Design, Analysis and Test of Multi-Stage Crashworthiness Energy Absorbing Device for Railway Vehicles

2019 ◽  
Author(s):  
Haifeng Hong ◽  
Hongtao Liu ◽  
Ziwen Fang ◽  
Kefei Wang ◽  
Jianran Wang ◽  
...  
Keyword(s):  
Railway Vehicle ◽  
Test Results ◽  
Railway Vehicles ◽  
Multi Stage ◽  
Element Simulation ◽  
Sufficient Energy ◽  
Stage 4 ◽  
Third Stage ◽  
Energy Absorbing ◽  
Stage 1

Abstract An anti-collision and energy absorbing device is generally placed at the front end of railway vehicles to provide controlled collapse and sufficient energy absorbing capacity. In the conventional way, the energy absorbing device is usually designed as an integrated part of the carbody that can’t be easily replaced nor maintained after crash. To increase the maintainability and energy absorbing capacity of the energy absorbing device, a Multi-stage Crashworthiness Energy Absorbing Device has been developed, in which the first-stage and the second-stage energy absorbing units can be replaced or repaired under the collision that is not severe enough to initiate the third-stage energy absorbing unit. The Crashworthiness Energy Management (CEM) has four stages: coupler energy absorbing components (stage 1), honeycomb in the sliding center anti-climber (stage 2), metal peeling tubes mounted at the back of the fixed anti-climber (stage 3) and the structural components in the cab area (stage 4). By comparing the simulation results and test results, it is concluded that the finite element simulation model can provide dependable and accurate prediction for collision behaviors. Based on the design, simulation and test data, a safe, reliable and maintainable Multi-stage Crashworthiness Energy Absorbing Device has been verified and validated, which can provide valuable reference for researchers and engineers in the crashworthiness and railway vehicle industry.

Deformation and Energy Absorption of Steel Square Tubes With Optimized Shape Design

2019 ◽  
Author(s):  
Xiaofang Liu ◽  
Ziwen Fang ◽  
Haifeng Hong ◽  
Jianran Wang ◽  
Yanwen Liu ◽  
...  
Keyword(s):  
Impact Force ◽  
Longitudinal Direction ◽  
Axial Direction ◽  
Shape Design ◽  
Test Results ◽  
Element Analysis ◽  
Railway Vehicles ◽  
Side Walls ◽  
Energy Absorbers ◽  
Energy Absorbing

Abstract Square crush tubes have been widely used as impact energy absorbers in automotive and railway vehicles. In this paper, a square tube with vertical plates and dents has been designed to increase the controllability and stability of crash performance. Vertical plates are welded perpendicularly to the side walls of the tube, which increase the transverse stiffness and ensure the tube crashes in longitudinal direction under impact not in ideal axial direction. Dents have been put on the side walls near the front end of the tube to ensure the collapse always start from the front and progress gradually to the end. To validate the design, finite element analysis (FEA) and various experiments has been conducted and evaluated. Firstly, the numerical simulations were carried out using the software LS-DYNA. Then, four specimens were manufactured and tested. The crash velocity, tube deformation and impact force showed great agreement between the simulations and test results. The number of tubes, tube wall thickness, cross-section, trigger plates and dents arrangement can be adjusted to meet the requirements of different applications. In one application, the energy absorbing device with four crush tubes provided progressive controlled collapse with energy absorbing capacity of 1.22MJ and impact force less than 4450kN. This robust crush tube design has been successfully applied in multiple railway vehicles and also has the potential to be applied in other industries such as automotive vehicles.

Design and Optimization of Front-End Structure With Integrated Energy Absorption for Railway Vehicles

2020 ◽  
Author(s):  
Xiaofang Liu ◽  
Jianran Wang ◽  
Yanwen Liu ◽  
Ziwen Fang ◽  
Yanping Zhang ◽  
...  
Keyword(s):  
Impact Force ◽  
Critical Role ◽  
Iteration Process ◽  
Railway Vehicle ◽  
Test Results ◽  
Element Analysis ◽  
Design And Optimization ◽  
Front End ◽  
The Finite Element Analysis ◽  
Energy Absorbing

Abstract As the main energy absorbing area of a railway vehicle, the front-end structure is critical to reduce the collapse of the passenger area and increase the safety of the vehicle in case of collision. In this paper, a front-end structure with integrated energy absorbing is introduced in detail as well as the iteration process. The front-end structure is mainly composed of anti-climber, collision posts, corner posts and four kinds of crush elements including center crush elements, side crush elements, interior crush elements and head girders. The shape, dimension, position, connection and material of those components are optimized multiple times based on the finite element analysis results of various load cases. The finalized structure can provide progressive controlled collapse with energy absorbing capacity of 1.22MJ and impact force less than 4450kN. At the same time, it is capable to withstand a static longitudinal load of 1224kN and vertical load of 334kN. To validate the design and analysis, the front-end structure is manufactured and tested under impact. The crash velocity, deformation and impact force show great agreement between the simulations and test results. From the design and optimization of this front end structure, it is concluded that placing the crush elements behind the collision post is beneficial for static strength design, the energy absorbing capability can be largely increased without taking additional space by using interior crush element and the geometry of the head girders plays an critical role in balancing the force distribution and providing stable crush performance.

PENINGKATAN INFORMASI TERKAIT PENDAFTARAN NPWP MELALUI SOSIALISASI PENDAFTARAN NPWP BAGI PRIBADI DAN PEMILIK UMKM DI KELURAHAN SENDANGGUWO, KECAMATAN TEMBALANG, KOTA SEMARANG

2020 ◽  
Vol 3 (2) ◽  
Author(s):  
Deddy Sulestiyono ◽  
Ropinov Saputro ◽  
Dian Anggraeni ◽  
Ika Pratiwi
Keyword(s):  
Community Service ◽  
Identification Number ◽  
Starting Point ◽  
Stage 4 ◽  
Third Stage ◽  
Service Activity ◽  
Level Of Knowledge ◽  
Tax Reporting ◽  
Stage 1 ◽  
And Training

ABSTRACT One of the problems of MSME (Micro, Small, and Medium Entreprise) in fulfilling tax obligations is the difficulty for citizens to register to obtain a Taxpayer Identification Number (NPWP) where this NPWP is an important starting point in carrying out tax obligations, namely tax calculation, tax reporting, and tax payment. However, the low level of knowledge and skill conditions in the NPWP registration sector for both individuals and MSMEs. This community service aims to provide socialization to residents, especially the perpetrators or owners of MSME in Sendangguwo Village, Tembalang District, the majority of them still find it difficult to register themselves to obtain NPWP. The subjects of this community service is people who do not yet have a Taxpayer Identification Number / NPWP to be able to register immediately, thus the details of the purpose of this service are to provide socialization about the importance of having a Taxpayer Identification Number / NPWP both personally and who have a MSME business and provide simulation training for registration to obtain a Taxpayer Identification Number / NPWP both online and offline. This community service activity is carried out in several stages, namely as follows. The first stage (1) is a survey of the service location. Followed by the second stage (2), namely the collection of village potential data and the role of the community. The third stage (3) is the preparation for the implementation of mentoring and training. And the last stage (4) is the implementation of mentoring and training. The results of the community service activity are Participants become more aware and can register a Taxpayer Identification Number (NPWP), This Community Service Program provides a module on how to register to obtain a Taxpayer Identification Number / NPWP, so that it can be used by residents and UMKM players in the context of registering a Taxpayer Identification Number / NPWP so that it can be used properly by MSME actors, With the eRegistration system, it makes it easier for residents and SMEs to register their Taxpayer Identification Number / NPWP.

Alterations in the number of motoneurons containing immunoreactive calcitonin gene-related peptide(CGRP)& choline acetyltransferase(ChAT) in the cervical spinal cord of the wobbler mouse during the development of the motoneuron disease

1995 ◽  
Vol 53 ◽  
pp. 970-971
Author(s):  
L. Vacca-Galloway ◽  
Y.Q. Zhang ◽  
P. Bose ◽  
S.H. Zhang
Keyword(s):  
Spinal Cord ◽  
Early Stage ◽  
Cervical Spinal Cord ◽  
Wild Type Mouse ◽  
Reflex Response ◽  
Mouse Strains ◽  
Behavioral Tests ◽  
Wobbler Mouse ◽  
Stage 4 ◽  
Stage 1

The Wobbler mouse (wr) has been studied as a model for inherited human motoneuron diseases (MNDs). Using behavioral tests for forelimb power, walking, climbing, and the “clasp-like reflex” response, the progress of the MND can be categorized into early (Stage 1, age 21 days) and late (Stage 4, age 3 months) stages. Age-and sex-matched normal phenotype littermates (NFR/wr) were used as controls (Stage 0), as well as mice from two related wild-type mouse strains: NFR/N and a C57BI/6N. Using behavioral tests, we also detected pre-symptomatic Wobblers at postnatal ages 7 and 14 days. The mice were anesthetized and perfusion-fixed for immunocytochemical (ICC) of CGRP and ChAT in the spinal cord (C3 to C5).Using computerized morphomety (Vidas, Zeiss), the numbers of IR-CGRP labelled motoneurons were significantly lower in 14 day old Wobbler specimens compared with the controls (Fig. 1). The same trend was observed at 21 days (Stage 1) and 3 months (Stage 4). The IR-CGRP-containing motoneurons in the Wobbler specimens declined progressively with age.

How well do voice-hearing assessment measures capture the positive experiences of individuals?

2019 ◽  
Author(s):  
Lucy Armstrong ◽  
Lorna Hogg ◽  
Pamela Charlotte Jacobsen
Keyword(s):  
Systematic Review ◽  
Lived Experience ◽  
Second Stage ◽  
The Third ◽  
Third Stage ◽  
Hearing Assessment ◽  
Positive Experiences ◽  
Assessment Measures ◽  
Stage 1 ◽  
The Voice

The first stage of this project aims to identify assessment measures which include items on voice-hearing by way of a systematic review. The second stage is the development of a brief framework of categories of positive experiences of voice hearing, using a triangulated approach, drawing on views from both professionals and people with lived experience. The third stage will involve using the framework to identify any positve aspects of voice-hearing included in the voice hearing assessments identified in stage 1.

scholarly journals Theoretical analysis and experimental research on multi-layer elastic damping track structure

2021 ◽  
Vol 13 (2) ◽  
pp. 168781402199497
Author(s):  
Guanghui Xu ◽  
Shengkai Su ◽  
Anbin Wang ◽  
Ruolin Hu
Keyword(s):  
Finite Element ◽  
Analytical Solution ◽  
Finite Element Simulation ◽  
Reaction Force ◽  
Vibration Reduction ◽  
Vertical Direction ◽  
Propagation Path ◽  
Track Structure ◽  
Test Results ◽  
Element Simulation

The increase of axle load and train speed would cause intense wheelrail interactions, and lead to potential vibration related problems in train operation. For the low-frequency vibration reduction of a track system, a multi-layer track structure was proposed and analyzed theoretically and experimentally. Firstly, the analytical solution was derived theoretically, and followed by a parametric analysis to verify the vibration reduction performance. Then, a finite element simulation is carried out to highlight the influence of the tuned slab damper. Finally, the vibration and noise tests are performed to verify the results of the analytical solution and finite element simulation. As the finite element simulation indicates, after installation of the tuned slab damper, the peak reaction force of the foundation can be reduced by 60%, and the peak value of the vertical vibration acceleration would decrease by 50%. The vibration test results show that the insertion losses for the total vibration levels are 13.3 dB in the vertical direction and 21.7 dB in the transverse direction. The noise test results show that the data of each measurement point is smoother and smaller, and the noise in the generating position and propagation path can be reduced by 1.9 dB–5.5 dB.

Novel staging classification of primary mitral regurgitation based on the presence of cardiac damage

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
A.L Van Wijngaarden ◽  
Y.L Hiemstra ◽  
P Van Der Bijl ◽  
V Delgado ◽  
N Ajmone Marsan ◽  
...  
Keyword(s):  
Mitral Regurgitation ◽  
Kidney Function ◽  
Left Ventricular ◽  
Prognostic Impact ◽  
Cardiac Damage ◽  
Stage 4 ◽  
All Cause Mortality ◽  
Primary Mitral Regurgitation ◽  
Stage 1 ◽  
Staging Classification

Abstract Background The indication for surgery in patients with severe primary mitral regurgitation (MR) is currently based on the presence of symptoms, left ventricular (LV) dilatation and dysfunction, atrial fibrillation and pulmonary hypertension. The aim of this study was to evaluate the prognostic impact of a new staging classification based on cardiac damage including the known risk factors but also including global longitudinal strain (GLS), severe left atrial (LA) dilatation and right ventricular (RV) dysfunction. Methods In total 614 patients who underwent surgery for severe primary MR with available baseline transthoracic echocardiograms were included. Patients were classified according to the extent of cardiac damage (Figure): Stage 0-no cardiac damage, Stage 1-LV damage, Stage 2-LA damage, Stage 3-pulmonary vasculature or tricuspid valve damage and Stage 4-RV damage. Patients were followed for all-cause mortality. Results Based on the proposed classification, 172 (28%) patients were classified as Stage 0, 102 (17%) as Stage 1, 134 (21%) as Stage 2, 135 (22%) as Stage 3 and 71 (11%) as Stage 4. The more advanced the stage, the older the patients were with worse kidney function, more symptoms and higher EuroScore. Kaplan-Meier curve analysis revealed that patients with more advanced stages of cardiac damage had a significantly worse survival (log-rank chi-square 35.2; p<0.001) (Figure). On multivariable analysis, age, male, chronic obstructive pulmonary disease, kidney function, and stage of cardiac damage were independently associated with all-cause mortality. For each stage increase, a 22% higher risk for all-cause mortality was observed (95% CI: 1.064–1.395; p=0.004). Conclusion In patients with severe primary MR, a novel staging classification based on the extent of cardiac damage, may help refining risk stratification, particularly including also GLS, LA dilatation and RV dysfunction in the assessment. Funding Acknowledgement Type of funding source: None

scholarly journals Proposal of a stage-by-stage design method and its application on a multi-stage multiphase pump based on numerical simulations

2021 ◽  
Vol 13 (1) ◽  
pp. 168781402098731
Author(s):  
Yi Shi ◽  
Hongwu Zhu
Keyword(s):  
Volume Fraction ◽  
Design Method ◽  
Oil Field ◽  
Stage Design ◽  
Multiphase Pump ◽  
Flow Parameters ◽  
Multi Stage ◽  
Comparison Results ◽  
Third Stage ◽  
Gas Volume

Rotodynamic multiphase pumps are usually equipped with many compression units to provide sufficient boosting pressure for the transportation of production fluid in gas oil field. It is a challenge to maintain pump performance while flow parameters in each stage vary due to the compressibility of gas-liquid phase. In this article, a stage-by-stage design method is proposed to improve the boosting capability of a multiphase pump. Variations of flow parameters in each stage are investigated based on computational fluid dynamics (CFD) numerical simulation. Available methods to determinate main impeller geometry parameters of impeller are discussed. The stage-by-stage design method is applied on a five-stage multiphase pump when the inlet gas volume fraction (GVF) are 30% and 50% separately. The second stage is modified base on its corresponding inlet flow parameters when inlet GVF is 30% while the second and third stage are modified when inlet GVF is 50%. Flow parameters, pressure distribution and velocity distribution are compared between the original pump and modified pump. Differential pressure of the modified pump increases by 53.72 kPa and 58.57 kPa respectively when inlet GVFs are 30% and 50%. The feasibility of the stage-by-stage design method is verified through the comparison results.

A Description of Middle School Male Singers’ Voice Change and Voice Part Assignment

2021 ◽  
pp. 875512332110182
Author(s):  
Ryan Austin Fisher ◽  
Nancy L. Summitt ◽  
Ellen B. Koziel
Keyword(s):  
Middle School ◽  
Sixth Grade ◽  
Eighth Grade ◽  
Voice Change ◽  
Stage 4 ◽  
Public Middle School ◽  
Middle School Choir ◽  
Choral Programs ◽  
Stage 1 ◽  
The Voice

The purpose of this study was to describe the voice change and voice part assignment of male middle school choir members. Volunteers ( N = 92) were recruited from three public middle school choral programs (Grades 6-8). Participants were audio-recorded performing simple vocal tasks in order to assess vocal range and asked to share the music they were currently singing in class. Results revealed 23.91% of participants’ voices could be categorized as unchanged, 14.13% as Stage 1, 3.26% as Stage 2, 10.87% as Stage 3, 26.09% as Stage 4, and 21.74% as Stage 5. The majority of sixth-grade participants were classified as unchanged or in Stage 1 of the voice change and the majority of eighth-grade participants were classified in Stages 4 to 5 of the voice change. Of the participants labeled “tenors” in their choir, over 60% were classified as either unchanged voices or in Stage 1 of the voice change.

scholarly journals Simulation of Energy Absorption Performance of the Couplers in Urban Railway Vehicles during a Heavy Collision

Machines ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 91
Author(s):  
Sunghyun Lim ◽  
Yong-hyeon Ji ◽  
Yeong-il Park
Keyword(s):  
Reaction Force ◽  
Crash Test ◽  
Railway Vehicle ◽  
Buffer System ◽  
Railway Vehicles ◽  
Hydraulic Shock Absorber ◽  
Coupling Buffer ◽  
Absorption Performance ◽  
Different Characteristics ◽  
The Impact

Railway vehicles are generally operated by connecting several vehicles in a row. Mechanisms connecting railway vehicles must also absorb front and rear shock loads that occur during a train’s operation. To minimize damage, rail car couplers are equipped with a buffer system that absorbs the impact of energy. It is difficult to perform a crash test and evaluate performance by applying a buffer to an actual railway vehicle. In this study, a simulation technique using a mathematical buffer model was introduced to overcome these difficulties. For this, a model of each element of the buffer was built based on the experimental data for each element of the coupling buffer system and a collision simulation program was developed. The buffering characteristics of a 10-car train colliding at 25 km/h were analyzed using a developed simulator. The results of the heavy collision simulation showed that the rubber buffer was directly connected to the hydraulic shock absorber in a solid contact state, and displacement of the hydraulic buffer hardly occurred despite the increase in reaction force due to the high impact speed. Since the impact force is concentrated on the vehicle to which the collision is applied, it may be appropriate to apply a deformation tube with different characteristics depending on the vehicle location.

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