Multi-body Dynamics Simulation Software Research Articles

Advanced diagnostic system for piston slap faults in IC engines, based on the non-stationary characteristics of the vibration signals

Artificial Neural Networks (ANNs) have the potential to solve the problem of automated diagnostics of piston slap faults, but the critical issue for the successful application of ANN is the training of the network by a large amount of data in various engine conditions (different speed/load conditions in normal condition, and with different locations/levels of faults). On the other hand, the latest simulation technology provides a useful alternative in that the effect of clearance changes may readily be explored without recourse to cutting metal, in order to create enough training data for the ANNs. In this paper, based on some existing simplified models of piston slap, an advanced multi-body dynamic simulation software was used to simulate piston slap faults with different speeds/loads and clearance conditions. Meanwhile, the simulation models were validated and updated by a series of experiments. Three-stage network systems are proposed to diagnose piston faults: fault detection, fault localisation and fault severity identification. Multi Layer Perceptron (MLP) networks were used in the detection stage and severity/prognosis stage and a Probabilistic Neural Network (PNN) was used to identify which cylinder has faults. Finally, it was demonstrated that the networks trained purely on simulated data can efficiently detect piston slap faults in real tests and identify the location and severity of the faults as well.

The Machine Design and Parameter Analysis of the Bar Bending which Based on the ADAMS

The three dimensional model of the bar bending mechanism was carried out by using the software Solidegde in this article,and then,import it into the multi-body dynamics simulation software Adams for the dynamic simulation and parameter optimization. Analysis results show that: The non-uniform stress phenomenon on the institutions must be effectively reduce under a appropriate damping ratio coefficient .

Design optimization of diamond wire bead for hard facing stone

The dynamic of the diamond wire single bead moving in the natural stone cutting is considered in this research. The relation between the angle of the tension force declination from the diamond bead long axis and the curvature radius of the saw cut surface is found on the basis of the diamond bead position geometric modeling. This empirical equation allows simplifying the mathematic model equations of the diamond bead wearing. The simplifying equations are put as a basis of interactive model of the diamond bead wearing. The model is built in the multibody dynamics simulation software “MSC.Adams”. This software was chosen as it includes the Cable Module which allows to design and analyze the cable systems in discretized mode. This feature satisfies more the character of the diamond wire working in the cutting of the natural stone. The analysis of the software modeling results shows that the rate of the diamond bead conical wearing does not depend on the cutting force factors and this rate is determined by the saw cut curvature radius only. The relation between these parameters is determined by the empirical equation. The solving of the equation with the characteristic initial data for the hard natural stone cutting is the mean value of the diamond bead conical wear angle. The calculated value of the conical wear angle is the basis of the improvement construction of the diamond wire bead for the hard natural stone sawing.

New Method for Distance-based Close Following Safety Indicator

Objective: The increase in the number of fatalities caused by road accidents involving heavy vehicles every year has raised the level of concern and awareness on road safety in developing countries like Malaysia. Changes in the vehicle dynamic characteristics such as gross vehicle weight, travel speed, and vehicle classification will affect a heavy vehicle's braking performance and its ability to stop safely in emergency situations. As such, the aim of this study is to establish a more realistic new distance-based safety indicator called the minimum safe distance gap (MSDG), which incorporates vehicle classification (VC), speed, and gross vehicle weight (GVW).Method: Commercial multibody dynamics simulation software was used to generate braking distance data for various heavy vehicle classes under various loads and speeds.Results: By applying nonlinear regression analysis to the simulation results, a mathematical expression of MSDG has been established. The results show that MSDG is dynamically changed according to GVW, VC, and speed.Conclusions: It is envisaged that this new distance-based safety indicator would provide a more realistic depiction of the real traffic situation for safety analysis.

Analysis of the Deterioration of Harmonic Local Irregularity on Locomotive Wheel-Rail Vertical Force

By the MATLAB software the article simulated the local irregularity, the new harmonic excitation superimposed on the initial harmonic to simulate track settlement deterioration, the new uplift excitation superimposed on the initial harmonic to simulate track raised deterioration, as the locomotive model external excitation, using the SIMPACK multi-body dynamics simulation software to analyze the influences of the deterioration of harmonic local irregularity on locomotive wheel-rail vertical force, on the basis of the locomotive wheel-rail interaction dynamics index by the locomotive vehicle dynamics theory. The simulation results show that when the deterioration of harmonic local irregularity occurs, even if the amplitude of deterioration is small, which will cause serious deterioration of wheel-rail dynamic response and strong shock and vibration of wheel-rail .The larger amplitude of harmonic local irregularity, the greater of the maximum wheel-rail vertical force. When deterioration of the amplitude exceeds a certain value, the maximum of the wheel-rail vertical force exceedes the limit, which will cause derailment. The wheel-rail dynamic interaction increases with the speed increasing. At the same speed (such as 120km/h), harmonic local irregularity settlement deterioration compareing to harmonic local irregularity raised deterioration, the maximum of the wheel-rail vertical force increases 14.4%. Therefore, local irregularity deterioration or the speed of the locomotive should be strictly controlled.

How Coupler-Knuckle’s Surface S Angle Impact on Coupler Operation Performances

The rail wagon coupler is casting part. Some of foreign products’ error dispersion is significantly greater than domestics’. What influence generated by the results acting on the actual use of performance is still not clear. To this end, this article studied the influence generated by the angle of surface S tangent of coupler-knuckle on coupling connection contour and starting bearing line (referred to as surface S angle) to traction reliability, coupling feasibility and acting force in tangent line, systematically. And authors explored the value ranges of surface S angle in order to ensure the operation performance of coupler-knuckle. Firstly, find the major factors which are associated to surface S angle by studying the movement mechanism of coupling and traction. For example, the maximum level angle of coupler-knuckles, the ability for vehicle to pass the curves, etc. And then, get analytical expression of coupler surface S angle and related factors by means of theoretical derivation. After that, obtain value ranges of surface S angle. Finally, carry on experiments with multi-body dynamics simulation software RecurDyn. On the one hand, eliminate unreasonable value ranges obtained by theoretical derive, on the other hand, analyze the changing rule of the acting force on coupler-knuckle contour. The results prove that, when coupler surface S angle is , the traction performance of coupler is relatively stable, the coupling performance is relatively reliable, the contact force on coupler-knuckle contour is smaller. The conclusion is consistent with surface S angle parameter required by the standard system of Association of American Railroads. The research results above provided the theoretical basis for improving coupler’s manufacturability.

A general method for impact dynamic analysis of a planar multi-body system with a rolling ball bearing joint

Impact affects the dynamic characteristics of mechanical multi-body systems and damages those rotating parts, such as the joint rolling element bearings, which are high-precision, defect intolerant components. Based on multi-body dynamic theory, Hertzian contact theory, and a continuous contact model, this study proposed a modelling method that can describe the dynamic behaviour of planar mechanical multi-body systems containing a rolling ball bearing joint under impact. In this method, the rigid bodies and bearing joint were connected according to their joint force constraints; the impact constraint between the multi-body system and the target rigid body was constructed using a continuous contact force model. Based on this method, the reflection relationship between the external impacts of the mechanical multi-body system and the variation law governing the dynamic load on the rolling bearing joint were revealed. Subsequently, an impact multi-body system, which was composed of a sliding–crank mechanism containing a rolling ball bearing joint and the target rigid body with an elastic support, was analysed to explore the dynamic response of such a complex discontinuous dynamic system andthe relevant relationship governing the dynamic load on the rolling bearing joint. In addition, a multi-body dynamic simulation software was used to build a virtual prototype of the impact slider–crank system. Compared with the theoretical model, the prototype had an additional deep groove ball bearing. That is to say, the prototype model took account of the specific geometric structural characteristics and the complex contact relationship of the inner and outer races, rolling balls, and bearing cage. Finally, the effectiveness of the theoretical method proposed in this study was verified by comparative analysis of the results. The results suggested that the external impact of a mechanical multi-body system was prone to induce sudden changes in the equivalent reaction force on its bearing joint and the dynamic load carried on its rolling balls. This study provided an effective method for exploring the distribution characteristics of dynamic loads on rolling ball bearing joints under working impact load conditions. Moreover, it offered support for the parameter optimisation of geometric structure, performance evaluation, and dynamic design of the rolling ball bearings.

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.

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.

The Dynamics Simulation of Tracked Vehicles on the Hard and Soft Ground Based on the RecurDyn

In order to accurately study a tracked vehicle movement on the ground in hard and soft features, this paper uses multi-body dynamics simulation software RecurDyn tracked vehicle subsystems Track (LM), establishing a three-dimensional multi-body vehicle dynamics model. For tracked vehicles at an inclination of 10 degrees slope, through the soft and hard ground steering process dynamics simulation and comparative analysis. This paper provides an accurate basis for the future in-depth research on Tracked 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®.

Obstacle Performance of Track Robot with Passive Rocker Based on Recurdyn

To solve the instability of track robot in the process of climbing obstacles, a track robot with passive rocker was designed and a three-dimensional model of track robot was developed by Unigraphics NX in this paper. Furthermore, the kinematic analysis was made for obstacle performance of the track robot. The virtual prototype model of the track robot with passive rocker was set up by using the tracked vehicle subsystem of multi-body dynamics simulation software RecurDyn and kinematics simulation for this robot was made. The simulation results verify the feasibility of the machine and provide some theoretical guidance for developing the obstacle performance of track robot.

Design and Motion Simulation Analysis on Automobile Constant Velocity Universal Joints Driving Shaft

the automobile constant velocity universal joint driving shaft is the important component in modern cars, its design is mainly to check the movement compatibility of parts. The constant velocity universal joints driving shaft is designed by three-dimensional solid modeling software UG, and the motion simulation model is build by multi-body dynamics simulation software to investigate the constant speed performance of constant velocity universal joints driving shaft, and check the motion trace of steel ball which is the key component of constant velocity universal joints. The results show that the constant speed performance is good, and the track design of star-like inner race is reasonable.

Lightweight Design for a New Tracked Triangular Wheel Structure

A new tracked triangular wheel structure was introduced. A whole tracked triangular wheeled vehicle model was built in multi-body dynamics simulation software RecurDyn, and its climbing obstacle performance on the dry soil road was simulated. The author put the simulation results as loading conditions of finite element model. Finite element calculation and lightweight design for tracked triangular wheel base frame were completed. The results showed that the weight of the base frame reduced by 69.8%, the structure properties of the base frame improved, and the lightweight design goal was achieved.

Fatigue Life Analysis of Lifting Mechanism Rod Based on Virtual Prototyping and FEM

In order to calculate fatigue life of dump truck lifting mechanism’s structure components, a virtual prototyping model of lifting mechanism was built with Multi-body Dynamic Simulation Software ADAMS. The variation of applied force of lifting mechanism rod with lifting angle was obtained from dynamic analysis of lifting mechanism. A finite element (FEM) model of the rod was established using FEM Software MSC.PATRAN/NASTRAN, and its structural strength was analyzed. On this basis, S-N curve of the rod and linear cumulative damage law was combined to calculate the rod’s fatigue life with Fatigue Analysis Software MSC.Fatigue using nominal stress method. This study provided a reference for the design and improvement of the lifting mechanism.

Simulation Study on Virtual Prototype of Pumping Well System

The virtual prototype simulation of the underground pumping system can’t realize the timing analysis with the ground pumping unit system. In order to solve this problem, the simulation analysis model of the pumped well virtual prototype was established via the multibody dynamics simulation software Adams by analyzing the working characteristic of the sucker rod string. The simulation was in accordance with the dynamic indicator diagram which verifies the correctness of the simulation analysis model of the pumped well virtual prototype and also offers a new analysis method for the underground pump dianamograph and pumping unit balance, etc.

Racing car chassis optimization using the finite element method, multi-body dynamic simulation and data acquisition

This paper presents an optimization methodology applicable to racing car chassis. The proposed procedure is sequentially structured, and starts with analysis of an existing vehicle, goes through an intermediate prototype and finishes with a final design. It is applied to a real case, the redesign of a steel tubular chassis for the ‘Copa de España de vehículos CM’, as part of a full vehicle development. The dynamic response of the existing chassis is modelled using finite element application techniques for structural design and validated with lab tests. In this way, through various modifications using basic static load cases for primary optimization, a completely new design (intermediate) is defined. Then a prototype is built, instrumented and tested in real field conditions (road and circuit). With acquired data from the dynamic behaviour of the car (suspension, steering, engine and transmission, etc.), using multi-body dynamic simulation software, an optimized load case is put forward in order to refine the first prototype. The ultimate goal is a chassis with much increased torsional and bending stiffness, with minimum weight gain, with regard to its interaction with the suspension and steering systems and to the manufacturing feasibility. It is shown that, with an adequate chassis elements configuration, stiffness can be increased by a 300% with just a 5% weight gain. The proposed methodology can be extended to other design (or re-engineering) procedures with rigid limitations in time and resources.

Research of Amplification Frame Optimization Based on Optistruct

The motion of amplification frame of dumper was simulated by multi-body dynamics simulation software ADAMS, and the danger working conditions of amplification frame were calculated. The stress of amplification frame was simulated and analyzed by Optistruct software. The results show that the stress distribution in amplification frame is not uniform and it is big in the middle and small in the edge zeros. The structure of amplification is optimized according to the simulation results. The utilization ratio of the material increases and the cost of production decreases after structural optimization.

Design of a robust controller for rollover prevention with active suspension and differential braking

This paper presents a method to design a robust controller for rollover prevention. Several types of controllers for rollover prevention have been proposed in such a way to minimize the lateral acceleration and the roll angle. The rollover prevention capability of these controllers can be enhanced if the controlled vehicle system is robust to the variation of the height of the center of gravity (C.G.) and the speed of the vehicle. With this idea, a robust controller is designed with linear quadratic static output feedback and parameter sensitivity reduction scheme. Differential braking and an active suspension system are adopted as actuators that generate yaw and roll moments, respectively. The proposed method is shown to be effective in preventing rollover through simulations on the nonlinear multi-body dynamic simulation software, CarSim®.

Matching of Suspension Damping and Air Spring Based on Multi-Body Dynamic Model

By using multi-body dynamics simulation software SIMPACK, the paper completed full vehicle modeling of bus air suspension. In four typical working conditions, body vertical acceleration, suspension working space and dynamic tire load were selected as performance indexes to analyze the matching of suspension damping and air spring. On the basis of comparison of simulation data, a suitable damping was selected for a good matching with air spring in corresponding condition and the performance of the suspension system was improved.