) and automatic mesing by using Hypermes, batc command file was built and a NAS file was produced wit tis procedure. Ten te procedure file was configured to obtain preprocessing and running te model on MSCMarc software. Te grapic user interface (GUI) was not appear and te program run command in te background. After te FEM analysis was complete, an output file including analysis results could be generated in TXT file. Te TXT result file was transformed to Microsoft excel by using MACO command. Te output result contains te contact status, stress value, and body force at eac time at every convex position. Calculation of te contact widt versus load on convex position number 1 until 4 is produced wit several step of MACO command. Batc command Initial design 2D axisymmetric model CAD Mesing MSC.Marc Excel L18 Taguci 1. Increasing contactt widt 2. educing clamping load Optimized design for 1. 0 MPa Mode MPa Mode Forming Effect Yes Optimized design Considering forming effect Forming simulation NO Fig. 1 Flow cart te stage of simulation and optimization te gasket considering forming effect Te optimum design was also determined based on reducing te clamping load. It could be denote by using te slope or gradient of te curve of relationsip between contact widt and clamping load (Fig. 2). Te upper and lower contact widt was calculated by adding te value of convex contact position number 1 and 2, 3 and 4 respectively. Te slope of curve was increased; it would be reduce te clamping load. Te slope of curve was built manually by using trend line command in Microsoft Excel. Te process of optimization using L18 Taguci was illustrated as a circulating loop. Due to te optimization design based on increasing contact widt was combined wit considering contact stress, and te optimized design was divided as two modes wic is 0 MPa and 400 MPa modes. Te next circulating loop was generated to fulfill te forming effect by adding forming simulation before te tigtening simulation. Finally te optimized design considering forming effect could be acieved. Contact widt [mm] y = x ² = Clamping Load [kn] Fig. 2 Te slope of te curve of relationsip between contact widt and clamping load B. Press Forming y = 0.007x ² = Press forming was performed to produce gasket sape by a punc forces te initial material to slide into a die. Terefore, te forming effect was considered for gasket design modeling assessment. From te simulation analysis te lack of die fills defect result. Te lack of die fill defect was decreased wit increasing te angle of inner radius. C. Leak Quality Measurement Te scematic diagram of te elium leak measurement device, as sown in Fig. 3, was developed for leak quantity evaluation test of te gasket. In order to evaluate gasket performance, quantitative measurement of leak flow by te elium gas was undertaken. In tis researc, te vacuum metod wic as te igest detection ability in te elium leak measurement was selected and utilized based on JIS Z2330 [9] and JIS Z2331 standard [10]. In te test camber, te elium gas was injected in te outer part of gasket. Te content of residual oxygen in te camber was measured by te oxygen density sensor. Te elium density in te outer part of gasket could be calculated and te measurement was performed wen te oxygen density was below 0.2 [%], and elium density above 99 [%] at te atmospere condition. Using elium leak detector (HELIOT 702D1 ULVAC corporation production), te minimum leak quantity tat could be detected by tis instrument examination 672

3 World Academy of Science, Engineering and Tecnology International Journal of Mecanical, Aerospace, Industrial, Mecatronic and Manufacturing Engineering Vol:6, No:3, 2012 is 1.0E -11 Pa.m 3 /s, and te maximum one was approximately 1.0E -03 Pa.m 3 /s. Measurement was taken from 300 to 500 seconds to avoid te influence of leak flow fluctuation at te time of te initial measurement. For te evaluation of te clamping load and te leak quantity, te leak quantity was measured based on te measurement of elium leak flow quantity. Te variation of clamping load measured were 10, 15, 20, 25 and 30 kn for eac bolt. Te axial load of eac bolt was monitored in order to adjust te appointed axial load error to below 3%. III. ESULT AND DISCUSSION Te simulation result of one of te model in upper contact for 0 MPa and 400 MPa modes is sown in te Fig. 6. Te grapic sows tat for increasing clamping load increase te contact widt. Fig. 3 Te scematic diagram of te elium leak measurement device Te flange used in tis test was a general-purposed flange based on JISB2220 [11] wit 20 K pressure and 25A diameter as sown in Fig. 4. Te flange and joint was welded carefully to avoid a distortion. To avoid te experiment error due to te leakage from te joint of te flange and pipe, te leak flow quantity of joint part was also calibrated. Fig. 4 Appearance of general-purpose 25A flange Clamping load of te flange is caused by te tigtening of flange by bolt. Converting tigtening torque of bolt into te axial load was general procedure in clamping load evaluation. However, te accurate axial load prediction could not be reaced due to various friction coefficient of eac bolt and nut in te clamping. Variation of te clamping load due to clamping order of te bolt also contributed to te inaccurate axial load prediction. In tis researc, axial load measurement was eld by embedding strain gauge to te bolts, terefore te axial load could be directly measured (Fig. 5). Fig. 5 Measurement of clamping load (a) (b) Fig. 6 Te simulation result of te model number 14: (a) 0MPa and (b) 400MPa modes Te L18 matrix was conducted and te slope of te curve of relationsip between contact widt and clamping load as observed values (Y) was calculated for all models as sown in te Table I. TABLE I THE ESULT OF L18 TEST MATIX un# Factor Slope of curve 0 [MPa] 400 [MPa] 1 A 1B 1C 1D 1E 1F 1G 1H A 1B 1C 2D 2E 2F 2G 2H A 1B 1C 3D 3E 3F 3G 3H A 1B 2C 1D 1E 2F 2G 3H A 1B 2C 2D 2E 3F 3G 1H A 1B 2C 3D 3E 1F 1G 2H A 1B 3C 1D 2E 1F 3G 2H A 1B 3C 2D 3E 2F 1G 3H A 1B 3C 3D 1E 3F 2G 1H A 2B 1C 1D 3E 3F 2G 2H A 2B 1C 2D 1E 1F 3G 3H

4 World Academy of Science, Engineering and Tecnology International Journal of Mecanical, Aerospace, Industrial, Mecatronic and Manufacturing Engineering Vol:6, No:3, A 2B 1C 3D 2E 2F 1G 1H A 2B 2C 1D 2E 3F 1G 3H A 2B 2C 2D 3E 1F 2G 1H A 2B 2C 3D 1E 2F 3G 2H A 2B 3C 1D 3E 2F 3G 1H A 2B 3C 2D 1E 3F 1G 2H A 2B 3C 3D 2E 1F 2G 3H Fig. 8 sows te lack of die fills defect result. Te defect is tending occurred on te radius sape of convex contact, bot on 0 MPa and 400MPa modes. No touc Fig.7 sows te main effects is plotted for a visual inspection of eac factor for various level conditions at 0 MPa and 400 MPa modes. Te igest value for slope of curve is supposed as te clamping load reducing. Te main factor of te design is providing te larger contact widt and reducing te clamping load. (b) Fig. 7 Te main effects of eac factor for various levels at slope of curve: (a) 0 MPa and (b) 400 MPa modes (a) Altoug contact widt at 400 MPa mode is smaller tan contact widt at 0 MPa mode, te fact denotes tat contact stress distribution by using 400 MPa mode is larger tan contact stress distribution by using 0 MPa mode. Dividing te mode 0 and 400 MPa is used based on assumption tat te large contact stress creates sealing lines on contact widt [12]. Finally, tis study suggests te optimum gasket design based on results of eac models is sown in Table II. TABLE II OPTIMUM DESIGN OF GASKET AT 0 MPA AND 400 MPA MODES Factor Forming model 0 MPa mode 400 MPa mode OH 3.0 mm 3.0 mm p mm 3.5 mm p mm 4.5 mm p mm 3.5 mm t 1.2 mm 1.5 mm 3.5 mm 2.5 mm 0.35 mm 0.3 mm Fig. 8 Lack of die fills defect result on one of convex contact Using MSC Marc Software analysis founded tat te lack of die fill defect is decreased wit increasing te angle inner radius. Te canges in te angle will cange te radius and lip eigt, see Fig. 9. Tis increased of angle is varied by 0% (θ 0% ), 5% (θ 5% ) and 10% (θ 10% ) from te initial angle, see Fig.10. Te adding 10% of angle sowed te best reduction of te lack of die fill defect. θ θ 1 Fig. 9 Te canges process of te angle to reduce lack of die fills defect result on one of convex contact θ 0% θ 5% 10% Fig. 10 Gasket simulation to reduce lack of die fills defect Finally, te optimum dimensions of dies a metal gasket is obtained see Fig. 11 and Table III. 1 to form 674

5 World Academy of Science, Engineering and Tecnology International Journal of Mecanical, Aerospace, Industrial, Mecatronic and Manufacturing Engineering Vol:6, No:3, 2012 Upper dies 1 1 performance of bot type of gaskets. According to te leaks tat occurred, we find tat te gasket 400 MPa mode was better sealing performances tan 0 MPa mode. Bot types of gasket can be used as a seal, because it did not leak in te elium leak test. 1 Lower dies Fig. 11 Upper and lower dies design TABLE III OPTIMUM DIMENSION OF DIES FO 0 MPA AND 400 MPA MODES Gasket 1 0 MPa Mode MPa Mode In te previous study [3], te qualitative explanation produced by water pressured test is transformed into quantitative value using elium leak test. Terefore, quantitative decision criterion to prevent te leak is determined under te condition of elium leak quantity below te Pa.m 3 /s and it is observed tat te leak by water pressure test did not occur. Fig. 12 Leak measurement test result Te leak measurement result of te proposed gasket is sown in Fig. 12. From te figure sows tat te gasket 0 MPa mode did not leak on te 100 KN axial load wile te gasket 0 MPa mode leak ddi not occur on te 80 KN axial load. Bot types of gaskets sows good performance, because it did not leak at certain axial load. Te gasket 400 MPa sows better sealing performance tan gasket 0 MPa mode. Terefore, te gasket design 400 MPa mode is cosen due to te better sealing performances are desirable because te large contact stress. 1 ACKNOWLEDGMENT Tis project supported by te Strengt of Material laboratory, Yamaguci University, Japan. Te first autor wis to tank for scolarsip support from te Directorate of Higer Education Indonesia cooperated wit Yogyakarta State University. EFEENCES [1] Saeed, H.A, Izumi, S., Sakai, S., Haruyama, S., Nagawa, M., Noda, H., Development of New Metallic Gasket and its Optimum Design for Leakage Performance, Journal of Solid Mecanics and Material Engineering vol. 2, no. 1, 2008, pp [2] Haruyama S., Coiron M.A, Kaminisi K., A Study of Design Standard and Performance Evaluation on New Metallic Gasket, Proceeding of te 2nd International Symposium on Digital Manufacturing, Wuan Cina, September 2009, pp [3] Coiron M.A, Haruyama S., Kaminisi K., Simulation and Experimentation on te Contact Widt of New Metal Gasket for Asbestos Substitution, International Journal of Aerospace and Mecanical Engineering, vol. 5, no. 4, 2010, pp [4] Nuradiyanto D., Coiron M.A., Haruyama S.,Kaminisi K., Contact Widt Evaluation of New 25A-size Metal Gasket Considering Forming Effect, 8 t International Conference on Innovation and Management, [5] Santos Abel D., et.all, Te Use of te Finite Element Simulation for Optimization of metal Forming and Tool design, Journal of Material Processing Energy 119 (2001) pp [6] Coiron M.A, Haruyama S., Kaminisi K., Optimum Design of New 25A-size Metal Gasket Considering Plastic Contact Stress, International Journal of Modeling and Optimization, vol. 1, no. 2, June 2011, pp [7] JIS Z2241, Metod of tensile test for metallic materials, Japanese Standards Association, [8] MSC Marc User manual. [9] JIS Z2330, Standard ecommended Guide for te Selection of Helium Leak Testing, Japanese Standards Association, [10] JIS Z2331, Metod of Helium Leak Testing, Japanese Standards Association, [11] JIS B2220, Steel Pipe Flanges, Japanese Standards Association, [12] Noda N.A., Nagawa L., Siraisi F., Inoue A., Sealing Performance of New Gasketless Flange, Journal of Pressure Vessel Tecnology, vol. 124, 2002, pp IV. CONCLUSION Te optimum design by simulation based on an elastic and plastic contact stress was founded. Forming process for bot metal gaskets mode can be done well. Final evaluation is determined by elium leak quantity to ceck leakage 675