Multi-body Dynamics Software Research Articles

Multi-body dynamics and noise analysis for the torsional vibration of a power-split hybrid driveline

Two dynamic models are established to study the torsional vibration and noise characteristics of a power-split hybrid driveline. One is developed using mathematical rotational motion of the driveline components in matrix form. The other dynamic model of the hybrid driveline is built in the multi-body dynamic software ADAMS. The natural frequencies and vibration modes computed from the two methods show a remarkable agreement. Moreover, the noise source identification for the power-split hybrid driveline is also undertaken according to the acoustic measures on the test bench. This study can provide a valuable reference to the development of hybrid electric vehicle in the future.

Analysis for Ride Comfort Evaluation of Passenger Car Traveling on Roads with Generalized Road Profiles and Conventional Speeds

To investigate how the conventional speeds to affect passenger cars ride comfort under a kind of road surface profiles, in multibody dynamics software (ADAMS/Car), a vehicle model was built based on the characteristic parameters of a passenger car. According to the relevant test regulations of ride comfort, the building methods of road surface profiles were discussed. Furthermore, a dynamics simulation analysis of the car was realized by ADAMS/Car and the acceleration-time histories of the seat surfaces X/Y/Z-axis under three conventional driving-speeds were acquired. A special MATLAB program was compiled to calculate the total weighted Root Mean Square (RMS) value by calling the above histories. According to the GB/T 4970-1996, a road test of a passenger car was carried out in the random road surface which equivalent to B level. The car was driven to get the values of total weighted acceleration RMS under three conventional driving-speeds. By comparing the road test result with simulation, the result indicated that the changing trend of total weighted RMS value is consistent as the driving-speed changes, and the ride comfort will decrease when the driving-speed increase. At the same time, it shows that the consistency of the simulation and road test is better.

Dynamic Research with Drivetrain Simulation and Modal Analysis of Wind Turbine Gearbox

The dynamic performance of wind turbine gearbox is very important for measuring the integrated vibration and noise of the whole drivetrain system of wind turbine. The stiffiness and modal parameters of the gearbox will influence the system vibration situation obviously. The wind turbine gearbox is a kind of complicated coupled mechanics; it means the modal analysis on gearbox should consider the coupling effects of the components and define logical damping factors. This paper presents a method to simulate wind turbine gearbox system with the multi-body drivetrain dynamic analysis software. The modal analysis of wind turbine gearbox can be carried out on the basis of the multi-body dynamic theory.

Crankshaft Transient Motion Analysis for Marine Diesel Engine

The multi-body dynamics software EXCITE was used to simulate the marine diesel engine in this paper. The result shown the analysis of the crankshaft transient motion. The purpose provided a theoretical basis on the actual conditions of crankshaft vibration, deformation, stress distribution and improve the design of the crankshaft structure.

A prognostic method for fault detection in wind turbine drivetrains

Abstract In this paper, a prognostic method is presented for fault detection in gears and bearings in wind turbine drivetrains. This method is based on angular velocity measurements from the gearbox input shaft and the output to the generator, using two additional angular velocity sensors on the intermediate shafts inside the gearbox. An angular velocity error function is defined and compared in the faulty and fault-free conditions in frequency domain. Faults can be detected from the change in the energy level of the frequency spectrum of an error function. The method is demonstrated by detecting bearing faults in three locations: the high-speed shaft stage, the planetary stage and the intermediate-speed shaft stage. Simulations of the faulty and fault-free cases are performed on a gearbox model implemented in multibody dynamic simulation software. The global loads on the gearbox are obtained from a dynamometer test bench and applied to the numerical gearbox model. The method is exemplified using a 750 kW wind turbine gearbox. The case study results show that defects in the high- and intermediate-speed bearings can be detected using this method. It is shown that this procedure is relatively simple, yet accurate enough for early fault detection in wind turbine gearboxes.

Research on the Arc-Teeth Synchronous Belt's Tooth Load Distribution Caused by the Machining Error

This paper aimed at the machining error of the arc-teeth synchronous belts tooth ,the 3D model was established with CATIA ,the finite element model of belt was established by HYPERMESH ,and using the multibody dynamic software RECURDYN, the models with different machining errors were simulated by rigid-flexible coupling technology. Systematically studied the changing rule of the wedged stress and the contact stress under the influence of the machining error. So it has certain value to enhance the loading capacity, transmission performance and useful life.

An Implicit Ring Tire Model for Multibody Simulation with Energy Dissipation

ABSTRACT A rigid ring tire model was developed as the c++ module of a free multibody dynamics software. It takes as input the longitudinal profile of the road and is attached to the wheel element of a multibody simulation. It is intended to evaluate the transient behavior of the tire rolling on a deteriorated road profile. It is tailored for, but not restricted to, applications at low camber angles, limited steering and velocity changes, and continuous contact with the road. It is expected to be accurate under excitation frequencies up to 100 Hz and road deformation up to 10 cm. It takes 45 tire parameters and 20 algorithm parameters and is integrated implicitly except for the road profile. The model has been calibrated and validated against a trusted finite element analysis of Michelin XZA-3 tires mounted on a wheel and axle assembly going over rectangular cleats. The resulting curves showed good agreement with the finite element data. The Nelder-Mead optimization process used on the manually determined parameters was able to increase the average coefficient of determination of the 12 test curves from −0.4 to 0.6. Above 20 km/h, that coefficient was better than 0.8 for every test of the vertical force response to cleats. As for the longitudinal forces, only one curve had a coefficient below 0.5. A variable time-step algorithm was also included in the module and found to reduce the simulation time of the test cases by roughly 85%.

Simulation Study on the Combined Harvester with Four Tracked Feet Passing through Ditch Based on RecurDyn

Combine harvester is the most widely used modern forest machinery; tracked and wheeled logging machine is the common stumper. But each type of logging machine has its shortcomings and therefore it is need to develop a combination of tracked and wheeled logging machine. This logging mechanism takes the form of tracked feet while preserving the flexibility of wheeled logging machine, and also it has the obstacle-crossing ability of tracked harvester. The most important indicator of the performance of this new logging machine is its trafficability in soft and uneven road. This thesis uses multi-body dynamic simulation analysis software RecurDyn to build up the 3D model of such four feet tracked logging machine, and analyzes its dynamical process when meeting ditch. Eventually the logging mechanism performance is got. The conclusions provide foundation for design of combined harvester with four tracked feet.

Modeling and Control of a Nonlinear Active Suspension Using Multi-Body Dynamics System Software

This paper describes the mathematical modeling and control of a nonlinear active suspension system for ride comfort and road handling performance by using multi-body dynamics software so-called CarSim. For ride quality and road handling tests the integration between MATLAB/Simulink and multi-body dynamics system software is proposed. The control algorithm called the Conventional Composite Nonlinear Feedback (CCNF) control was introduced to achieve the best transient response that can reduce to overshoot on the sprung mass and angular of control arm of MacPherson active suspension system. The numerical experimental results show the control performance of CCNF comparing with Linear Quadratic Regulator (LQR) and passive system.

A Permanent Magnetic Actuator for 126 kV Vacuum Circuit Breakers

Permanent magnetic actuators (PMAs) have been widely used in medium-voltage vacuum circuit breakers (VCBs) due to their high reliability and controllability. However, a conventional bistable PMA cannot be adopted in power equipment for the transmission voltage level such as 126 kV VCBs directly because of its low-velocity characteristics. The objective of this paper is to propose a multimagnetic circuit PMA to satisfy the high-velocity requirements for 126 kV VCBs. The novel PMA is a bistable and axisymmetric structure, including holding and driving components whose magnetic circuits are separated. Air gaps are specifically designed in the magnetic circuits to improve the velocity performance of the novel PMA. Both static and dynamic characteristics of the novel PMA model have been calculated through finite-element software coupled with multi-body dynamics software. Furthermore, a prototype of the PMA has been developed according to the calculation results. The experimental results on the prototype have shown that the velocity characteristics of the PMA are able to meet the requirements of a 126 kV VCB and agree well with the simulation results.

3D25 Modeling of Shaking Table Systems Aided by Multi-Body Dynamics Software(The 12th International Conference on Motion and Vibration Control)

This paper introduces a modeling approach for the shaking table systems to reproduce the actual dynamics on a computer. In the shaking table system, since the acceleration reproducibility is deteriorated by effects of disturbances, advanced controllers to compensate for the detariorations should be designed to achieve the high precision seismic tests. In the controller design phase, the control performance is generally verified by numerical simulations. Therefore, it is important to construct high precision simulators that precisely simulate effects of disturbances. In addition, the simulator should be required to construct and modify the model such as shaking mechanism and/or specimen. In the modeling approach of this paper, the shaking table mechanism including the specimen is modeled using a multi-body dynamics software, while the control system and physical model of actuator are constructed on a control CAD software. By integrating both softwares, whole dynamics of the shaking table system including the control system can be precisely simulated. In this paper, the overturning moment and reaction force from the specimen are especially simulated, which are main deterioration factors of the acceleration reproducibility. The validity of the simulator have been verified by comparing with experimental results using two different types of laboratory shaking table systems.

차량 전복 방지를 위한 정적 출력 피드백 제어기 설계

This paper presents static output feedback LQ and <TEX>$H_{\infty}$</TEX> controllers for rollover prevention. Linear quadratic static output feedback controllers have been proposed for rollover prevention in such a way to minimize the lateral acceleration and the roll angle. Rollover prevention capability can be enhanced if <TEX>$H_{\infty}$</TEX> controller is designed. To avoid full-state measurement for feedback requirement or sensitiveness of an observer to nonlinear model error, static output feedback is adopted. To design static output feedback controllers, Kosut's method is adopted because it is simple to calculate. Differential braking and active anti-roll bar are adopted as actuators that generate yaw and roll moments, respectively. The proposed method is shown to be effective in preventing rollover through the simulations on nonlinear multi-body dynamic simulation software, CarSim.

Wrist Injuries in Snowboarding – Simulation of a Worst Case Scenario of Snowboard Falls

Snowboarding is one of the most popular winter sports, particularly among adolescents and younger adults. The risk of injuries while snowboarding is higher compared with alpine skiing, with the wrist as the dominant injury region. In contrast to increasing numbers regarding helmet usage, acceptance for wearing wrist protectors is decreasing. To date the market offers a variety of wrist protection products for snowboarding which feature different protective elements. However, there are no minimum performance standards for snowboarding wrist protectors worldwide. Currently a harmonized international standard is under preparation to provide guidelines for minimum safety performance for all wrist protectors used in snowboarding.In the course of this aim, a multi body system (MBS) was developed to acquire further knowledge about the functional requirements of wrist protectors. To evaluate a worst case scenario different falling scenarios of snowboarders were simulated to calculate the resulting loads in the upper extremity. The simulations were carried out using the multi body dynamics software package SIMPACK 9.0 (SIMPACK AG, Wessling, Germany). The comprehensive model contains a human model, a model of a ski slope and a model of a snowboard. The parameterized models adapt to the body height, the body weight and the shoe size of the snowboarder. In this study a model of a 50 percentile adult (1.80 m, 78.4kg) was used.To evaluate a worst case scenario well-known falling situations of snowboarders were simulated. The backward fall on outstretched joints of the upper extremity can be evaluated as worst case scenario.

2B14 Stability Control with Gyro Moment to Improve Rollover Resistance of Narrow Tilting Vehicle(The 12th International Conference on Motion and Vibration Control)

The objective of this work is to address the instability (inverse torque) caused by the tilt actuator in a narrow tilting vehicle by counterbalance it with a stability control system with gyro moment. A four-wheel narrow tilting vehicle was modeled in a multibody dynamics software to conduct a vehicle motion simulation with sharp steers, in order to investigate the gyro effects on the vehicle lateral acceleration (rollover resistance). From the results of the simulation, the critical steer angle when the first vehicle rollover happened without gyro was determined. At critical steer angle, the inner tire displacement from ground was relatively small (wheels were near to the ground) for vehicle with gyro, while vehicle without gyro experienced large displacement (overturn). Also, the vehicle inner wheel loads had become zero (wheels were lifting from the ground) during sharp steeis but was able to recover (the wheel loads) for vehicle with gyro, while vehicle without gyro failed to recover. By adding gyro into the control system, the vehicle had achieved higher lateral acceleration value then vehicle without gyro at the maximum steer angle without rollover. It was proven by the simulation that the stability control system with gyro moment had improved the rollover resistance of the narrow tilting vehicle.

Tyre–road grip coefficient assessment. Part 1: off-line methodology using multibody dynamic simulation and genetic algorithms

A key factor to understand the vehicle dynamic behaviour is to know as accurately as possible the interaction that occurs between the tyre and the road, since it depends on many factors that influence the dynamic response of the vehicle. This paper aims to develop a methodology in order to characterise the tyre–road behaviour, applying it to obtain the tyre–road grip coefficient. This methodology is based on the use of dynamic simulation of a virtual model, integrated into a genetic algorithm that identifies the tyre–road friction coefficient in order to adjust the response obtained by simulation to real data. The numerical model was developed in collaboration with SEAT Technical Centre and it was implemented in multibody dynamic simulation software Adams®, from MSC®.

Ride Comfort Optimisation of Passenger Car Passive Suspension Systems Using ADAMS/ Insight

The arising health problems of ride comfort of passenger cars point out that a lot of effort still has to be put into the design of passive suspension systems.The comfort problem originates from the vibrations transmitted to the driver and passengers caused by the unevenness of the road. This paper reports on an investigation to determine the spring and damper settings that will ensure optimal ride comfort of a passenger car at different speeds. D-optimal designs are developed via multibody dynamics software (ADAMS/Insight) with a model. Evaluation of the comfort improvement was done using an objective function according to the international organisation for standardisation (ISO)2631(1997). The optimised passive suspensions equipped in a passenger car were tested on a test rig in ADAMS/Car. The results show that the vibration levels can be reduced by 47%, generating a drastic comfort improvement.

Binding Force Analysis of Multiple Pairs of Bars Space RCCR Mechanism without Inertia Force

In close to the rigid body condition,to solve the binding force of multiple pairs of bars space RCCR mechanism,first, starting from solving main binding force of three-pair bars space RCCR mechanism by the theoretical analysis, to have obtained the change law of the main binding force without the inertial force (extremely low speed) by using the computational multibody dynamics software ’COSMOSMotion’ and then summed up the equivalent tangential force through the investigation of the simulation data. Finally the concept of equivalent tangential binding force was expanded to 4, 5, 6 pairs of bars space RCCR mechanism.

Dynamic Performance Analysis of Locomotives Based on the Matching between Worn Wheel-Rail Profiles

Wheel profiles in different abrasion stages are tracked and measured for locomotives SS4. They are then matched with rail profiles in the measured wear stability period. In order to contrast the wheel profiles in different abrasion stages, multi-body dynamic software named SIMPACK is adapted to set up a complete dynamics model of locomotives. The influence of wheel profiles in different abrasion stages on the dynamic performances of locomotives is simulated and analyzed. Analysis results state that locomotives using the wheel profiles of typeII have the good stability for their line operation. Locomotives using the wheel profiles of type I have the highest critical hunting speed of 223km/h, which is 54.8% larger than those of wheel profile JM3. When locomotives pass through curve tracks, the value of derailment factor for the wheel profiles of typeII is the smallest and achieves an excellent level, which explains that the wheel profiles of typeII can obtain the good curve negotiation performance.

Study on Dynamic Roll Stability of Articulated Engineering Vehicle Based on Virtual Prototype

Most rollover accidents involve articulated engineering vehicle due to the center of gravity shift when steering. In this paper, a virtual prototype model of a loader as the typical articulated engineering vehicle is built using multi-body dynamics software. The dynamic simulation of steering characteristic under different slop and speed is made and the roll stability is analyzed. The stable working range of the loader obtained from the simulation results can give reference for the drivers selection of vehicle route and safe operation. This paper has a certain meaning for further study of articulated vehicles roll stability.

Research on Mechanical-Electric Brake Simulation in Electric Drive Tracked Vehicle Based on Virtual Prototyping

In order to analyze the process of mechanical-electric brake of electric drive tracked vehicles accurately, a dynamic/kinematic model which based on multi-body dynamics software RecurDyn, and a control system model based on Matlab/Simulink were established. Both of the two models are co-simulated through the software interface technology. The brake process of the drive motor that based on vector control technology is analyzed.