Mechanism-hydraulic Co-simulation Research on the Test Bed o Gun Recoil Mechanism Yuliang YANG, Changchun DI, Junqi QIN, Yaneng YANG Department o Artillery Engineering Ordnance Engineering College Shijiazhuang China (Beijing) a yyl_liang@sina.com Abstract: In the test bed o recoil mechanism, recoil mechanism completed the recoil and counterrecoil process, pushed by hydraulic cylinder. The test bed consisted o the mechanical system, the hydraulic system and the electrical system. Based on ADAMS sotware and EASY5 sotware, the dynamic model and hydraulic system model o test bed were respectively built. On the basis o these models, mechanismhydraulic co-simulation model o test bed was built, and co-simulation analysis was developed. The movement curves o piston rod and pressure curves o accumulators were obtained. The study will provide a theoretical basis or the engineering application o test bed. Key-Words: -recoil mechanism; test bed; dynamic model; plug-in valve; hydraulic system model; cosimulation. Introduction Recoil mechanism is a core part o gun system, and gun perormance depends largely on it. Gun recoil mechanism varied in types and structure sizes. Ater the decomposition and combination in army and actories, some simple methods were usually used to check up the perormance o recoil mechanism, or example artiicial boost, gas leakage detection, liquid leakage detection and so on. These methods were not universal and quantitative, which were diicult to meet the need o various guns maintenance and detection. In this paper, a new type test bed o recoil mechanism was studied on the structure and principle analysis. Based on virtual prototyping technology, cosimulation model o test bed was built and analyzed. Test bed structure o recoil mechanism The test bed o gun recoil mechanism consisted o the mechanical system, the hydraulic system and the electrical system. In the test bed o recoil mechanism, recoil mechanism completed the recoil and counterrecoil process, pushed by hydraulic cylinder. The design index o the test bed was that the maximum recoil and counterrecoil velocity o recoil mechanism should be above m/s. The mechanical system consisted o the recoil mechanism, the test bench, the connecting seat, the orce sensor, the high speed hydraulic cylinder and so on, shown in Figure. For the dierent types o recoil mechanism, back support bushings, ront support bushings and sleeve can be adjusted to expand the application scope. The hydraulic system consisted o hydraulic pumps, displacement sensors, plug-in valves, highpressure accumulators, low pressure accumulators, ilters, relie valves, check valves, the data acquisition and control system and so on. High pressure accumulators and plug-in valves were used to provide large low o luid oil in the dynamic impact process. The data acquisition and control system was used to receive test signals o sensors and control the valve components. E-ISSN: 4-349 4 Volume, 5
The electrical system consisted o the operational console, the PLC control system, the device protection circuit and the laser printer. PLC control system was the control core o the electrical system. The operational console was used to set orces limits and positions limits. When the resistance was above normal more than percent, the device protection circuit started to run, at one time the test bed stopped and saved test data. The laser printer was used to print test data and test curves, ulilling the data output unction. 3 4 5 6 7 8 9 Figure Test bed o recoil mechanism -recoil mechanism; -test bench; 3-back support bushings; 4-back support; 5-ront support; 6-ront support bushings; 7-sleeve; 8-connecting seat; 9-orce sensor; -high speed hydraulic cylinder 3 Test bed modeling Take a certain type o gun recuperator or example, mechanism-hydraulic co-simulation model o test bed was built based on virtual prototyping technology. 3. Dynamic Model Based on dynamic simulation sotware ADAMS [, 3], dynamic model o test bed was built, o which recoil mechanism was recuperator, shown in Figure. Dynamic model mainly consisted o three parts, hydraulic cylinder, recuperator and connecting device. recuperator connecting device hydraulic cylinder Mq +Φ q = Q + F Φ (,) qt = g () Where, q was the generalized coordinate array; M, Φ, Q were respectively the generalized mass q matrix, the Jacobi matrix o constraint equations Φ (,) qt = and the generalized orce matrix. F g was the generalized orce matrix o contact orce F, which can be calculated by the entity impact model based on impact unction [5]. During the recoil process, recuperator provided [4, recoil resistance 5]. Recuperator was hydropneumatic, o which operational principle was shown in igure 3. counterrecoil recoil rod rod recoil luid high-pressure gas Figure Dynamic model o test bed Lagrange multiplier method was used to build dynamic equations automatically by ADAMS sotware, and impact hinge was introduced in the orm o equivalent impact orce to dynamic equations [4]. The dynamic equations o the test bed were described as ollow. Figure 3 Operational principle o recuperator In the recuperator, gas was the storage medium, and liquid acted to transmit orce and sealing gas. During the recoil process, gas in the recuperator was compressed due to the movement o the E-ISSN: 4-349 43 Volume, 5
counterrecoil rod, which produced recoil resistance to the piston through the liquid. Change o gas pressure was described by the polytropic process. n n p γ = p γ = cos nt () Where, P P were respectively the instantaneous pressure and the initial pressure o gas in the recuperator; γ γ were respectively the instantaneous volume and the initial volume o gas in the recuperator; n was the polytropic exponent, depended on the heat transer condition and the piston velocity. Regardless o riction, recoil resistance can be described as ollow [6, 7]. ( γ F = A p = A p γ )n (3) Where, A was the work area o recuperator piston. Introduced the equivalent length o initial recuperator volume l = V / A, then the volume o any gas was V= V Ax = A ( l x). Equation (3) can be described F n l = A p l x (4) 3. Hydraulic system model As the hydraulic cylinder has a high speed during the work process o test bed, so the high hydraulic low was needed. Plug-in valves and accumulator were used in the hydraulic system model to achieve the goal. 3.. Plug-in valve model Four plug-in valves were used in the hydraulic system model, work principle o plug-in valve was shown in Figure4. -valve core; -spring; 3-valve sleeve; 4-seal Figure 4 Structure o plug-in valve Through the above structural analysis, the mathematical model o plug-in valve can be obtained. Regardless o valve core gravity and riction, orce equation o valve core o plug-in valve was: pa A A + pa B B pxax kx ( + xl) F = mx L L (5) Where, p A, p B, px were respectively the chambers pressure o A, B and X; A A, A B, AX were respectively the eective action areas o the three chambers; k was the spring stiness; x was the initial spring compression; x L was the valve core displacement; m L was the valve core mass; F was the steady-state low orce, F = cπdaxl( pa pb)cosα, c was the valve oriice low coeicient, α was the valve oriice taper Flow equation o plug-in valve was: ( pa pb) Q = cπdaxlsinα (6) ρ 3.. Hydraulic system model Based on hydraulic simulation sotware EASY5, hydraulic system model o test bed was built, shown in Figure 5. The work process o test bed consisted o three stages, energy storage stage, stroke stage and return stage. E-ISSN: 4-349 44 Volume, 5
9 6 7 3 5 8 4 4 5 3 6 9 8 7, 8- hydraulic pump;, 7-ilter; 3, 6- relie valve; 4-check valve; 5- high pressure accumulator; 6, 7,, - plug-in valve; 8, 4 throttle valve; 9- hydraulic cylinder; -ADAMS interace; 3-low pressure accumulator; 5-reversing valve; 9-tank; -control system () Energy storage stage: the hydraulic pumps and 8 were open to provide oil to high pressure accumulator 5 at the same time. () Stroke stage: when the pressure o high pressure accumulator reached a certain value, open the plug-in valves 6 and, two hydraulic pumps and the high pressure accumulator provided oil to the let chamber o hydraulic cylinder, pushing the piston rod move to a high speed. The hydraulic oil in the right chamber o hydraulic cylinder 9 lowed through the plug-in valve into low pressure accumulator 3. (3) Return stage: when the stroke stage inished, closed plug-in valves 6 and, opened plug-in valves 7 and, the piston rod o hydraulic cylinder returned to the initial position by the recuperator. Hydraulic cylinder is the coupled component o dynamic model and hydraulic system model. The two models are connected by the ADAMS Mechanism module o hydraulic cylinder. Based on the hydraulic system model, when the ADAMS mechanism module was added, the connection between EASY5 sotware and ADAMS sotware was completed [8], and the co-simulation model o test bed was built. 3.3 Co-simulation model Figure 5 Hydraulic system schemes The driving orce o the piston rod was obtained based on the hydraulic system model built in EASY5 sotware. The displacement and velocity o the piston rod were obtained based on the dynamic model built in ADAMS sotware. Parameters relation o the dynamic model and hydraulic system model was shown in Figure. 6. dynamic model parameters, constraints and orces o dynamic model velocity and displacement hydraulic orce hydraulic system model pressue calculation equations low calculation equations state parameters o hydraulic system Figure 6 Parameters relation o the dynamic model and the hydraulic system model 4 Simulation analysis o test bed Based on the mechanism-hydraulic co-simulation model, co-simulation analysis was developed. When the pressure o the high pressure accumulator was MPa, the plug-in valves 6 and were open, and the stroke stage started. When the counterrecoil rod reached a certain position, the return stage started. 4. Displacement and velocity o piston rod Based on the co-simulation model, displacement and velocity curves o piston rod in one work E-ISSN: 4-349 45 Volume, 5
process were obtained by simulation analysis, shown in Figure 7 and Figure 8. l/m.5 -.5.5.5 Figure 7 Displacement o piston rod v/m s - - -.5.5 Figure 8 Velocity o piston rod The piston rod o hydraulic cylinder and counterrecoil rod were astened together, so the two parts had the same displacement and velocity. To save the simulation time, the initial pressure o high pressure accumulator was set to MPa, so the stroke stage started irstly. As can be seen rom Figure 7 and Figure 8, the maximum recoil velocity o counterrecoil rod was.443m/s in the stroke stage(~.848s), and the maximum counterrecoil velocity o counterrecoil rod was.339m/s in the return stage(.848~.63s), which were greater than m/s. The test bed spent.63 second to complete one test process. 4. Accumulator pressure During the simulation process, the initial pressure o high-pressure accumulator was set to MPa, based on the co-simulation model, the pressure curves o high-pressure accumulator and lowpressure accumulator in one work process were obtained by simulation analysis, shown in Figure 9 and Figure. p/mpa p/mpa.5.5.5.5.5 Figure 9 Pressure o high-pressure accumulator.5.5.5.5 Figure Pressure o low-pressure accumulator As can be seen rom Figure 9 and Figure, during the stroke stage, the pressure o highpressure accumulator was reduced rom MPa to.49mpa, and the pressure o low-pressure accumulator was raised rom.3mpa to.76mpa. When the stroke stage inished, two hydraulic pumps simultaneously provided oil to the highpressure accumulator, which was raised to MPa at.98s. at the same time, the pressure o lowpressure accumulator was reduced to the initial pressure. From the simulation analysis above, the test bed spent about s to complete the recoil and counterrecoil process. 5 Conclusion The structure and operational principle o the test bed o recoil mechanism were discussed, which consisted o the the mechanical system, the hydraulic system and the electrical system. Based on the ADAMS sotware and EASY5 sotware, the dynamic model and hydraulic system model o the test bed were built. Then the mechanism-hydraulic co-simulation model o test bed was built, and co-simulation analysis was developed. The maximum recoil and counterrecoil velocity o counterrecoil rod were greater than m/s, which indicated that the test bed design met the initial perormance index. The test bed spent about s to complete the recoil and counterrecoil process. The test bed can be used to improve the E-ISSN: 4-349 46 Volume, 5
perormance detection and maintenance support, and the study will provide a theoretical basis or the engineering application o test bed. Reerences: [] Changzhi JIA, Renxi HU, Xiuju DU, et al. Study on Design Evaluation o Recoil System o Guns Based on Virtual Prototyping Technology[J]. Journal o System Simulation. 7, 9(): 746-749. [] Ruilin WANG, Yongjian LI, Junnuo ZHANG. Modeling Technology and Application o Small Arms Based on Virtual Prototype[M]. National Deense Industry Press, 4. [3] Jianrong ZHENG. Introduction and Rise o Adams Virtual Prototyping Technology [M] Beijing: Mechanical Industry Press,. [4] Wei LI, Jisheng MA, Changchun DI, et al. Simulation Research on Dynamics o Ramming System and Action Reliability Considering the Randomness o the Parameters[J]. ACTA ARMAMENTARII,, 33(6): 747-75. [5] Msc Company. Adams/ View user guide[db/cd]. Caliornia: Msc Company, 5. [6] Peilin ZHANG, Guozhang LI, Jianping FU. Fire System o Sel-propelled Artillery [M]. Beijing: Weapon Industry Press,. [7] Shuzi GAO, Yunsheng CHEN, Yuelin ZHANG, et al. Gun Recoil System Design [M]. Beijing: Weapon Industry Press, 995. [8] Lin LIU. Conceptual Design and Simulation o Power System o Recoil Test Machine with Muzzle Impact [D]. Shijiazhuang: Ordnance Engineering College,. E-ISSN: 4-349 47 Volume, 5