288-2846395 mme.modares.ac.ir 2 * 2 - -2 ghlia530@modares.ac.ir 45-4 *... (). ).. ( 394 03 : 394 0 : 395 0 : Experimental and numerical analysis of impact on steel curved panels Ahmad Bidi, Gholamhossein Liaghat *, Gholamhossein Rahimi Department of Mechanical Engineering, Tarbiat Modares University, Tehran, Iran * P.O.B. 45-4 Tehran, Iran, ghlia530@modaress.ac.ir ARTICLEINFORMATION ABSTRACT OriginalResearchPaper Received24December205 Accepted20February206 Available Online 20 April 206 Keywords: Steel panel Radius of curvature Drop test Plastic deformation ).[]. [2] The low velocity impact behavior of steel panel with different curvature is investigated experimentally. Numerical analysis is used for test results verification. In experimental method drop impact test apparatus is used so three different heights for falling weight are considered. Also, three different panel curvatures for experiment are used. Two important parameters measured are maximum acceleration and maximum plastic deformation of panel. A high speed accelerometer is used for measuring the impactor acceleration. Also, the permanent plastic deformation is measured with numerical measurement system attached to the drop test apparatus. Experimental analysis with three different radius of curvature is modeled with numerical analysis, the numerical analysis is used for further panel curvatures so the panel behavior is estimated in a wide range of panel curvatures. The results in numerical analysis and test (if available) show good agreement when compared together. the results show that increasing the panel radius of curvature will increase impactor acceleration and will decrease the plastic deformation of panel, but if the radius of curvature is increased more and more, then the impactor acceleration will not increase further and will be nearly constant, on the other hand, plastic deformation of the panel will not be increased further when the panel radius of curvature is increased more.. - Side crash -.... Pleasecitethisarticleusing: : A. Bidi, Gh. Liaghat, Gh. Rahimi, Experimental and numerical analysis of impact on steel curved panels, Modares Mechanical Engineering, Vol. 6, No. 4, pp. 28-288, 206 (in Persian)
Fig. Geometry and dimension of ST4 panels with 0.7 mm thikness,(a) Infinit radius plate (flat plate), (b) 300 mm in radius panel and (c) 0 mm in radius panel 0/7 ST4 mm (b) ) (a) Fig. 2 Impact test apparatus 0 mm (c) 300 2 - - 2.[3]. () [4]..[5] - [6] [7]. [8] 36.. ) 2 20 220 4 ( -2 - - - - () 3000 0.7 3 46. 40 30 20... 2. 3 - DH-36 2- RR ST 4 3- Drop Weight Impact Testing 46395 282
. - 3-2. c b.. 4.. 0 ).. 5. 4. 0.8-4- 2 4 - - - 04-0.7.. 220 20 ) 200 200 220 20 60. 9 :200-0002 -. E 80. GPa, E t 00 MPa, 70 MPa Y E t, E.. 30 0 Y. 5-5- 2 - - 5-2 64 85 mm 2 (. 55 3... 46. 46. 40 30 20 () = 20cm = 2.0 m s =2 = 30cm = 2.4 m s = 30cm = 2.8 m s. () - -2 353b02. pcb - 2-2.. Fig. 3 Head of impactor details 3 - Impactor head 2- Ccomputer Numerical Control (CNC) 283 46395
Fig. 4 Loading fixtures, (a) Three fixtures, (b) flat fixture details (b ) (a ) 4 a (m/s 2 ) 250 200 50 00 50 0-50 0.05 0.25 0.45 0.65 t(sec) Fig. 6 acceleration-time diagram for flat plate, drop height=30 cm 30 6. 6. 0.0 Fig. 5 panel with 0 mm radius of curvature. (a) before impact (b) after impact with H=30 cm (b) (a) 0 5 30 30 6... 46395 284
- - 3 900.() 200-700 - 300-0 30 30. 900. [9] - 2-3.. 0.7.. 2. 5. 9. 340 [] 2 46 Table mechanical properties of steel panel from simple tension test (tone/mm 3 ) 7.85E-9 (MPa) 8E4 0.3 (MPa) (MPa) 00 0.25 5- SOLID64 70-2-5-2. 7. - 3. 3 2 - - 85.. -. - 4 0.9 -. -2. ) -3 ( -4 - - Plastic Deformation(mm) 45 40 35 30 25 20 5 25 35 45 55 H(cm) Fig. 7 plastic deformation vs. panel radius in experiment 7 - Catia 2- Ansys 3- Ls.Dyna 4- Time step 285 46395
. 0.03 0.25. 980-5- 3 - - 5-3 -. 0.2 6 m/s 2-4 - - 4 0.6 6 6 9. 0.2 (). 430 6375 8-3- 3 8 ()... - 4-3 2.. ) ( z 2. 3 [0] 2 Table 2 mechanical properties of impactor [0] PR (MPa) E 0.3 200E3 (tone/mm 3 )RO 9892E-7 250 200 a (m/s 2 ) 50 00 50 0-50 0 0. 0.2 0.3 t (s) Fig. 9 Acceleration history for m=46 kg, H=30 cm (numerical analysis) ) 30 cm 46 kg 9 Fig. 8 Numerical modeling, total model including plate and impactor 8 - Node Set 2- Initial condition 3- Automatic surface to surface contactmm 46395 286
a (m/s 2 ) 290 260 230 200 70 Test (H30) Test (H20) Test (H40) Numerical (H30) Numerical (H20) Numerical (H40) 40 00 300 500 700 R(mm) Fig. Acceleration vs. panel curvature variation comparation at three heights. - 4-4. 2 20. 7. - 2-4 0.. () - 3-4 ( ). 700 00.(), 300. 0 500 30 40... () () 2 9 6 - d (mm) 35 30 exprimental numerical 300 250 25 a (m/s 2 ) 200 20 0 250 500 750 000 R(mm) Fig. 2 plastic deformation (d) vs. panel radius for H=20 cm(numerical and test comparation) 20 2 50 00 0 500 000 500 2000 2500 3000 R (mm) Fig. 0 Acceleration vs. panel curvature variation 0 287 46395
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