Simulation Analysis of Vibration Shock on Tank Aiming Mirror

Transcription

1 Simulation Analysis of Vibation Shock on Tank Aiming Mio SHOUJUN WU, UOQUAN REN, DONWEI LI Vehicles & electical engineeing Mechanical Engineeing College Shijiazhuang Hebei China Abstact: - Vibation, especially at the cicumstances of accidental falling down, always cause geat damage to tank aiming mio. Theefoe, duing the pocess of designing tank aiming mio we need to conside how to educe the hamful influence of extenal foces. The pape sets up a simplified second ode vibation system and a dynamic model in the ADAMS. We make diffeent simulation analysis on diffeent heights of tank cash.pape studies the change ule of the angula displacement, angula velocity, angula acceleation and contact foce of eflecto when it suffes diffeent impact foce. The study povides an effective eseach means fo vibation analysis of photoelectic equipment. Results show that angle in pitch changes geate than that in azimuth, which not only povides an impotant efeence fo the designe, but also impoves the tank aiming mio s envionmental adaptability. Key-wods:- Tank Aiming Mio, ADAMS, Dynamics Model, Simulation Analysis Intoduction Tank aiming mio belongs to pecise photoelectic equipment, when it woks in battle vibation impact do geat damage to it. Sometimes, it may beakdown. In ode to find the influence of mechanical vibation on tank aiming mio s pefomance, many eseaches use the expeimental methods []. Howeve, test opeation is vey difficult; the cycle is long, with heavy wokload and high cost. It is had to complete dynamic esponse of vibation impact []. H. Wang studied the falling esponse of LCD panel. He also analyzed the change of acceleation and displacement duing dop, along with damping and the sping constant. Results povided a theoy basis fo optimizing stuctue design and enhanced eliability [3]. Q. Li used mathematical tools to expess imaging ule of optical components, esults shown that the tiny optical vaiation will diectly affect the fiing accuacy, and then lowe the wok effectiveness [4]. C.Z. Wang analyzed the model of gun contol system in the tank fie simulato, got the second ode diffeence equation model of contol system [5]. Y.H. Zhang made simulation on a type of infaed lens, extact cuve tend of stess, povided an effective eseach means fo infaed poduct stuctue design [6]. Numeous eseaches on the photoelectic device ae conducted fom theoetical analysis to mathematical modeling and simulation analysis. Howeve, dynamics simulation of the photoelectic stuctue is uncommon. So it is necessay to make dynamic simulation on the tank aiming mio. Aiming at the black field phenomenon of tank dop, we use method of compute simulation to study the vibation and shock on the aiming mio. Fistly, we use ADAMS to make simulation analysis about a cetain type of tank aiming mio duing dop, it can foecast damage of aiming mio when tank dop. As a esult, pape put fowad an effective means to design optoelectonic device stuctue. Othewise, we popose some suggestions to impove the stuctue adaptability to complex envionment. Kinematical Model of Tank Aiming Mio. Simplified Model of Tank Aiming Mio As shown in Fig., the tank aiming mio is installed on top of the tuet, mainly including potective mio, eflecto, objective goup, eflecting pism and eyepiece. They connect each othe though igid fame and elastic gasket. The contol system consists of toque moto, liquid floated gyoscope, as well as mechanical stuctue and sensitive components of electonic. When tank accidentally falls down, the impact foce will pass though the body pat to the top of tuet amo, sight base and sights suppot then finally eaches the pimay mio. Pimay mio, stents, and the oute fame ae connected by igid E-ISSN: Volume 0, 05

2 mateial body and elastic gasket, it can be consideed as a model of mass, sping and damp [7]. The simplified vibation model of the system is shown in Fig.. Reflecto Pism J Y Contol System Objectiv e oup The Eyepiece The Tuet Amo Fig. Simple sketch of tank aiming mio K C M Sight ase M Reflecto I K C Mio acket K C Fig. Vibation model of the system When the tank accidentally fall down, the impact load pass though the body, tuet system and eflex stable aiming system. To facilitate the simulation analysis, we make some assumptions about the model.() Once tank hits the gound, the vehicle does not ebound, so the movement of sight base and lens ebound can be ignoed; () The pimay mio is egaded as a igid body, the system simplified as a fee second ode vibation system, the falling foce passed to the pimay mio by elastic suppot; (3) Sight backet using linea elastic mateial, so that the whole system can be descibed by a set of mass, sping and damp[8].. Kinematics Equation of Reflecto Simplified kinematics equation of float type integating gyoscope can be expessed as I J C H M () y u k () Whee M - Contol toque, M y km I y ; I y y - Input cuent of toque moto; k M - Tansfe coefficient of toque moto; u - Output voltage of angle convete; k - Tansfe coefficient of angle convete. The input signal is angula velocity, output signal is the voltage u of angle convete, tansfe function of the whole system is witten as S H k (3) x s C S S Whee is the output voltage of the system, which is the integation of speed; Static tansfe function is H k expessed as ; Dynamic chaacte of fist C ode system, its time constant is J. C lock diagam of float type integal gyoscope is shown in Fig.3. It can be seen fom the diagam that is the input, is the output. This open system consists of integal gyoscope and angle convete [9]. When the system is stable, is the angula of intenal fame olling aound the axle, which is the integal of, and the output voltage is popotional of. H J S C Fig.3 lock diagam of float type integal gyoscope.3 Theoetical asis Tansient esponse of eflecto can be obtained by solving the kinematics equation. Fom the vibation model in Fig., kinematics equation of the system can be calculated as I 0 t K K K t M 0 I t K K t M (4) Whee I and I ae the otay inetia of eflecto and backet body, K and K ae the sping stiffness coefficient, and ae the slant and S k E-ISSN: Volume 0, 05

3 azimuth angle, M and M ae the slant and azimuth toque[0]. The equation (4) can be ewitten as I K M (5) I 0 I (6) 0 I K K K K (7) K K M M (8) M Regadless of the extenal foce, the homogeneous equation can be expessed as I K 0 (9) Whee I and K ae inetia matix and stiffness matix espectively, constant matix composed of coefficient matix I and K, is a vecto about angula displacement, assuming that K K K, K K K, K K Those ae the elements of the stiffness matix espectively. Thus equation (9) can be witten as I K K 0 I K K 0 K (0) It s the diffeential equation of unconstained system. Whee f t depend on time section of and, the solution can be witten as t, f t f () Whee and signify amplitude. Take the equation () into equation (0) I f t K K f t 0 () I f t K K f t 0 In ode to make the equation () has a solution, thee must be f t K K K K (3) f t I I ecause I, I, K, K, K, K, and ae all eal constant, so must be a eal constant. Fom equation (3) f t f t (4) 0 If equation (4) has vibation solution, thee must be a positive numbe. If synchonous movement is possible, then hamonic function depend on time. That is to say the only possible solutions is f t C sin t (5) WheeC is a andom constant, is the fequency of hamonic vibation, and is the initial phase angle. All these vaiable ae the same fo angle and, C and ae detemined by the initial conditions. Calculating equation () and (5), then coesponding kinematics equation expessed as t f t C sin t (6) t t f t C sin t t Whee and ae aleady taken in C and C espectively, f t and f t depend on time,,,, t t coespond to two kinds of synchonous movement. Equation (6) shows two natual odes vibation mode of two degee of feedom system. In geneal, movement of vibation system usually added by two inheent vibation models, which can be expessed as t t t C sin t C t sin (7) Whee constant C and C, phase angle and ae detemined by the initial conditions. 3 Simulations ADAMS Full Simulation Package is a poweful modeling and simulating envionment that lets you build, simulate, efine, and ultimately optimize any mechanical system. This pape uses the ADAMS/Post Pocesso inteface to simulate, eview, and efine the model []. 3. uild Kinematic Model Fistly, we establish a simplified model of mio by U N 6.0, and then save the file as anothe fomat, finally expot the U model into ADAMS by data exchange inteface. E-ISSN: Volume 0, 05

4 ecause the eflecto and famewok mateials ae of high intensity and stiffness, they can be egaded as igid body collides to common gound. Model of the system is shown in Fig.4. Cleaance contact is defined between mio and inne famewok, setting a hinge on the eflecto. The eflecto mass is.574kg, and backet is.796kg. Inne famewok and oute famewok is also connected though hinge, and the inne famewok can otate in the diection. In ode to simulate movement of eflecto in actual equipment bette, it is necessay to set a sping on the mio to ecove. Fig.6 shows the pitch angle changes with time, fou diffeent cuves ae shown about dop heights. When the height between 0cm to 30cm, the mio can etun to the oiginal location within s afte dop, howeve, when the dop height inceases to 40cm, it ecoves fo a long time. In addition, angle inceases with the incease of dop height, and the influence on pitch angle is bigge than that on the azimuth. It completely shows that the tank cash does geate pitch angle alteation, which povides the focus fo futue eseach. Fig.4 Vibation model of sights The pape uses the following method to simulate tank cash. Assume that the tank dops fom the height of 0cm, 0cm, 30cm and 40cm. Fig.6 Pitch angle of eflecto Reflecto s pitch angle velocity is shown in Fig.7; fom the esults we can see that diffeent heights can poduce diffeent esponses. When the height is less than 30cm, it is obviously that the maximum pitch angle velocity inceases with the incease of dop height. ut when the dop height eaches to 40cm, ecove is a time consuming thing. So we should stengthen the pitching contol on eflecto. 3. Simulation Analysis ecause the pocess of falling down lasts only a moment and the damage happens apidly. The analysis only focuses on instant esponse, including angula displacement, angula velocity, angula acceleation and the contact foce. As shown in Fig.5, the tank dop leads to angula skewing in azimuth. The initial angle is 90, with the incease of dop height, the maximum azimuth alteation also inceases, and it can get back to the oiginal position in the end. Fig.7 Pitch angle velocity of eflecto Angula acceleation esponse is shown in Fig.8; it eaches the peak at about 0.5s, and then dops down quickly. Similaly, the peak value inceases with the incease of dop height. Fig.5 Azimuth angle of eflecto Fig.8 Pitch angle acceleation of eflecto E-ISSN: Volume 0, 05

5 As shown in Fig.9, when dop height is less than 30cm, the velocity of mio eaches to peak in minute and then educes to zeo apidly. Howeve, when the dop height inceased to 40cm, it is difficult to estoe. Moeove, it s obviously that the peak inceases with the incease of dop height. acceleation senso, signal collecto unit and signal conditione, compute, and coesponding softwae system []. Compute Signal Collecto Unit Mio Model Acceleatio n Senso Fig.9 Azimuth angle velocity of eflecto Simila to the esult above, as shown in Fig.0, azimuth angle acceleation is also a pulse signal, pobably achieve peak in 0.5s, and then quickly dop to zeo. In geneal, peak inceases with the incease of height. ounc e Table Fig. Expeimental system As shown in Fig.3 and Fig.4, the Mio model suspends on the suppot though two beaing etaine. Outline of the mio is simila to a ectangle, 55mm long, 65mm wide and 0.75mm thick. Mio mateial is Titanium Alloy, and the suface is coveed with silve lamina, the density is kg/m 3, weight is 5.74N, volume is mm 3, tuning adius is 87.9mm, the pincipal moments of inetia expessed as I =355.69N mm,i =975.9N mm,i 3 =38.9N mm. Fig.0 Azimuth angle acceleation of eflecto Foce geneates fom the contact of mio and suppot, it eflects the amount of impact foce, as shown in Fig.. Fig.3 Entity of eflecto model Fig. Contact foce of eflecto 4 Expeiments 4. Expeimental System In ode to study the effect of vibation on sight s stuctues, the pape sets up a coesponding expeimental system to exploe the influence of vibation on the mio. The whole expeimental system is shown in Fig.. It contains vibation system and signal collect system. Main expeimental equipments consist of mio model, bounce table, Fig.4 Model of the eflecto As shown in Fig.5, the acceleation senso named IEPE thee diections piezoelectic acceleation senso. It is the most popula vibation senso, which has good dynamic popety and poweful oveload esistance. The popety paametes ae shown in Table. E-ISSN: Volume 0, 05

6 4. Expeiment Pocess Vibation shock expeiment condition is shown in Table. Table Vibation shock condition Acceleation /g 0 Time Fequency Tempeatue Humidity 0 7-3ms % Fig.5 IEPE thee diections piezoelectic acceleation senso Table Paametes of IEPE senso IEPE Thee Diections Piezoelectic Acceleation Senso Model DH3E Numbe 3804R Axle:.3 Axle:-3000 Sensitivity Fequency (mv/m s - YAxle:.06 Y Axle:-3000 ) Range(Hz) ZAxle:.5 Z Axle:-3000 Range Span 0000m/s Woking Voltage DC(8-30) Acceleation 5 0 Oveload m/s Woking Cuent (-0)mA Installing Woking 0Hz Resonance Tempeatue (-0-80) Tansvese Installation M5 Thead o <5% Sensitivity Method 5 Hole Oveall Weight 8g Dimensions (mm) As shown in Fig.6, DH590 solid type dynamic data ecode has 8 channels and 00 khz/ch synchonous sampling ate. Its bounday dimension is 80mm 80mm 60mm. Expeimental esults ae shown in Fig.8 and Fig.9. Fig.8 Pitch acceleation Fig.9 Acceleation of thee diections Fig.6 DH590 solid type dynamic data ecode Fig.7 shows the signal conditione in expeiment, it can tanslate and amplify acceleation signal into voltage signal, then convey to the DH590 ecode. Table 3 Contast of acceleation peak Acceleation peak /m s - Expeiment Simulation Relative eo % Y % Z % Fom the contast of expeiment and simulation, we can each a conclusion that the model fits the actual situation, which povides an impotant efeence fo the design and poduction of this type of poduct. Fig.7 Signal conditione/amplifie E-ISSN: Volume 0, 05

7 5 Conclusion This pape uses the ADAMS to establish a dynamic model of a cetain type of tank aiming mio and makes simulation analysis on aiming mio. Conclusions ae as follow () The pape builds the model of tank aiming mio and makes simulation analysis on tank dop; it povides an effective means to study the photoelectic equipment and has geat value fo tank aiming mio stuctue design, so as to impove tank s envionmental adaptability. () The expeimental esults ageed with the simulations, which confims the coectness of the model and povides an impotant efeence fo the design of poduct. (3) y making simulation analysis of the aiming mio dops fom diffeent height. We found that esponse inceases with the incease of height. Othewise, the pitch angle changes geate than the azimuth angle. Thus designe could concentate on the pitch contol at ealy, to insue the poduct with high quality [0] Y.M. Zhang, Mechanical vibation, Tsinghua Univesity Pess, 007. [] F.H. Chen, ADAMS 0 fom intoduction to the maste of vitual pototype technology, Tsinghua Univesity Pess, 03. [] S.L. Wu, Pactical technology of vibation expeiment, Weapon Industy Pess, 993. Refeences: [] Z.. uo, Use of A40- compehensive aiming mio of T-7C tank, Weapon System, 5, 997, pp3-8. [] D. S. Steinbeg, Vibation Analysis of Electonic Equipment, John Wily & Son, 988. [3] H. Wang, Dop esponse analysis of LCD panel, Science and Technology Innovation Heald, 7, 0, pp6-8. [4] Q. Li,.F. Zhang,.P. Yan,.F. Cheng, Simulation of fault of tank s sighting system due to fetting of optical pats, Science and Technology Heald, 3,03, pp -5. [5] C. Z. Wang,.L. Li, Q.L. Wang, C.L. Zhang, J.F. Zhu, Tansition couse model of gunne sight s indexes fo tank fiing simulato, Fie Contol & Command Contol,35,00, pp3-33. [6] Y.H. Zhang, S. Li,.Y. Liu, J. Chen, H.. Li, Dopping simulation and selecting of cushion packaging methods fo a infaed lens, Jounal of Vibation and Shock, 33, 04, pp [7] H.H. Chen,.Q. Wang, Technical compaison between uppe eflecto stabilized sight and lowe eflecto stabilized sight, Acta Amamentaii, 3, 999, pp49-5. [8]. Chen, Q.Y. Zhang, F.Q. Zhao, Demonstation of image-stable pinciple of down-eflection image-stable tank aiming mio, un Launch & Contol Jounal, 003,pp-5. [9] J.F. Zhu,.J. Zhao, Q.Z. Wang, Moden tank fie contol system, National Defense Industy Pess, E-ISSN: Volume 0, 05