2 0 0 2 2
D ev elopm ent of A n aly s is T echnique for improv em ent in s treng th and s afety of A ut om otiv e s e at s tructure
. 2 0 0 1 1 2
. 1 1. 1 2. 2. 5 1. 5 2. 11. 14 1. 15 1) 15 2) T rack 20 3) 22 2. 31 1) 31 2) Luggage 35. 47 48 Ab str act 49
Li s t of F ig ure s F ig. 1 Clas sification of aut om otiv e seat F ig. 2 Dev elopm ent proces s of seat sy stem F ig. 3 F.E.M odel of Back F ram e F ig. 4 F.E.M odel of Recliner F ig. 5 F.E.M odel of Slidin g Lat ch F ig. 6 F.E.M odel of Rail P art F ig. 7 F.E.M odel of Body Block F ig. 8 Specim en of S eat F ram e F ig. 9 Configuration of F MVS S 202 H ead Restraint F ig. 10 F.E.M odel of Head Rest Sim ulation F ig. 11 B oundary Condition of Head Rest Sim ulation F ig. 12 Deform ed Shape F ig. 13 Stress Concentration F ig. 14 Boun dary Condition of T rack P art F ig. 15 Deform ed Shape of T rack P art F ig. 16 configuration of F MVS S 210 S eat Belt An chorages T est F ig. 17 Ph ot ograhp of F MVS S 210 S eat Belt Anchorag es T est F ig. 18 Load History Curv e & Load Con dition F ig. 19 F.E.M odel of F MV S S 210 F ig. 20 Ph ot ograph of S eat Belt Anchorag es T est F ig. 21 Stress Distribution F ig. 22 Deform ed Shapes F ig. 23 F MVS S 210 W ith Cent er Rail F ig. 24 Stress Distribution F ig. 25 Deform ed Shapes w ith Cent er Rail F ig. 26 Configuration of F MVS S 201 H ead Im pact T est F ig. 27 F.E.M odel of Head Rest & Im pact or F ig. 28 Initial Configuration of F MV S S 201 H ead Rest Im pact T est F ig. 29 Deform ed Shapes of S eat under Head Rest Im pact Simulation F ig. 30 M ax imum A cceleration of H ead Rest F ig. 31 Configuration of Lu gg age Block Im pact T est
F ig. 32 Im itial Configuration for Lug gage T est Sim ulation F ig. 33 Im posed Initial Velocity for Lu gg age T est Sim ulation F ig. 34 Deform ed Shape & M ax. Displacem ent F ig. 35 Deform ed Shape on T op View F ig. 36 Ph ot ograph of Lu gg age T est F ig. 37 V arialble Design of Hing e Bracket F ig. 38 Comparison of M ax. Displacem ent Graph F ig. 39 M ax. Displacem ent of each T ype F ig. 40 Ph ot ograph of Lu gg age T est (D T ype) Li s t of t able s T able 1 M at erial of S eat F ram e T able 2 M at erial Dat a T able 3 P aram atic study of Lug gag e Block Im pact Sim ulation
. 1.1 (Seat ) (Chair )... FMVSS (Federal Motor Vehicle Safety Stadard) ECE.,,,...,,,. - 1 -
1.2 Fig.1,, 1,,,,...,,. (Foam ),, (Floor ),, (Seat Belt Anchorage)..,...,. (head rest ).,. (padding ). (back rest ). T Ek., - 2 -
,.. F ig. 1 Classification of Aut om otiv e S eat - 3 -
Fig. 2 Development Process of Seat Sy stem - 4 -
. 2.1 1) (back frame) (recliner ).,.,,,. (spring ) (wire). - 5 -
CAD Mode l F.E. Mode l (2), (shell). /., 10 mm. - 6 -
(3),.,,. CAD Mode l - 7 -
F.E.Mode l (4),,.. Fig. 7,. - 8 -
F.E. Mode l of ra il pa rt (4),,.. - 9 -
(a) F.E. Mode ling of uppe r body block (b) F.E. Mode ling of uppe r body block Fig. 7 F.E.Model of Body Block - 10 -
2.2.. T able 1. T able 1 Material of Seat Frame SP CC (S CP 1) - seat fram e - bracket SPH C (SHP 1) - seat fram e - bracket SAPH440 (SA PH45) - seat m echanism - box leg ST KM - cu shion - back m ain frm - 11 -
1) -. (a) Spes ime n of Plate (b) Spes ime n of Pipe Fig. 8 Specime n of Seat Frame - 12 -
T able 2 Material Data M at erial Yeild Stress [kg/ m m 2 ] Ultim ate Stress [kg/ mm 2 ] Youn g ' s M odulu s [kg/ m m 2 ] P oission ratio T hickn ess [m m ] SP CC 20.89 30.63 21.0 0.3 2.6 SPH C 29.5 37.25 21.0 0.3 2.3 SAPH440 35.44 50.35 21.0 0.3 2.6 ST KM 36.79 40.84 21.0 0.3 1.5-13 -
III.,,, (T rack ),,..,,. (Explicit Dynamic Code) PAM - CRASH. - 14 -
3.1 3.1.1 1) (FMVSS 202) 38 kgf m., 102 mm. 890N. Fig. 9 Configur ation of FMVSS 202 Head Restraint - 15 -
2) Fig. 10,,. Fig. 10 F.E.Model of Head Rest Simulation - 16 -
,. (hinge bracket ).. - : Rotation Free/ Direction Fixed - : All Fixed Fig. 13 (node). - (quasi- static) 140 msec Ramping Up. Fig. 11 Boundary Condition of DS2 Head Rest Simulation - 17 -
3) FMVSS 202,. Fig. 12 Deformed Shape - 18 -
,. Fig. 13 Fig. 13 Stress Concentration - 19 -
3.1.2 (T rack) Fig. 14 1,449 1292., 1,300 kgf Fig. 14 Boundary Condition of T r ack Part - 20 -
2) Fig. 15 250, 500, 1000, 1300kgf. 1,300kgf.. Fig. 15 Deformed Shape of T rack Part - 21 -
3.1.3 1) (FMVSS 210) (NHT SA ; National Highway T raffic Safety Administration ) FMVSS 210. (lap belt system ) (body block) 22.24kN (static load), (lap and shoulder belt system ) 13.35kN. 5 15 o. 20... 16 210.. 17. (load cell)., (zig ). - 22 -
Fig. 16 Configuration of FMVSS 210 Seat Belt Anchor ages T est Fig. 17 photograph of FMVSS 210 Seat Belt Anchorages T est - 23 -
2) (Finite Elment Model) / HYPERMESH T M.,,. FMVSS 210.(Fig. 8) (Contact ) (shell element ), (bar element ).,, (rigid body ). Fig. 18. (Inertia effect ). Fig. 19.. Fig. 18 C 20. A 3000 lb +10 o B 5000 lb +10 o C 29000 lb 0 o Fig. 18 Load History & Load Condition - 24 -
Fig. 19 F.E.Model of FMVSS 210 Fig. 20 Photograph of Seat Belt Anchor ages T est - 25 -
3) (1) Fig. 22 (center rail). RR _d RR. (floor ) (leg ) RR. Fig. 21. RR. Fig. 21 Stress Distribution - 26 -
(a) Side & T op view at 0ms (b ) Side & T op view at 80ms (c) Side & T op view at 120ms Fig. 22 Deformed Shapes - 27 -
(2). RR. Fig. 23. Fig. 23 FMVSS 210 With Center Rail - 28 -
Fig. 25. Fig. 24 RR.,. Fig. 24 Stress Distribution - 29 -
(a) Side & T op view at 0ms (b ) Side & T op view at 80ms (c) Side & T op view at 120ms Fig. 25 Deformed Shapes w ith Center Rail - 30 -
3.2 3.2.1 1) (FMVSS 210) FMVSS. (interior ) FMVSS 201. A,B (pillar ). 172 mm, 6.8kg (head foam ) 15mph 3m s 80g. F ig. 26 Configuration of F MV S S 201 Head Im pact T est - 31 -
2). FMVSS 201 Fig. 27 (impactor ). 172 mm. 7,468. Fig. 27 Finite Element Model of Head Rest & Impactor Fig. 28 Initial Configuration of FMVSS 201 Head Rest Impact T est - 32 -
3) Fig. 29.,.. Fig. 29 Deformed Shapes of Seat under Head Rest Impact Simulation - 33 -
3ms Fig. 30 22.346 g. Fig. 30 Maximum Acceler ation of Head Rest - 34 -
3.2.2 Luggage 1) (ECE No. 17-7) RV,,.. ECE No.17., 50 ± 2 kph (luggage) 100 mm, 150 mm.,. Fig. 31 Configur ation of Lugage Block Impact T est - 35 -
2)... Fig. 41 (SRP ; Seating Reference Point ). 50 mm 5. 300 mm 20 mm 18 kg. 50 km/ h 100 mm. - 36 -
Fig. 32 Initial Configuration for Luggage T est Simulation Fig. 33 Imposed Initial Velocity for Luggage T est Simulation - 37 -
3) Fig. 34. 219 mmqus 100 mm 119 mm.. Fig. 36. - 38 -
(a ) T op Veiw (b) Side View Fig. 34 Deformed Shape & Max. Displacement - 39 -
(a) 0 msec (b) 30 m sec (c) 60 msec Fig. 35 Deformed Shape on T op View - 40 -
(a ) Rear View (b) Side View Fig. 36 Photogr aph of Luggage T est - 41 -
3.2.3 Luggage. Fig. 37 A,B,C,D 4. Fig. 37.. A, B. C B 2.6 mm 3.2 mm D B Fig. 37.. - 42 -
Fig. 37 Param atic Study of Hinge Br acket T able 3 Paramatic Study of Luggage Block Impact Simulation Hing e T ype Recliner Brack et Original T ype Hin ge Bracket None A T ype Recliner SP CC 2.3t B T ype Recliner SA PH 2.6t C T ype Recliner SA PH 3.2t D T ype Recliner SA PH 2.6t & Rear Pipe - 43 -
1) 2, (Double Recliner ). SPCC 2.3t SAPH 2.6t, SAPH. SAPH 3.2t (D T ype), SAPH 2.6t (C T ype),. SAPH 2.6t (1.5t ) (D T ype). Fig. 38 D. Displacement Regulation Original A T ype B T ype C T ype D T ype 100 mm 219 mm 249 mm 74.8 mm 80.4 mm 50.5 mm Fig. 38 Comparison of Max. Displacement Graph - 44 -
(a ) A T ype (b ) B T ype (c) C T ype (d) D T ype Fig. 39 Max. Displacement of Each T ype - 45 -
D.. Fig. 40 Photograph of Luggage T est (D T ype) - 46 -
.,.. 1) - 2) 3) -. 4). 5) - 200% -, 4 50% D- T ype. - 47 -
[1] "Optimum Design and Impact Characteristics for Automobile Seat". Heon Young Kim, Sang Keun Lee, Jung Jae Kim, Pacific Conference on Automotive Engineering, 1997. [2] CRASH AMD- Vol. 169/BED- Vol 25, Cr ashw orthines s and Occupant Pr otection in T r an sportation Sy stem s ASME 1993. [3] Seating sy stem T est, FMVSS NO 208 NHT SA USA. [4] Seating Belt A ssembly Anchor ages T est, FMVSS NO 210 NHT SA USA. [5] "Injury Mitigating Benefits of an Inflatable Shoulder Belt for Seat Integr ated Application", Advacnes in Safety T echnology 1999(1999-01- 0085). [6] "Studies with Belt Integr ated Vehicular Seat s", Anthony Sances, Kenneth J. Saczalski, Envir onm ent Research and Safety T echnologies, Inc., Newport Beach, California. [7] "Autom otiv e Belt s to Seat", Philip W. Leistr a III, Autom otiv e Body Interior & Safety Sy stem s, IBEC ' 96. [8] "Belt Integr ated Vehicular Seat Rear Impact Studies", Kenneth J. Saczalski, Joseph L. Burtion, Paul R, Lw eis, T odd K. Saczalski, Peter E, Bar ay, Seoul 2000 FISIT A World Automotive Congress [9] "A dvanced Restr aint Sy stem s for Rear Seat Occupant s", Dr. Harald Zellm er, Bag & Belt ' 98, 5th International Akzo Nobel Symposium on aut om otiv e Occupant Restraint Sy st em s. [10] "CAE Simulation of FMVSS 207/ 210 T est For Seat Belt Anchor ages", Grish Bapu, Shekar Erasala, Saleem Humayun, Autom otiv e Body Interior & Safety Sy stem s, IBEC ' 95 [11] "Preent Status of Impact Analy sis in Japan", K. Andoh, H. Niizeki, HANPM '95-48 -
D e v e lopm e nt of A n aly s is T e c h n iqu e f or im prov e m e nt in s tre n g th an d s afety of A u t om otiv e s e at s tru c tu re Yoo Sung Yong D ep artm ent of M echanical E ng ineering Graduate S chool, K ang won N ational Univ ers ity U sing FEM (Finite Element Method) can provide u seful inform ation s to design a new car seat and can r educe the overall design cost and time. T his paper deal w ith the safety capability of the seat sy stem while occupant s are sitting on the seat in case of v ariou s impact condition s : fr ontal, rearw ar d, and ruggage impact. T he structur al analy sis of car seat sy stem by the finite element method. T he load- deformation characteristics of seat fram e are simulated accor ding to the test r equirem ent s by FMVSS. T hr ee dimen sion modeling technique is applied to the component s of the seat frame. Comparison w ith test r esult s show s the validity of this analy sis technique. T he design of a car seat sy st em r equir es the structur al optimization for the w eight, strength, and performance. - 49 -