The Impact of Suspension Stiffness Parameters on the Curve through Performance of Straddle Type Monorail Vehicle Based on Sensitivity Analysis

2013 ◽  
Vol 470 ◽  
pp. 563-566
Author(s):  
Zi Xue Du ◽  
Zhi Hua Liang ◽  
Xiao Xia Wen
Keyword(s):  
Sensitivity Analysis ◽  
Vehicle Body ◽  
Vertical Force ◽  
Wear Performance ◽  
Evaluation Indexes ◽  
Body Roll ◽  
Overturning Stability ◽  
Suspension Stiffness ◽  
Tire Forces ◽  
The Impact

The curve through performance of straddle type monorail vehicle include performance-oriented, preventing derailment stability, preventing vehicle overturning stability, tire wear performance, which are evaluated by oriented torque, the minimum vertical force of horizontal wheels, vehicle body roll angle, overturning coefficient, the sum of tire forces scalar. With the virtual simulation model in ADAMS, this paper analyzes the impact of the monorail vehicle suspension stiffness parameters on the evaluation indexes by sensitivity analysis.

Active Torsion Bar Body Roll Minimization System: Design and Testing

2003 ◽  
Author(s):  
David Cimba ◽  
Kyle Gilbert ◽  
John Wagner
Keyword(s):  
Cost Effective ◽  
Vehicle Body ◽  
Design Parameters ◽  
Test Environment ◽  
Component Design ◽  
Body Roll ◽  
And Performance ◽  
Emergency Scenarios ◽  
The Impact ◽  
Torsion Bar

Sport utility and light-duty commercial vehicles exhibit a higher propensity for rollover during aggressive driving maneuvers, emergency scenarios, and degraded environmental conditions. A variety of strategies have been proposed to reduce vehicle body roll including active suspensions, comprehensive yaw stability systems, and active torsion bars. The active torsion bar systems have recently gained popularity due to their cost effective design and adaptability to existing chassis systems. However, the development of new control algorithms, design of subsystem components, and the evaluation of parameter sensitivity via testing a full scale vehicle is not always practical due to cost and safety concerns. Thus, a modular simulation tool and bench top testing environment is required to facilitate design and performance studies. In this paper, a series of mathematical models will be introduced to describe the vehicle dynamics and the roll prevention system. Representative numerical results are discussed to investigate a vehicle’s transient response with and without an active torsion bar system, as well as the impact of torsion bar and hydraulic component design parameters. Finally, a hardware in-the-loop test environment will be presented.

The Effects of Tire Properties and Their Interaction with the Ground and Suspension on Vehicle Dynamic Behavior — A Finite Element Approach

1999 ◽  
Vol 27 (4) ◽  
pp. 227-249 ◽  
Author(s):  
Y. Zhang ◽  
C. Hazard
Keyword(s):  
Finite Element ◽  
Dynamic Behavior ◽  
Practical Method ◽  
Suspension System ◽  
Vehicle Body ◽  
Vehicle Dynamic ◽  
Analysis Method ◽  
Element Analysis ◽  
Body Roll ◽  
The Impact

Abstract The effects of tire properties and their interaction with the ground and the suspension system on vehicle dynamic behavior was studied using a newly developed finite element analysis method. This analysis method used the explicit nonlinear dynamic code LS-DYNA as a solver and contained finite element models for both the vehicle body structure and subsystems like chassis/suspension. The case presented in this paper is curb impact. Different tire properties such as tire/wheel assembly mass, tire stiffness, tire inflation pressure, tire size, etc., as well as different curb heights, were used with the same vehicle body and suspension system. Simulation results of the impact forces, wheel center jumps, and vehicle body roll/pitch angles at impact are compared for different parameters of the tires and the curb. The analyses presented in this paper provided an accurate and practical method for tire and vehicle dynamics analysis.

scholarly journals The influence of vehicle body roll angle on the motion stability and maneuverability of the vehicle

2017 ◽  
Vol 168 (1) ◽  
pp. 133-139
Author(s):  
Krzysztof PARCZEWSKI ◽  
Henryk WNĘK
Keyword(s):  
Dynamic Change ◽  
Steady Motion ◽  
Roll Angle ◽  
Vehicle Body ◽  
Sideslip Angle ◽  
Lateral Forces ◽  
Camber Angle ◽  
Body Roll ◽  
Vehicle Motion ◽  
The Impact

The article discusses the impact of design solutions of vehicle suspensions into angles of body roll. It was shown which type of suspensions is better from this point of view. There were examined the dependence of the suspensions parameters on the vehicle body roll angle. The influence of camber angle on the force transmitted to the tire contact with the road surface was analysed. The lateral forces were measured on the test stand. There was tested dependency of lateral forces from the sideslip angle for different angles of camber. Was analysed change of lateral forces generated by camber angle on the vehicle which was made on a scale ~ 1:5 during tests carried out on the testing track. For this purpose, two tests have been selected: first one allowing the measurement in steady motion conditions, the second one with dynamic change of direction of vehicle motion. The graphs show the effect of camber angles on the controllability and stability of the vehicle motion.

scholarly journals Are EDR Devices Undoubtedly Helpful in the Reconstruction of a Road Traffic Accident?

Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6940
Author(s):  
Marek Guzek ◽  
Zbigniew Lozia
Keyword(s):  
Motor Vehicle ◽  
Road Traffic ◽  
Simulation Models ◽  
Simulation Method ◽  
Vehicle Body ◽  
Body Roll ◽  
Calculation Results ◽  
Vehicle Motion ◽  
Vehicle Trajectory ◽  
The Impact

All over the world, the vehicles introduced now into the market are usually provided with EDRs (Event Data Recorders), intended to measure and record the parameters that characterise the vehicle motion in the pre-, during-, and post-accident phases. The EDRs are to facilitate the description and reconstruction of possible road accidents. They are patterned on aircraft “black boxes” (flight recorders). Many of them have simplified design, disregarding three (of six) vector components that describe the motion of the vehicle body solid. In the paper presented, the authors used simulation models built by themselves to represent motor vehicle dynamics and the reconstruction of vehicle trajectory and velocities based on records obtained from two EDR types: “aircraft” one (EDR1) and “simplified” one (EDR2). Using a simulation method, they examined the impact of the said simplifications mentioned above on the quality of reconstruction of vehicle motion for four typical manoeuvres in road traffic. The calculation results obtained for input data adopted to rep-resent a medium-class passenger car have shown that the simplifications may cause considerable reconstruction errors. This particularly applies to the manoeuvres where significant changes took place in the roll and pitch angles of the vehicle body solid (to which the EDR was fixed) or where the changes were characterised by absence of symmetry in the parameters that describe the manoeuvre and by the constant sign of the vehicle body roll angles.

Studies on Related ms Magnitude Rate Models in Triangular Wave Unloading Section of Calcium Medium-Fine Sandstone

2010 ◽  
Vol 152-153 ◽  
pp. 164-170
Author(s):  
Jie Liu ◽  
Jian Lin Li ◽  
Ying Xia Li ◽  
Shan Shan Yang ◽  
Ji Fang Zhou ◽  
...  
Keyword(s):  
Mechanical Response ◽  
Strain Curve ◽  
Experimental System ◽  
Constant Term ◽  
Lag Time ◽  
Vertical Force ◽  
Time Segment ◽  
Triangular Wave ◽  
Apparent Modulus ◽  
The Impact

Specific to the improvement in the present research of mechanical response under cyclic loading, this paper, taking the calcareous middle- coarse sandstone as the research subject and the RMT-150C experimental system in which data is recoded by ms magnitude as the platform, develops several related models concerning the unloading rate of triangle waves. The unloading process is divided into lag time segment and non-lag time segment, with criterions and related parameters provided as well. The term apparent elastic modulus is defined. The test data analysis shows that there exist a linear relationship between the apparent modulus and instant vertical force before load damage in non-lag time segment. On the preceding basis, a rate-dependent model of triangular wave un-installation section in non-lag time segment is established. Due to the inability of the loading equipment to accurately input the triangle wave, the average loading rate is amended and a constant term is added into it. The model is proved to be reliable, as the predicted value of the deformation rate and the stress strain curve coincides with measured value. At the same time, the impact of the lag time is pointed out quantitatively and a predication model of lag time segment is set up.

scholarly journals Robust Inferences from a Before-and-After Study with Multiple Unaffected Control Groups

2013 ◽  
Vol 1 (2) ◽  
pp. 209-234 ◽  
Author(s):  
Pengyuan Wang ◽  
Mikhail Traskin ◽  
Dylan S. Small
Keyword(s):  
Sensitivity Analysis ◽  
Control Groups ◽  
Two Stage ◽  
Time Effects ◽  
Unaffected Control ◽  
Group Time ◽  
Before And After ◽  
Group Variation ◽  
The Impact ◽  
Before And After Study

AbstractThe before-and-after study with multiple unaffected control groups is widely applied to study treatment effects. The current methods usually assume that the control groups’ differences between the before and after periods, i.e. the group time effects, follow a normal distribution. However, there is usually no strong a priori evidence for the normality assumption, and there are not enough control groups to check the assumption. We propose to use a flexible skew-t distribution family to model group time effects, and consider a range of plausible skew-t distributions. Based on the skew-t distribution assumption, we propose a robust-t method to guarantee nominal significance level under a wide range of skew-t distributions, and hence make the inference robust to misspecification of the distribution of group time effects. We also propose a two-stage approach, which has lower power compared to the robust-t method, but provides an opportunity to conduct sensitivity analysis. Hence, the overall method of analysis is to use the robust-t method to test for the overall hypothesized range of shapes of group variation; if the test fails to reject, use the two-stage method to conduct a sensitivity analysis to see if there is a subset of group variation parameters for which we can be confident that there is a treatment effect. We apply the proposed methods to two datasets. One dataset is from the Current Population Survey (CPS) to study the impact of the Mariel Boatlift on Miami unemployment rates between 1979 and 1982.The other dataset contains the student enrollment and grade repeating data in West Germany in the 1960s with which we study the impact of the short school year in 1966–1967 on grade repeating rates.

scholarly journals A Model for the Thermal Behaviour of an Offshore Cable Installed in a J-Tube

Proceedings ◽  
2020 ◽  
Vol 58 (1) ◽  
pp. 31
Author(s):  
Jeremy Arancio ◽  
Ahmed Ould El Moctar ◽  
Minh Nguyen Tuan ◽  
Faradj Tayat ◽  
Jean-Philippe Roques
Keyword(s):  
Sensitivity Analysis ◽  
Numerical Model ◽  
Thermal Behaviour ◽  
Energy Production ◽  
Power Transmission ◽  
Temperature Fields ◽  
Sobol Indices ◽  
Lumped Element ◽  
Thermal Phenomena ◽  
The Impact

In the race for energy production, supplier companies are concerned by the thermal rating of offshore cables installed in a J-tube, not covered by IEC 60287 standards, and are now looking for solutions to optimize this type of system. This paper presents a numerical model capable of calculating temperature fields of a power transmission cable installed in a J-tube, based on the lumped element method. This model is validated against the existing literature. A sensitivity analysis performed using Sobol indices is then presented in order to understand the impact of the different parameters involved in the heating of the cable. This analysis provides an understanding of the thermal phenomena in the J-tube and paves the way for potential technical and economic solutions to increase the ampacity of offshore cables installed in a J-tube.

scholarly journals Innovative concepts for the usage of veneer-based hybrid materials in vehicle structures

2021 ◽  
pp. 146442072199839
Author(s):  
DB Heyner ◽  
G Piazza ◽  
E Beeh ◽  
G Seidel ◽  
HE Friedrich ◽  
...  
Keyword(s):  
Steel Strip ◽  
High Energy ◽  
The Body ◽  
Vehicle Body ◽  
Material System ◽  
Laminated Veneer Lumber ◽  
Hybrid Beam ◽  
Bending Load ◽  
The Impact ◽  
Very High

A promising approach for the development of sustainable and resource-saving alternatives to conventional material solutions in vehicle structures is the use of renewable raw materials. One group of materials that has particular potential for this application is wood. The specific material properties of wood in the longitudinal fiber direction are comparable to typical construction materials such as steel or aluminum. Due to its comparatively low density, there is a very high lightweight construction potential especially for bending load cases. Structural components of the vehicle body are exposed to very high mechanical loads in the case of crash impact. Depending on the component under consideration, energy has to be absorbed and the structural integrity of the body has to be ensured in order to protect the occupants. The use of natural materials such as wood poses particular challenges for such applications. The material characteristics of wood are dispersed, and depend on environmental factors such as humidity. The aim of the following considerations was to develop a material system to ensure the functional reliability of the component. The test boundary conditions for validation also play a key role in this context. The potential of wood–steel hybrid design based on laminated veneer lumber and steel was investigated for use in a component subjected to crash loads such as the door impact beam. The chosen solution involves a separation of functions. A laminated veneer lumber-based beam was hybridized with a steel strip on the tension side. The steel strip was designed to compensate the comparatively low elongation at fracture of the wood and to ensure the integrity of the beam. The wooden component was designed for high energy absorption due to delamination and controlled failure during the impact, while maintaining the surface moment of inertia, i.e. the bending stiffness of the entire component. This approach was chosen to ensure the functional safety of the component, avoid sudden component failure and utilize the high potential of both materials. The tests carried out provided initial functional proof of the chosen solution. The hybridization achieved significantly higher deformations without sudden failure of the beam. In addition, bending capabilities were increased significantly compared to a beam without hybridization. In comparison with a state-of-the-art steel beam, the hybrid beam was not able to achieve the maximum deformation and the target weight of the hybrid beam. Further optimization of the hybrid beam is therefore necessary.

scholarly journals Addition of Flucytosine to Fluconazole for the Treatment of Cryptococcal Meningitis in Africa: A Multicountry Cost-effectiveness Analysis

2019 ◽  
Vol 70 (1) ◽  
pp. 26-29 ◽  
Author(s):  
Tinevimbo Shiri ◽  
Angela Loyse ◽  
Lawrence Mwenge ◽  
Tao Chen ◽  
Shabir Lakhi ◽  
...  
Keyword(s):  
Sensitivity Analysis ◽  
Cost Effectiveness ◽  
Cryptococcal Meningitis ◽  
Cost Effective ◽  
Immunodeficiency Virus ◽  
The Mean ◽  
The Cost ◽  
The Impact ◽  
Costing Analysis ◽  
Very High

Abstract Background Mortality from cryptococcal meningitis remains very high in Africa. In the Advancing Cryptococcal Meningitis Treatment for Africa (ACTA) trial, 2 weeks of fluconazole (FLU) plus flucytosine (5FC) was as effective and less costly than 2 weeks of amphotericin-based regimens. However, many African settings treat with FLU monotherapy, and the cost-effectiveness of adding 5FC to FLU is uncertain. Methods The effectiveness and costs of FLU+5FC were taken from ACTA, which included a costing analysis at the Zambian site. The effectiveness of FLU was derived from cohorts of consecutively enrolled patients, managed in respects other than drug therapy, as were participants in ACTA. FLU costs were derived from costs of FLU+5FC in ACTA, by subtracting 5FC drug and monitoring costs. The cost-effectiveness of FLU+5FC vs FLU alone was measured as the incremental cost-effectiveness ratio (ICER). A probabilistic sensitivity analysis assessed uncertainties and a bivariate deterministic sensitivity analysis examined the impact of varying mortality and 5FC drug costs on the ICER. Results The mean costs per patient were US $847 (95% confidence interval [CI] $776–927) for FLU+5FC, and US $628 (95% CI $557–709) for FLU. The 10-week mortality rate was 35.1% (95% CI 28.9–41.7%) with FLU+5FC and 53.8% (95% CI 43.1–64.1%) with FLU. At the current 5FC price of US $1.30 per 500 mg tablet, the ICER of 5FC+FLU versus FLU alone was US $65 (95% CI $28–208) per life-year saved. Reducing the 5FC cost to between US $0.80 and US $0.40 per 500 mg resulted in an ICER between US $44 and US $28 per life-year saved. Conclusions The addition of 5FC to FLU is cost-effective for cryptococcal meningitis treatment in Africa and, if made available widely, could substantially reduce mortality rates among human immunodeficiency virus–infected persons in Africa.

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