Multibody Investigation on the Passive Safety Performances of Seats in Railway Vehicles

2010 ◽  
Author(s):  
Francesco Caputo ◽  
Francesco Fidanza ◽  
Giuseppe Lamanna
Keyword(s):  
Experimental Data ◽  
Experimental Tests ◽  
Passive Safety ◽  
Medium Size ◽  
Railway Vehicle ◽  
Seat Belts ◽  
Test Device ◽  
Sled Test ◽  
Research Activities ◽  
Multi Body

The research activities described in this paper aim to identify the causes and the typologies of secondary impact injuries to passengers of a railway vehicle during a specific crash event, to understand the measure in which these injuries can be absorbed and to identify possible ways of reducing or eliminating them. The main investigated solution was to restrain passengers to their seats by considering the presence of seat belts. Biomechanical performances of passenger configurations with two-point and three-point seat belts were investigated and compared with those of unrestrained passengers. An anthropomorphic test device representative of medium size people was furnished and experimental tests were worked out in order to obtain effective data regarding the interaction of passengers with seats and seatbelts. By using these experimental data a multi-body numerical model of the sled test was calibrated and validated and restraining configuration performances, which could not be physically tested, were simulated.

A Multi-Body Modeling and Design of Experiment Investigation of a Motorcyclist Impact on Roadside Barriers at Upright and Sliding Configurations

2011 ◽  
Author(s):  
Rasoul Moradi ◽  
Hamid M. Lankarani
Keyword(s):  
Experimental Data ◽  
Design Of Experiment ◽  
Parametric Study ◽  
Reasonable Agreement ◽  
Crash Test ◽  
Test Device ◽  
Crash Injuries ◽  
Major Factors ◽  
Multi Body ◽  
Impact Angles

Roadside guard systems such as concrete and wire barriers and steel guard rails are mainly developed to protect occupants of the errant cars or trucks. Yet motorcycle riders are vulnerable to these barriers and guard systems, and impact on these barriers may result in major injuries. The objective of this study is to examine the major factors causing injuries in motorcycle-barriers accidents. A mathematical multi-body motorcycle model with a motorcycle anthropometric test device, MATD, is developed in the MADYMO 7.2 for this purpose. The motorcycle model as well as the motorcycle and rider model are validated using full-scale crash test data available in the literature. The simulations results are found to be in a reasonable agreement with the experimental data. A parametric study using the design of experiment (DOE) is then conducted to investigate the nature of crash injuries for various impact speeds, impact angles, different bike and rider positions to assess the rider kinematics and potential injuries. The results from this study can help in designing road barriers and guard systems in order to protect the motorcycle riders.

A New Dynamic Wettability-Alteration Model for Oil-Wet Cores During Surfactant-Solution Imbibition

SPE Journal ◽  
2013 ◽  
Vol 18 (05) ◽  
pp. 818-828 ◽  
Author(s):  
M. Hosein Kalaei ◽  
Don W. Green ◽  
G. Paul Willhite
Keyword(s):  
Experimental Data ◽  
Oil Recovery ◽  
History Matching ◽  
Mechanistic Model ◽  
Surfactant Solution ◽  
Experimental Tests ◽  
Quantitative Agreement ◽  
Wettability Alteration ◽  
Porous Rock ◽  
Surfactant Solutions

Summary Wettability modification of solid rocks with surfactants is an important process and has the potential to recover oil from reservoirs. When wettability is altered by use of surfactant solutions, capillary pressure, relative permeabilities, and residual oil saturations change wherever the porous rock is contacted by the surfactant. In this study, a mechanistic model is described in which wettability alteration is simulated by a new empirical correlation of the contact angle with surfactant concentration developed from experimental data. This model was tested against results from experimental tests in which oil was displaced from oil-wet cores by imbibition of surfactant solutions. Quantitative agreement between the simulation results of oil displacement and experimental data from the literature was obtained. Simulation of the imbibition of surfactant solution in laboratory-scale cores with the new model demonstrated that wettability alteration is a dynamic process, which plays a significant role in history matching and prediction of oil recovery from oil-wet porous media. In these simulations, the gravity force was the primary cause of the surfactant-solution invasion of the core that changed the rock wettability toward a less oil-wet state.

Hybrid Fatigue Analysis Method for Railway Carbody Structure

2008 ◽  
Vol 44-46 ◽  
pp. 733-738 ◽  
Author(s):  
Bing Rong Miao ◽  
Wei Hua Zhang ◽  
Shou Ne Xiao ◽  
Ding Chang Jin ◽  
Yong Xiang Zhao
Keyword(s):  
Fatigue Life ◽  
Fatigue Damage ◽  
Hybrid Method ◽  
Dynamic Stress ◽  
Stress Test ◽  
Fatigue Analysis ◽  
Railway Vehicle ◽  
Analysis Method ◽  
Structure Dynamic ◽  
Multi Body

Railway vehicle structure fatigue life consumption monitoring can be used to determine fatigue damage by directly or indirectly monitoring the loads placed on critical vehicle components susceptible to failure from fatigue damage. The sample locomotive carbody structure was used for this study. Firstly, the hybrid fatigue analysis method was used with Multi-Body System (MBS) simulation and Finite Element Method (FEM) for evaluating the carbody structure dynamic stress histories. Secondly, the standard fatigue time domain method was used in fatigue analysis software FE-FATIGUE and MATLAB WAFO (Wave Analysis for Fatigue and Oceanography) tools. And carbody structure fatigue life and fatigue damage were predicted. Finally, and carbody structure dynamic stress experimental data was taken from this locomotive running between Kunming-Weishe for this analysis. The data was used to validate the simulation results based on hybrid method. The analysis results show that the hybrid method prediction error is approximately 30.7%. It also illustrates that the fatigue life and durability of the locomotive can be predicted with this hybrid method. The results of this study can be modified to be representative of the railway vehicle dynamic stress test.

Rounded Fin Edge and Step Position Effects on Discharge Coefficient in Rotating Labyrinth Seals

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Andrea Rapisarda ◽  
Alessio Desando ◽  
Elena Campagnoli ◽  
Roberto Taurino
Keyword(s):  
Experimental Data ◽  
Numerical Simulations ◽  
Leading Edge ◽  
Experimental Tests ◽  
Velocity Profiles ◽  
Pollutant Emission ◽  
Leakage Flow ◽  
Labyrinth Seals ◽  
Position Effects ◽  
Impact Reduction

The design of modern aircrafts propulsion systems is strongly influenced by the important objective of environmental impact reduction. Through a great number of researches carried out in the last decades, significant improvements have been obtained in terms of lower fuel consumption and pollutant emission. Experimental tests are a necessary step to achieve new solutions that are more efficient than the current designs, even if during the preliminary design phase, a valid alternative to expensive experimental tests is the implementation of numerical models. The processing power of modern computers allows indeed the simulation of more complex and detailed phenomena than the past years. The present work focuses on the implementation of a numerical model for rotating stepped labyrinth seals installed in low-pressure turbines. These components are widely employed in sealing turbomachinery to reduce the leakage flow between rotating components. The numerical simulations were performed by using computational fluid dynamics (CFD) methodology, focusing on the leakage performances at different rotating speeds and inlet preswirl ratios. Investigations on velocity profiles into seal cavities were also carried out. To begin with, a smooth labyrinth seal model was validated by using the experimental data found in the literature. The numerical simulations were extended to the honeycomb labyrinth seals, with the validation performed on the velocity profiles. Then, the effects of two geometrical parameters, the rounded fin tip leading edge, and the step position were numerically investigated for both smooth and honeycomb labyrinth seals. The obtained results are generally in good agreement with the experimental data. The main effect found when the fin tip leading edge was rounded was a large increase in leakage flow, while the step position contribution to the flow path behavior is nonmonotone.

Motorcycle Analytical Modeling Including Tire–Wheel Nonuniformities for Ride Comfort Analysis

2017 ◽  
Vol 45 (2) ◽  
pp. 101-120 ◽  
Author(s):  
Matheus de B. Vallim ◽  
José M. C. Dos Santos ◽  
Argemiro L. A. Costa
Keyword(s):  
Degrees Of Freedom ◽  
Analytical Modeling ◽  
Ride Comfort ◽  
Experimental Tests ◽  
Rotational Frequency ◽  
Analytical Models ◽  
Vertical Force ◽  
Lumped Mass ◽  
Multi Body ◽  
4 Degrees Of Freedom

ABSTRACT The transmission of vibrations in motorcycles and their perception by the passengers are fundamental in comfort analysis. Tire nonuniformities can generate self-excitations at the rotational frequency of the wheel and contribute to the ride vibration environment. In this work a multi-body motorcycle model is built to evaluate the ride comfort with respect to tire nonuniformities. The aim is to obtain a multi–degrees-of-freedom dynamic model that includes both the contributions of the motorcycle and tire–wheel assembly structures. This representation allows the tire nonuniformities to predict the vertical force variations on the motorcycle and can be used through a root mean square acceleration evaluation for ride comfort analysis. The motorcycle model proposed is a 10-degrees-of-freedom system, where each tire–wheel is a 4-degrees-of-freedom model. The tire–wheel assemblies include two types of nonuniformities: lumped mass imbalance and radial run-out. Simulations of analytical models are compared with experimental tests.

A Comparative Experiment on the Bond-Slip of Reinforced Concrete

2012 ◽  
Vol 226-228 ◽  
pp. 1795-1799
Author(s):  
Chuan Guo Cai ◽  
Guo Liang Chen
Keyword(s):  
Experimental Data ◽  
Reinforced Concrete ◽  
Concrete Columns ◽  
Comparative Experiment ◽  
Test Device ◽  
Static Test ◽  
Bond Slip ◽  
Repeated Load ◽  
S Curve ◽  
The One

A new test device, which can be used for measuring the stain and the displacement on the adhesive interface while the slip occurs within the reinforced concrete, is proposed and designed. With that, a comparative experiment is carried out on a group of the reinforced concrete columns bearing alternating load to obtain the τ-s curve. The hysteretic curves of these specimens are recorded timely. The result from the one-way repeated load is similar with several well-known expressions which are commonly cited at home and abroad. That from the low cycle load reveals some certain characteristic of the alternating slip, which there isn't in the static test. The experimental data could make contribution for the numerical simulation on bridge and seismic building.

Finite Element Dynamic Analysis of a Railway Seat Under Longitudinal Impact Condition

2011 ◽  
Author(s):  
Francesco Caputo ◽  
Giuseppe Lamanna ◽  
Alessandro Soprano
Keyword(s):  
Finite Element ◽  
Structural Integrity ◽  
Seat Belt ◽  
Element Model ◽  
Railway Vehicle ◽  
Longitudinal Impact ◽  
Structural Behaviour ◽  
Structural Dynamic ◽  
Sled Test ◽  
Seat Frame

For a railway vehicle, the structural integrity of the seat frame and of its connection to that of the coach is a very important aspect of the design phase addressed to the improvement of the passive safety performances, at most because the analysis of the accidents occurred in recent years shows that secondary impacts against vehicle interiors remain one of the main causes of injury. All regulations which apply to this task start from the assumption that whatever happens to the vehicle the seat must remain connected to the vehicle frame, as well as the different parts to each other. Numerical evaluations are obviously necessary to match with this design requirement; it would be desirable to apply multi-body (MB) codes to this task, as they are really fast, but unfortunately they can’t provide detailed results for what concerns the structural behaviour of the involved seat and vehicle components. For this reason, in the present work a full finite element model of a sled-test, including a FE dummy, has been developed, analysed and validated by comparison with the available experimental results; it has been also showed how this kind of numerical simulation is suited and necessary to evaluate the structural behaviour of the structural components of the seat frame. In the context of the presented study the MADYMO® code has been adopted to perform the preliminary MB analyses necessary to calibrate and evaluate the relevant parameters of dummy-seat contact surfaces and of seat-belt stiffness, while LS DYNA® code has been used for the structural dynamic FE analyses.

Experimental tests of an improved 5D Kaluza-Klein theory

2020 ◽  
Vol 35 (02n03) ◽  
pp. 2040027
Author(s):  
Jean Paul Mbelek
Keyword(s):  
Experimental Data ◽  
Scalar Field ◽  
Experimental Tests ◽  
Torsion Pendulum ◽  
Klein Theory ◽  
Kaluza Klein

We recall the motivation for an external scalar field, [Formula: see text], and show how it helps to improve the 5D Kaluza-Klein theory. Various applications of the theory that fit observational or experimental data in the laboratory as well as in the cosmological or astrophysical contexts are mentioned. Special attention is given to the last version of the experiment showing evidence of a torque on a torsion pendulum as predicted by the theory. New arguments that motivate extradimensions are put forward.

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