Rigid-flexible Coupling Model Research Articles

Rigid—Flexible Coupling Analysis of High Damping Alloy in Gear Pair of Vehicle Transmission

The transmission gear is taken as the research object in this paper, the high damping alloy material is added to the gear to attenuate the vibration when the gears meshes. First, the gear transmission with damping alloy is compared with the traditional gear transmission through the rigid-flexible coupling model in ADAMS, and then the change of gear center acceleration during transmission is analyzed. The damping effect of the high-damping alloy material verifies that the increase of the gear damper can attenuate the vibration, and more effective in high-frequency transmission.

Rigid-flexible Coupling Analysis of Backhoe Hydraulic Excavator Working Device

This paper develops a rigid-flexible coupling approach to predict the dynamic performance of the excavator, including the stress distribution and stress diagram of curves. In order to study the dynamic performance of the excavator during the mining process, the rigid-flexible coupling model of a excavator is established and carried out for dynamics simulation. The results show that the strength of excavator meets the expected requirement and there is a large optimization space. In order to reduce the mass of the excavator's boom, this paper optimizes the design of the boom. Based on the results of the optimization design, the rigid-flexible coupling simulation of the excavator was performed again, which verified that the strength of the boom is sufficient. Simulation results show that the virtual prototype software can effectively predict the dynamic performance of the excavator. This paper provides a solid foundation for further study of the lightweight design of the whole excavator component.

Dynamic Analysis of a Spatial Mechanism Including Frictionless Spherical Clearance Joint With Flexible Socket

In this paper, the dynamic response of a spatial four-bar mechanism with a spherical clearance joint with flexible socket is investigated. Previous research treats the socket as a whole rigid part and neglects the flexibility of the socket. In order to better describe the influence of the spherical clearance joint, a rigid-flexible coupling model of a four-bar mechanism is established, in which the socket of the spherical clearance joint is treated as flexible body. The dynamic responses of this spatial mechanism are discussed for the mechanism with a flexible socket and the case with traditional rigid socket. Furthermore, the effects of clearance size and driving speed are also separately discussed. The results demonstrated that the dynamic response of mechanism is affected by the clearance joint. The socket flexibility can relieve the undesired effects of the clearance on the responses of the mechanism with clearance. The flexible socket acts as a suspension for the mechanism with clearance joint.

Limit cycle judder for new type of drum brake with foldable cam lever actuation device and layered lining

The vibration and noise of brakes have always been prevalent and difficult problems in the automobile industry and its related academic circle. The current study mainly focuses on the groan of the drum brake with a foldable cam lever actuation device strainer. The groan of the limit cycle generated by friction reappears after building its model in the ADAMS. Accordingly, a rigid flexible coupling model with a multi-layer friction plate is built. A simulation analysis shows that the model exhibits good braking stability and can reduce the amplitude of a brake groan through a comparison of the vibration characteristics of the drum brake and foldable cam lever with a conventional cam. A virtual prototyping analysis method for the dynamics characteristics of the foldable cam lever brake is also presented.

A Study on Dynamic Response and Diagnosis Method of the Wear on Connecting Rod Bush

Wear is a typical failure form for mechanical parts of a reciprocating compressor. The clearance of a connecting rod bearing will exceed the normal value due to the wear caused by poor lubrication or abnormal loads. Wear on the small-end bush of a connecting rod (SEBCR) in a reciprocating compressor is still a hard work to be monitored and diagnosed. In this paper, we focus on the study of the dynamic response and diagnosis method on wear fault of SEBCR based on the dynamic simulation and vibration signal analysis. A rigid-flexible coupling model of a connecting rod has been built, and the connecting rod is treated as a flexible body. The clearance between the crosshead pin and the small-end bush of a connecting rod is taken into account. The simulation results show that abnormal clearance will affect the dynamic characteristic significantly, and high acceleration impacts will occur at the reversal points of the crosshead pin. Based on the dynamic response and signal feature extraction, a new diagnosis method calculating the amplitude and change rate of average vibration energy per crank angle to detect the wear fault is proposed. The experiment results on a reciprocating compressor show that the vibration of the compressor crosshead is consistent with numerical simulation results, and the method is capable of detecting the wear fault in real time. Research presented in this paper is significant in providing tools for diagnosing wear fault of reciprocating compressors.

Optimal Design of Automatic Charging Device of Warhead Based on Rigid Flexible Coupling

The traditional loading process of the warhead is finished by hand, the efficiency is low and the quality is not guaranteed, in this paper, we put forward a kind of automation equipment for the warhead. When using the traditional rectangle acceleration control algorithm, the equipment is easy to shake. The charge device is designed in detail, and the dynamics model is established based on rigid flexible coupling. By the simulation and comparison of acceleration algorithm, it is found that the system jitter is weakest when using the S curve algorithm. The S curve algorithm is designed and simplified to five sections, which can avoid jitter obviously in physical testing. The result shows that the optimized algorithm has better control performance, and the rigid flexible coupling model can reflect the dynamic characteristics of the system more accurately, which plays an important role in shortening the development cycle of automatic charging device. This method has a certain reference value for the development of other equipment.

Analysis and optimization of drum washing machine vibration isolation system based on rigid-flexible virtual prototype model

In order to improve the calculation accuracy of vibration response in drum washing machine isolation system, a new CAE method is proposed for dynamics analysis and parameter optimization according to the rigid-flexible coupling technology of virtual prototype. With the vector loop algorithm, the motion differential equation of the vibration isolation system is solved based on Lagrange method, and the key parameters that affect the vibration response are acquired. In terms of simulation research, the modal neutral file (MNF) of the shell body is established by the software ANSYS for modal analysis, and it is exported into software platform ADAMS/Vibration to establish the rigid-flexible coupling model. Through the coupling model, the kinetic characteristics are calculated in continuous excitation frequency domain (0-20 Hz). The experimental verification is accomplished by LMS Test.Lab device, of which results shows that the rigid-flexible coupling simulation method is definitely accurate and feasible. Meanwhile, 15 “hot spots” of the shell body are obtained from the ADAMS/Durability module, which can provide an important basis for structure design. Then, the spring stiffness and damping coefficient is synthetically optimized by sensitivity analysis method with 9 time’s iterative calculation, which has a great significance for product development.

Natural frequency analysis and experiment for 3SPS+1PS parallel hip joint manipulator based on rigid-flexible coupling theory

For analyzing natural frequency of a 3SPS+1PS parallel hip joint manipulator, a rigid-flexible coupling theory is proposed. 3SPS denotes that the PHJM has three legs and each leg type is SPS. 1PS denotes that the PHJM has one constrained leg and the constrained leg type is PS. The rigid finite element method and flexible finite element method are the base of the rigid-flexible coupling theory. Firstly, the basic element models of the PHJM are established based on the rigid-flexible coupling analysis. Secondly, the elastic dynamic models of the flexible legs are established based on the Lagrange equation and flexible finite method. Finally, the rigid-flexible coupling model of the PHJM is assembled by building the relationship between the rigid and flexible elements. Based on the rigid-flexible model, the natural frequency of the PHJM is analyzed. In addition, the effect parameters of the natural frequency are analyzed. The analysis results of the natural frequency show that the natural frequency is symmetric distribution in the working space, and the minimum value of the 1st order natural frequency is 2.3 Hz. The operating frequency (1 Hz) is much lower than the 1st order natural frequency, so the PHJM will not generate resonance and can operate stably. The analysis results of the parameter show that the PHJM has the minimal sensitivity with the effect parameter E and has the maximal sensitivity with the effect parameter H, so the length of the middle leg has the biggest impact on the natural frequency. Natural frequency analysis results have been checked by the hammer test, which verifies the feasibility of the rigid-flexible coupling theory. At the same time, the regression analysis is carried out based on the hammer test results. Using the rigid-flexible coupling theory to solve the natural frequency of the parallel manipulator, the physical meaning is explicit and the modeling process is clear, so the rigid-flexible coupling theory is a universal method.

The Rigid-flexible Coupling Dynamics Analysis of the Powder Filling Quantity Control Mechanism Based on the ADAMS

Powder filling quantity control mechanism is an important part of medicine machine. The geometric model of the filling quantity control mechanism was established by Pro/E based on the NJP1200 capsule filling machine. By Lagrange multiplier method, the equation of movement characteristics was established. And also, the rigid-flexible coupling model of the mechanism was established by ADAMS, Based which, the simulation of displacement, velocity and acceleration curve were obtained. In the end, the change rule of CAM contact force was analyzed. It showed that ADAMS is an effective method in simulation the dynamic characteristics of mechanism.

Numerical and experimental studies on the car body flexible vibration reduction due to the effect of car body-mounted equipment

To study the effect of car body-mounted equipment on the car body flexible vibration, a vertical rigid-flexible coupling model of a high-speed vehicle is established, which includes a flexible car body, rigid bodies for two bogie frames, four wheelsets, and the car body-mounted equipment. The car body is approximated by an elastic beam, with dimensions selected to give similar mass and vertical bending frequency to an existing car body. Model validation is then carried out by comparing results from numerical simulation and on-track test. Using frequency response analysis and ride comfort analysis, parametric studies are undertaken in order to investigate the respective effect of equipment mounting systems on the car body flexible vibration and ride comfort perceived by the passenger. It is found that the equipment behaves as a dynamic vibration absorber on account of its elastic connections to the car body. The stiffness, damping, mass, and installing position of the equipment have a significant influence on the car body flexible vibration. The optimal parameters of the dynamic vibration absorber are given, which can contribute much to the vibration absorption of the car body flexible vibration. Finally, extensive tests on a high-speed test vehicle are conducted to represent a part of results obtained in the numerical study, including modal tests on the car body, component tests on rubber springs used in the equipment mounting systems, and roller rig tests on the vibration absorption performance of the equipment. It is shown that the car body flexible vibration can be effectively suppressed by reasonably suspending the car body-mounted equipment.

Dynamic analysis of a planar slider-crank mechanism with clearance for a high speed and heavy load press system

In dynamic analysis of a slider-crank mechanical with clearance for a closed high speed and heavy load press, elements are generally assumed to be rigid. The dynamic response is considerably changed as joint clearance and flexibility are introduced. Considering the actual features such as clearance, flexibility and friction, a rigid–flexible model is developed into ADAMS. With energy loss taken into account, the IMPACT function is employed by the contact–impact model to describe the contact response between the journal and bearing. The acceleration experiments of the slider-crank at different driving speeds are carried out. We conduct the dynamic simulations of the slider-crank mechanism and compare the numerical results with experimental data. The results reveal that the rigid-flexible coupling model, compared with the rigid model, is more effective to reflect the dynamic response of the mechanical. Meanwhile, the occurrence of motions can be divided into three types: a free flight, a continuous contact motion, and an impact motion. Furthermore, influence of the linkages flexibility, size of joint clearance, and driving speed of crank shaft on the dynamic behavior of the mechanism are studied.

Dynamic Analysis of Dry Frictional Disc Brake System Based on the Rigid-Flexible Coupled Model

A rigid-flexible coupled dynamic model is established to investigate the dynamic behaviors of a disc brake system. The analytical model of the pad includes transverse and circumferential displacements. The disc is modeled using the thin plate theory. A governing equation of the motion of the disc is established. Then the first-order vibration equation is obtained using Galerkin method, considering only the transverse displacement. The friction between the pad and disk among the contacting area is estimated using an exponential model, in which the Stribeck effect is included. Numerical method is applied to reveal the influences of coupling dynamical relationships between the pad and disc on the whole system. The results show that with the variation of disc annular speed, the pad keeps vibrating with small amplitude due to the sustaining variation of the contacting pressure and friction. Stick-slip flutter happens as the velocity is lower than a critical speed and strong movement coupling between elements of the system brings earlier occurrence of the frictional flutter. Besides, for strong movement coupling case, before the critical speed, there are intermittent frequency ranges among which the amplitude is quite higher, which is due to a redistribution of friction and contacting pressure.

Dynamic Characteristic Simulation of Drum Washing Machine Rigid-Flexible Coupling Model

Dynamic Characteristic Simulation of Drum Washing Machine Rigid-Flexible Coupling Model

Research on rigid–flexible coupling dynamic characteristics of boom system in concrete pump truck

Concrete pump truck plays an important role in infrastructure construction and national economic development. In recent years, its boom system becomes longer, and its dynamic and control become more complicated. In order to study the dynamic characteristics of boom system, three dynamic models such as multi-rigid-body model, rigid–flexible coupling model, and rigid–flexible coupling model with equivalent hydraulic cylinder were built in this work. Simulation analysis and experimental analysis were done, and they show that we should not only consider the large-range motion but also consider the small flexible deformation to study the dynamic characteristics of boom system precisely. It provides the theoretical basis to vibration control, trajectory prediction, and life assessment for boom system and such structures.

Multi-objective optimization of the vehicle ride comfort based on Kriging approximate model and NSGA-II

The RMS of weighted acceleration, wheel dynamic load and suspension dynamic deflection are determined as evaluation indices of vehicle ride comfort performance. A multi-body dynamic rigid-flexible coupling model of an in-wheel motor vehicle is built based on the multi-body system dynamics. The ride comfort results of ride comfort simulation and road test are well fitted. A kriging model is created to describe the relationship of vehicle ride comfort evaluation indices and suspension parameters. A multi-objective optimization using NSGA-II is processed using this model, and the vehicle ride comfort performance is improved by using the optimized suspension parameters.

Modeling and Simulation of Flexible Transmission Mechanism with Multiclearance Joints for Ultrahigh Voltage Circuit Breakers

The transmission mechanism, of which the dynamic characteristics determine the reliability of the circuit breaker, is the principal component of the ultrahigh voltage (UHV) circuit breaker. The characteristics of transmission mechanism are quick motion, high sensibility, and high reliability. The transmission mechanism with multiclearance joints present strong no-linear vibration feature which strongly affects the reliability of the UHV circuit breaker. In this investigation, a planar rigid-flexible coupling model of the transmission mechanism considering the clearance joints and the flexibility of components is established by using ADAMS software. The dynamic contact model in clearance joints is performed, based on clearance vector model of clearance joint. Then, the reliability of the model is proved by means of comparing the results of experiments. The simulation results show that the dynamic response of the mechanism is greatly influenced by the clearance and the flexibility of components has a role of suspension for the mechanism. Moreover, the influence of the clearance size, input speed, and number of clearance joints on the dynamic characteristics of the mechanism are also investigated.

Rigid-Flexible Coupling Dynamics Analysis for a Twin-Rotor Piston Engine

Twin-rotor piston engine (TRPE) is a new differential rotary engine, which is still under developing. In this paper, a rigid-flexible coupling dynamics model was established for the prototype TRPE-350. By combining the multi-body dynamics simulating software RecurDyn and the finite analysis software ANSYS, the TRPE′s performances were studied. Vibration analysis for rigid-flexible coupling model was analyzed. The simulation results can be found that the simulated overall changing trends match with the actual movement of the TRPE very well. So it provides a theoretical tool for further optimization and improvement of this engine.

Multi-Body Dynamics Analysis of Anti-Backlash Gear System Based on ADAMS/ Flex

Anti-backlash gear can improve the static transmission precision of system. Besides, the dynamic characteristics of anti-backlash gear system have a significant effect on the performance of overall mechanism, and the torsion spring preload of anti-backlash gear is an important factor to affect the dynamic characteristic. In order to study dynamic characteristics of the anti-backlash gear, a rigid-flexible coupling model of single-stage anti-backlash system was established based on ADAMS / Flex, and the simulation accuracy was compared with the pure rigid model. The effect of the torsion spring preload on frequency response of the anti-backlash system was studied by virtual sweep experiments.

Dynamic Characteristic Analysis of Irregularity under Turnout by Vehicle-Turnout Rigid-Flexible Coupling Model

Finite element model of track in frog zone is built by vehicle-turnout system dynamics. Considering variation of rail section and elastic support, bending deformation of turnout sleeper, spacer block and sharing pad effects, the track integral rigidity distribution in longitudinal direction is calculated in the model. Vehicle-turnout rigid-flexible coupling model is built by finite element method (FEM), multi-body system (MBS) dynamics and Hertz contact theory. With the regularity solution that different stiffness is applied for rubber pad under sharing pad of different turnout sleeper zone, analysis the variation of vertical acceleration of bogie and wheelset, rail vertical displacement and wheel-rail interaction force, this paper proves that setting reasonable rubber pad stiffness is an efficient method to solve rigidity irregularity problem.

Wheel Dynamic Load Optimization of In-Wheel Motorelectric Vehicle Based on Response Surface Method

A multi-body dynamic rigid-flexible coupling model of an in-wheel motor vehicle is built. This vehicle is based on a particular class-A car. An overall investigation of the influence of unsprung mass on vehicle ride comfort is conducted. With the increment of unsprung mass, overall vehicle ride comfort is decreased. The degradation of wheel dynamic load performance is most obvious. Suspension parameters are optimized based on the multi-body dynamic model of the vehicle and Response Surface Method. The suspension deflection and wheel dynamic load of the vehicle using optimized suspension parameters are improved significantly, while the body vertical acceleration increased slightly.