scholarly journals Numerical Investigation on Handling Stability of a Heavy Tractor Semi-Trailer under Crosswind

2020 ◽  
Vol 10 (11) ◽  
pp. 3672 ◽  
Author(s):  
Qianwen Zhang ◽  
Chuqi Su ◽  
Yi Zhou ◽  
Chengcai Zhang ◽  
Jiuyang Ding ◽  
...  
Keyword(s):  
Lateral Displacement ◽  
Aerodynamic Characteristics ◽  
Lateral Acceleration ◽  
Yaw Rate ◽  
Body Dynamics ◽  
Crosswind Stability ◽  
Computational Fluid Dynamics Cfd ◽  
Multi Body ◽  
The Relationship ◽  
Lateral Area

Due to the large lateral area of the trailer and variable road conditions, the handling stability of a heavy tractor semi-trailer under crosswind is very important for road safety. In this present work, numerical simulation is performed to study the crosswind effects on handling stability of a tractor semi-trailer. The aerodynamic characteristics of the tractor semi-trailer under different crosswind were computed by computational fluid dynamics (CFD). Then, mathematical models to reveal the relationship between the aerodynamic forces and crosswind were constructed to serve as inputs of the multi-body dynamics to analyze the handling stability under crosswind. The performance of crosswind stability is evaluated by the response of lateral acceleration, yaw rate and the lateral displacement. The lateral acceleration and yaw rate were decreased by a maximum of 14.6% and 16.5% compared to the truck without the deflector, which showed that the crosswind aerodynamics and stability were obviously improved.

Study of Self-Propelled Pufferfish Driven by Multiple Fins: A Comparison Between Rigid and Deformable Fins

2017 ◽  
Author(s):  
Ruoxin Li ◽  
Qing Xiao ◽  
Lijun Li ◽  
Hao Liu
Keyword(s):  
Underlying Mechanism ◽  
Operating Conditions ◽  
The Self ◽  
Fish Swimming ◽  
Propulsion Efficiency ◽  
Live Fish ◽  
Body Dynamics ◽  
Computational Fluid Dynamics Cfd ◽  
Multi Body ◽  
Better Than

In this work, we numerically studied the steady swimming of a pufferfish driven by the undulating motion of its dorsal, anal and caudal fins. The simulations are based on experimentally measured kinematics. To model the self-propelled fish swimming, a Computational Fluid Dynamics (CFD) tool was coupled with a Multi-Body-Dynamics (MBD) technique. It is widely accepted that deformable/flexible or undulating fins are better than rigid fins in terms of propulsion efficiency. To elucidate the underlying mechanism, we established an undulating fins model based on the kinematics of live fish, and conducted a simulation under the same operating conditions as rigid fins. The results presented here agree with this view by showing that the contribution of undulating fins to propulsion efficiency is significantly larger than that of rigid fins.

Test Results: Vehicle Responses to Simulated Drag Caused by Front Tire Tread Detachment — The Effect of Scrub Radius and Speed

2018 ◽  
Author(s):  
Mark W. Arndt ◽  
Stephen M. Arndt
Keyword(s):  
Lateral Displacement ◽  
Rear Wheel ◽  
Lateral Acceleration ◽  
Steering Wheel ◽  
Slip Angle ◽  
Yaw Rate ◽  
Wheel Drive ◽  
Steady State Responses ◽  
Four Wheel Drive ◽  
Left Front

The effects of reduced kingpin offset distance at the ground (scrub radius) and speed were evaluated under controlled test conditions simulating front tire tread detachment drag. While driving in a straight line at target speeds of 50, 60, or 70 mph with the steering wheel locked, the drag of a tire tread detachment was simulated by applying the left front brake with a pneumatic actuator. The test vehicle was a 2001 dual rear wheel four-wheel-drive Ford F350 pickup truck with an 11,500 lb. GVWR. The scrub radius was tested at the OEM distance of 125 mm (Δ = 0) and at reduced distances of 49 mm (Δ = −76) and 11 mm (Δ = −114). The average steady state responses at 70 mph with the OEM scrub radius were: steering torque = −24.5 in-lb; slip angle = −3.8 deg; lateral acceleration = −0.47 g; yaw rate = −8.9 deg/sec; lateral displacement after 0.75 seconds = 3.1 ft and lateral displacement after 1.5 seconds = 13.1 ft. At the OEM scrub radius, responses that increased linearly with speed included: slip angle (R2 = 0.84); lateral acceleration (R2 = 0.93); yaw rate (R2 = 0.73) and lateral displacement (R2 = 0.59 and R2 = 0.87, respectively). At the OEM scrub radius, steer torque decreased linearly with speed (R2 = 0.76) and longitudinal acceleration had no linear relationship with speed (R2 = 0.09). At 60 mph and 70 mph for both scrub radius reductions, statistically significant decreases (CI ≥ 95%) occurred in average responses of steer torque, slip angle, lateral acceleration, yaw rate, and lateral displacement. At 50 mph, reducing the OEM scrub radius to 11 mm resulted in statistically significant decreases (CI ≥ 95%) in average responses of steer torque, lateral acceleration, yaw rate and lateral displacement. At 50 mph the average slip angle response decreased (CI = 87%) when the OEM scrub radius was reduced to 11 mm.

Simulation Research on Braking Safety Properties of Aircraft Traction System

2009 ◽  
Vol 419-420 ◽  
pp. 705-708 ◽  
Author(s):  
Neng Jian Wang ◽  
Li Jie Zhou ◽  
Qiang Song ◽  
De Fu Zhang
Keyword(s):  
Critical Conditions ◽  
Safety Properties ◽  
Simulation Research ◽  
Straight Line ◽  
Body Dynamics ◽  
Braking Torque ◽  
Traction System ◽  
Multi Body ◽  
Dynamics Models ◽  
The Relationship

The jack-knifing tendency of aircraft traction system during braking was discussed and analyzed using multi-body dynamics models that consist of aircraft-towing tractor, aircraft draw link and aircraft. The braking critical conditions of the aircraft traction system for straight-line braking and turning braking were discussed and analyzed respectively. In the case of straight-line braking, the effect of friction coefficient on the maximum braking torque is described. In the case of turning braking, the relationship between the maximum baking torque and relative angle is obtained.

The Multi-Body Dynamics Analysis and Experiment of Long Distance Steel Belt Transmission

2014 ◽  
Vol 971-973 ◽  
pp. 816-822
Author(s):  
Zhi Ping Chen ◽  
En Dao Xu ◽  
Zhen Jie Zhang ◽  
Shuai Mou ◽  
Shi Feng Yue ◽  
...  
Keyword(s):  
Stress And Strain ◽  
Body System ◽  
Long Distance ◽  
Sliding Motion ◽  
Body Dynamics ◽  
Coupling Dynamics ◽  
Belt Transmission ◽  
Multi Body ◽  
The Relationship ◽  
Element Theory

This paper establishes the dynamic model of the long distance steel belt friction transmission with multi-body system rigid-flexible coupling dynamics theory, employs the boundary element theory to research the setting of the boundary conditions, and then improve the reliability of the simulation and calculation. This paper simulates and analyzes the relationship between pre-load and load,as well as that between stress and strain,so that gets the better transmission accuracy. Starting with experiment, this paper researches on the tension characteristics, running deviation and transmission accuracy of the long distance steel belt. by comparing the result of the simulation, this paper obtains the fitting function of the pre-load of the long distance steel belt and proves it have high transmission accuracy under certain condition which has proper pre-load and load.The experiment shows that the home-made precision friction transmission testbed has the ability of precision transmission. Taking advantage of the friction transmission features of steel belt, it can solve the low transmission accuracy of conventional belt transmission which results from small Elastic modulus and big elasticity sliding motion, and fulfills the long distance friction transmission on the engineering, the deviation can be smaller than 0.5%.

Handling Stability Performance Simulation and Analysis of Three Different Vehicle Models

2010 ◽  
Vol 29-32 ◽  
pp. 750-755
Author(s):  
Shu Feng Wang ◽  
Hua Shi Li ◽  
Cui Hua He
Keyword(s):  
Lateral Acceleration ◽  
Dynamics Model ◽  
Vehicle Model ◽  
Performance Simulation ◽  
Vehicle Handling ◽  
Stability Performance ◽  
Body Dynamics ◽  
Nonlinear Vehicle Model ◽  
Simulation Results ◽  
Multi Body

In order to obtain accurate vehicle handling stability performance, 2 DOF nonlinear vehicle model and multi-body dynamics vehicle model are established. Selecting the same vehicle parameters, step steering angle input simulations of three vehicle model (include 2DOF linear vehicle model) are carried out under the same driving conditions, simulation results are analyzed and compared. The simulation results show that 2DOF linear model can characterize the steering states of vehicle when vehicle lateral acceleration is small, but when vehicle lateral acceleration is big, Nonlinear vehicle model and multi-body dynamics model is accurate.

scholarly journals Investigation of the dynamic characteristics of suspension parameters on a vehicle experiencing steering drift during braking

2005 ◽  
Vol 219 (12) ◽  
pp. 1429-1441 ◽  
Author(s):  
N Mirza ◽  
K Hussain ◽  
A J Day ◽  
J Klaps
Keyword(s):  
Dynamic Characteristics ◽  
Simulation Study ◽  
Simulation Modelling ◽  
Lateral Acceleration ◽  
Dynamics Analysis ◽  
Suspension Parameters ◽  
Straight Line ◽  
Body Dynamics ◽  
Suspension Geometry ◽  
Multi Body

This paper presents a simulation study into the characteristics of a vehicle experiencing steering drift under straight line braking. Simulation modelling has been performed using a multi-body dynamics analysis based on a model of an actual vehicle. Front and rear suspension parameters have been modelled as rigid links joined with flexible bushes so as to assess their effect on a vehicle while braking. Suspension geometry and alignment settings, which define characteristic responses such as lateral acceleration, yaw velocity, toe, and caster angles of a vehicle in a transient manoeuvre, are primary to a vehicle's directional stability. Any symmetric inconsistencies in these settings will potentially affect a vehicle's performance. The findings from this research have increased the understanding of the causes of steering drift during braking conditions.

scholarly journals Rollover threshold investigation of a heavy-duty vehicle during cornering based on multi-body dynamics

2018 ◽  
Vol 10 (7) ◽  
pp. 168781401878950
Author(s):  
Xiaotong Dong ◽  
Yi Jiang ◽  
Zhou Zhong ◽  
Wei Zeng
Keyword(s):  
Three Dimensional ◽  
Warning System ◽  
Lateral Acceleration ◽  
Transportation Safety ◽  
Heavy Duty ◽  
Transform Method ◽  
Heavy Duty Vehicle ◽  
Body Dynamics ◽  
Vehicle Test ◽  
Multi Body

The objective of this article is to investigate the rollover threshold of a heavy-duty vehicle during cornering. Based on the multi-body dynamics theory, a high-fidelity model is established, which takes account of the chassis flexibility, the suspension nonlinear characteristics, the tire handling model, and Ackermann steering strategy. Furthermore, by the inverse fast Fourier transform method, a three-dimensional stochastic road in space domain is employed in the model to improve the accuracy. A full-size heavy-duty vehicle test was carried out to validate the model. Based on the validated model, the rollover stability and rollover threshold of the heavy-duty vehicle during cornering are investigated. Lateral acceleration, yaw rate, roll angle, and vehicle torsional deflection in different cornering conditions are analyzed. The rollover threshold is summarized by the response surface methodology for the safe cornering purpose. The result shows the practical meaning of improving transportation safety of heavy-duty vehicles and also provides useful insights for developing the rollover warning system.

DYNAMICS MODELING AND SIMULATION OF A KIND OF WHEELED HUMANOID ROBOT BASED ON SCREW THEORY

2012 ◽  
Vol 09 (04) ◽  
pp. 1250029 ◽  
Author(s):  
JINGGUO WANG ◽  
YANGMIN LI
Keyword(s):  
Humanoid Robot ◽  
Screw Theory ◽  
Kinematics And Dynamics ◽  
Variation Principle ◽  
Dynamics Modeling ◽  
Modeling Methodology ◽  
Body Dynamics ◽  
Simulation Results ◽  
Multi Body ◽  
The Relationship

Based on the screw theory and Lie group notations, this paper presents a modeling method for a kind of wheeled humanoid robot whose upper human-like body is mounted on the top of a mobile platform with three wheels. By combining the reciprocal product of the twist and wrench with Jourdain variation principle, a general formulation method is proposed to model the whole system's dynamics that represents directly the relationship between the input and the resultant external and inertial wrench. Both the system kinematics and dynamics are derived carefully. The simulations are made to verify the proposed modeling methodology and the simulation results are also compared with the results obtained from the multi-body dynamics software.

Research on Crosswind Stability of FSAE Racing Car with Rear Wing at Different Attack Angles

2012 ◽  
Vol 152-154 ◽  
pp. 737-742 ◽  
Author(s):  
Jun Ni ◽  
Si Zhong Chen ◽  
Da Feng ◽  
Xu Jie Wang ◽  
Jia Xin Hao
Keyword(s):  
Virtual Prototyping ◽  
Aerodynamic Characteristics ◽  
Attack Angle ◽  
Feasible Method ◽  
Body Model ◽  
Rear Wing ◽  
Air Resistance ◽  
Crosswind Stability ◽  
Virtual Prototyping Technology ◽  
Multi Body

In order to analyze the performance of a certain FSAE racing car with rear wing at different attack angles by virtual prototyping technology. The multi-body model of a FSAE racing car which takes non-linear factors into consideration was built by applying ADAMS/Car. The correctness of the model is verified by comparison with the actual experiment result. By the simulation of the air resistance and lift characteristics of the rear wing, a feasible method to building the aerodynamic characteristics of the rear wing in multi-body model was proposed. Based on these, the crosswind stability of FSAE racing car with rear wing at different attack angles was analyzed, the result shows that the effect of crosswind is reduced with the increase of the attack angle of the rear wing.

scholarly journals Investigation of the influence of the dimensionality of the mathematical model of the ship's motion the result of predicting its controllability

2021 ◽  
pp. 26-34
Author(s):  
В.В. Багринцев ◽  
В.В. Макарова ◽  
Ю.П. Потехин
Keyword(s):  
Mathematical Model ◽  
Lateral Displacement ◽  
Hydrodynamic Characteristics ◽  
Yaw Rate ◽  
Spatial Movement ◽  
Different Dimensions ◽  
Heading Angle ◽  
Motion Parameters ◽  
The Mathematical Model ◽  
The Relationship

В работе рассматривается влияние размерности математической модели движения судна на параметры движения, характеризующие его управляемость, к которым относятся курсовой угол, угловая скорость рыскания, продольное и боковое смещение. Указанное влияние определяется путем имитационного моделирования движения судна посредством математической модели плоского движения в плоскости невозмущенной поверхности воды, модели бокового и пространственного движения. Тестовым маневром является полная циркуляция судна на тихой воде и волнении различной балльности. В качестве опорного результата принимается картина движения, доставляемая пространственной моделью, как наиболее отвечающая условиям реального плавания. В результате тестирования 6 судов различных классов установлено, что соотношение между результатами прогнозирования поворотливости посредством моделей различной размерности существенно зависит от гидродинамических характеристик объекта исследования. The paper considers the influence of the dimension of the mathematical model of the ship's motion on the motion parameters characterizing its controllability, which include the heading angle, angular yaw rate, longitudinal and lateral displacement. This influence is determined by simulating the movement of the vessel using a mathematical model of plane movement in the plane of the undisturbed water surface, a model of lateral and spatial movement. The test maneuver this is the full circulation of the vessel in smooth water and on the varying conditions wave. The picture of movement, delivered by the spatial model, is taken as a reference result, as the most measure up for the conditions of real swimming. As a result of testing 6 vessels of various classes, it was found that the relationship between the results of predicting turnability by means of models of different dimensions significantly depends on the hydrodynamic characteristics of the research object.

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