| 1. |
- Carlberger, Andreas, 1992, et al.
(författare)
-
Numerical prediction of rail corrugation growth on curves
- 2016
-
Ingår i: Proceedings of the 19h Nordic Seminar on Railway Technology, September 14 - 15, Luleå, Sweden (2016).
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Rail corrugation (periodic surface irregularities at distinct wavelengths) is a problem experienced by many railway networks worldwide. Corrugation induces a pronounced dynamic wheel‒rail contact loading that leads to increased generation of noise and in severe cases even damage to vehicle and track components. The large magnitude creep forces and sliding between wheel and rail make corrugation especially prone to develop on curved track. The current work summarizes the results from a Master Thesis project performed in collaboration between Chalmers, ÅF Industry, Bombardier Transportation and Stockholm Public Transport. A time-domain model for the prediction of long-term growth of rail roughness has been developed, see Figure 1. Dynamic vehicle‒track interaction in a broad frequency range (at least up to 300 Hz) is simulated using the commercial software SIMPACK. Wheelset structural flexibility is accounted for by using modal parameters calculated for a finite element model. Non-Hertzian and non-steady wheel‒rail contact and associated generation of wear are calculated in a post-processing step in the software Matlab. Archard’s law is applied to model the sliding wear. A large number of train passages is accounted for by recurrent updating of the rail surface irregularity based on the calculated wear depth. The proposed prediction model is applied to investigate a curve on the Stockholm metro network exposed to severe corrugation growth.
|
|
| 2. |
- Nielsen, Jens, 1963, et al.
(författare)
-
Switch panel design based on simulation of accumulated rail damage in a railway turnout
- 2016
-
Ingår i: Wear. - : Elsevier BV. - 0043-1648. ; 366-367:SI, s. 241-248
-
Tidskriftsartikel (refereegranskat)abstract
- A methodology for numerical prediction of accumulated rail damage in railway turnouts is presented. Based on simulation of dynamic vehicle-track interaction followed by a discretisation of the conditions in each wheel-rail contact, distributions of rail wear are calculated by the Archard model of sliding wear, while surface initiated rolling contact fatigue (RCF) damage is evaluated by the Palmgren–Miner rule and an index building on shakedown theory. Partial slip in the wheel-rail contacts and variable amplitude loading are considered. For freight traffic in the diverging route, the influence of rail inclination and switch rail elevation on damage in the switch panel is investigated in a demonstration example. Two-point contact situations with one contact on the switch rail and one on top of the stock rail induce relative motion and slip between wheel and rail leading to high energy dissipation. In agreement with field observations, it is concluded that wear is the dominating damage mechanism on the gauge side of the switch rail while the risk for RCF is higher on the crowns of the switch and stock rails. For accurate prediction of rail life for given combinations of wheel/rail materials and traffic conditions, the methodology needs to be calibrated by field measurements.
|
|
| 3. |
- Nielsen, Jens, 1963, et al.
(författare)
-
Switch panel design based on simulation of accumulated rail damage in a railway turnout
- 2015
-
Ingår i: Proceedings of the 10th International International Conference on Contact Mechanics and Wear of Rail/Wheel Systems, Colorado Springs, USA, August-September 2015.
-
Konferensbidrag (refereegranskat)abstract
- A methodology for numerical prediction of accumulated rail damage in railway turnouts is presented. Based onsimulation of dynamic vehicle‒track interaction followed by a discretisation of the conditions in each wheel‒railcontact, distributions of rail wear are calculated by the Archard model of sliding wear, while surface initiated rollingcontact fatigue (RCF) damage is evaluated by the Palmgren-Miner rule and an index building on shakedown theory.Partial slip in the wheel‒rail contacts and variable amplitude loading are considered. For freight traffic in the divergingroute, the influence of rail inclination and switch rail height on damage in the switch panel is investigated in ademonstration example. Two-point contact situations with one contact on the switch rail and one on top of the stock rail induce relative motion and slip between wheel and rail leading to high energy dissipation. In agreement with fieldobservations, it is concluded that wear is the dominating damage mechanism on the gauge side of the switch rail whilethe risk for RCF is higher on the crowns of the switch and stock rails. For accurate prediction of rail life for givencombinations of wheel/rail materials and traffic conditions, the methodology needs to be calibrated by fieldmeasurements.
|
|
| 4. |
- Torstensson, Peter, 1981-, et al.
(författare)
-
Wheel–rail impact loads and noise generated at railway crossings : Influence of vehicle speed and crossing dip angle
- 2019
-
Ingår i: Journal of Sound and Vibration. - : Academic Press. - 0022-460X .- 1095-8568. ; 456, s. 119-136
-
Tidskriftsartikel (refereegranskat)abstract
- Wheel–rail impact loads and noise at railway crossings are calculated by applying a hybrid prediction model. It combines the simulation of non-linear vertical dynamic vehicle‒track interaction in the time domain and the prediction of sound pressure level using a linear frequency-domain model. The two models are coupled based on the concept of an equivalent roughness spectrum. The time-domain model uses moving Green's functions for the linear vehicle and track models, accounting for wheel structural flexibility and a discretely supported rail with spatially-varying beam properties, and a non-Hertzian wheel–rail contact model. Three-dimensional surface geometry of the wheel and crossing is accounted for in the solution of the wheel–rail contact. The hybrid model is compared against field measurements and is demonstrated by investigating the influence of vehicle speed and crossing geometry on the radiated impact noise. Based on simulation results, it is concluded that the impact loads and noise can be mitigated by reducing the effective dip angle at the crossing, which is determined by the vertical trajectory of the wheel when making the transition between wing rail and crossing nose.
|
|
| 5. |
- Andersson, Robin, 1986, et al.
(författare)
-
An efficient approach to the analysis of rail surface irregularities accounting for dynamic train–track interaction and inelastic deformations
- 2015
-
Ingår i: Vehicle System Dynamics. - : Informa UK Limited. - 1744-5159 .- 0042-3114. ; 53:11, s. 1667-1685
-
Tidskriftsartikel (refereegranskat)abstract
- A two-dimensional computational model for assessment of rolling contact fatigue induced by discrete rail surface irregularities, especially in the context of so-called squats, is presented. Dynamic excitation in a wide frequency range is considered in computationally efficient time-domain simulations of high-frequency dynamic vehicle-track interaction accounting for transient non-Hertzian wheel–rail contact. Results from dynamic simulations are mapped onto a finite element model to resolve the cyclic, elastoplastic stress response in the rail. Ratcheting under multiple wheel passages is quantified. In addition, low cycle fatigue impact is quantified using the Jiang–Sehitoglu fatigue parameter. The functionality of the model is demonstrated by numerical examples.
|
|
| 6. |
- Andersson, Robin, 1986, et al.
(författare)
-
Integrated analysis of dynamic vehicle-track interaction and plasticity induced damage in the presence of squat defects
- 2015
-
Ingår i: Proceedings of the 10th International International Conference on Contact Mechanics and Wear of Rail/Wheel Systems, Colorado Springs, USA, August-September 2015.
-
Konferensbidrag (refereegranskat)abstract
- Despite significant efforts, the mechanisms behind the formation of squats – a form of rolling contact fatigue damage – are not fully understood. This study employs numerical simulations to investigate the propensity of squat initiation in the vicinity of small, isolated rail surface irregularities. Time domain dynamic vehicle–track interaction analysis is used to obtain wheel–rail contact stress distributions, which are mapped onto a continuum finite element model that accounts for plastic deformation of the rail material. The evaluated stress and strain fields are quantified using two RCF impact measures: accumulated effective strain and the Jiang-Sehitoglu multiaxial low cycle fatigue parameter. It is shown that the RCF impact increases with increasing size of the surface irregularity and that clustering of irregularities might strongly promote RCF. The friction coefficient is identified as a very influential parameter. Further, the effect of variations in friction along the rail is evaluated. It is shown that a short rail section of low friction results in fairly high RCF impact.
|
|
| 7. |
- Andersson, Robin, 1986, et al.
(författare)
-
Integrated analysis of dynamic vehicle–track interaction and plasticity induced damage in the presence of squat defects
- 2016
-
Ingår i: Wear. - : Elsevier BV. - 0043-1648. ; 366-367:SI, s. 139-145
-
Tidskriftsartikel (refereegranskat)abstract
- Despite significant efforts, the mechanisms behind the formation of squats – a form of rolling contact fatigue (RCF) damage – are not fully understood. This study employs numerical simulations to investigate the propensity of squat initiation in the vicinity of small, isolated rail surface irregularities. Time-domain dynamic vehicle–track interaction analysis is used to obtain wheel–rail contact stress distributions, which are mapped onto a continuum finite element model that accounts for plastic deformation of the rail material. The evaluated stress and strain fields are quantified using two RCF impact measures: accumulated effective strain and the Jiang–Sehitoglu multiaxial low cycle fatigue parameter. It is shown that the RCF impact increases with increasing size of the surface irregularity and that clustering of irregularities might strongly promote RCF. The friction coefficient is identified as a very influential parameter and also the effect of variations in friction along the rail is evaluated.
|
|
| 8. |
- Andersson, Robin, 1986, et al.
(författare)
-
The influence of rail surface irregularities on contact forces and local stresses
- 2015
-
Ingår i: Vehicle System Dynamics. - : Informa UK Limited. - 1744-5159 .- 0042-3114. ; 53:1, s. 68-87
-
Tidskriftsartikel (refereegranskat)abstract
- The effect of initial rail surface irregularities on promoting further surface degradation is investi-gated. The study concerns rolling contact fatigue formation, in particular in the form of the so-calledsquats. The impact of surface irregularities in the form of dimples is quantified by peak magnitudesof dynamic contact stresses and contact forces. To this end simulations of two-dimensional (laterextended to three-dimensional) vertical dynamic vehicle–track interaction are employed. The mostinfluencing parameters are identified. It is shown that even very shallow dimples might have a largeimpact on local contact stresses. Peak magnitudes of contact forces and stresses due to the influenceof rail dimples are shown to exceed those due to rail corrugation.
|
|
| 9. |
- Carlberger, Andreas, 1992, et al.
(författare)
-
An iterative methodology for the prediction of dynamic vehicle–track interaction and long-term periodic rail wear
- 2018
-
Ingår i: Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit. - : SAGE Publications. - 0954-4097 .- 2041-3017. ; 232:6, s. 1718-1730
-
Tidskriftsartikel (refereegranskat)abstract
- In this study, a versatile numerical method for the prediction of long-term growth of rail roughness is presented and its functionality is demonstrated for the development of rail corrugation on small radius curves. The procedure includes two sub-modules: (1) a time-domain model for the simulation of dynamic vehicle–track interaction in a wide range of frequencies by using a commercial software for multibody dynamics and (2) a post-calculation of sliding wear based on the Archard’s model in combination with a non-Hertzian and transient wheel–rail contact model. The structural flexibility of the wheelset is accounted for by using the finite element method. The rail wear generated by a large number of passing trains is assessed by recurrently updating the rail surface based on the wear depth calculated in each post- processing step. The current work sets out from a previous study in which a model for the prediction of long-term growth of rail roughness on small radius curves was developed in a general-purpose programming language. By transfer- ring the model into a commercial software, the aim is to develop an engineering tool that is more applicable for different operational conditions, such as various vehicle and track designs and track alignments. The proposed method is verified by comparing the simulation results against those obtained with the pre-existing software. Conditions similar to a 120 m radius curve on the Stockholm metro exposed to corrugation growth on the low rail are considered. The corrugation is found to be generated by the leading wheelsets. The prevailing wavelength-fixing mechanisms are identified and discussed.
|
|
| 10. |
- Li, Xin, 1985, et al.
(författare)
-
Simulation of vertical dynamic vehicle-track interaction in a railway crossing using Green's functions
- 2017
-
Ingår i: Journal of Sound and Vibration. - : Elsevier BV. - 1095-8568 .- 0022-460X. ; 410, s. 318-329
-
Tidskriftsartikel (refereegranskat)abstract
- Vertical dynamic vehicle-track interaction in the through route of a railway crossing is simulated in the time domain based on a Green's function approach for the track in combination with an implementation of Kalker's variational method to solve the non-Hertzian, and potentially multiple, wheel-rail contact. The track is described by a linear, three-dimensional and non-periodic finite element model of a railway turnout accounting for the variations in rail cross-sections and sleeper lengths, and including baseplates and resilient elements. To reduce calculation time due to the complexity of the track model, involving a large number of elements and degrees-of-freedom, a complex-valued modal superposition with a truncated mode set is applied before the impulse response functions are calculated at various positions along the crossing panel. The variation in three-dimensional contact geometry of the crossing and wheel is described by linear surface elements. In each time step of the contact detection algorithm, the lateral position of the wheelset centre is prescribed but the contact positions on wheel and rail are not, allowing for an accurate prediction of the wheel transition between wing rail and crossing rail. The method is demonstrated by calculating the wheel-rail impact load and contact stress distribution for a nominal S1002 wheel profile passing over a nominal crossing geometry. A parameter study is performed to determine the influence of vehicle speed, rail pad stiffness, lateral wheelset position and wheel profile on the impact load generated at the crossing. It is shown that the magnitude of the impact load is more influenced the wheel-rail contact geometry than by the selection of rail pad stiffness.
|
|
| 11. |
- Li, Xin, 1985, et al.
(författare)
-
Simulation of wheel–rail impact load and sleeper–ballast contact pressure in railway crossings using a Green's function approach
- 2019
-
Ingår i: Journal of Sound and Vibration. - : Elsevier BV. - 1095-8568 .- 0022-460X. ; 463
-
Tidskriftsartikel (refereegranskat)abstract
- A method for the simulation of dynamic vehicle–track interaction and evaluation of measures to improve the design of railway crossings is presented. To accurately represent the high-frequency dynamics and non-linear contact conditions of the vehicle–track system, the vertical interaction between a wheelset and the crossing is simulated in the time domain using a Green's function approach based on extensive finite element models of track and wheelset in combination with an implementation of Kalker's variational method to solve the non-Hertzian, and potentially multiple, wheel–rail contact. Both wheels of the wheelset in simultaneous contact with the crossing rail and the outer rail are considered. Rigid and flexible wheelset models are compared. The sampled contact geometry of the crossing, including the discrete irregularity between the wing rail and the crossing nose, is used to determine a three-dimensional surface geometry between each pair of adjacent rail cross-sections. A parameter study is performed to investigate the influence of crossing design on the maximum vertical wheel–rail contact force and the contact pressure generated at the sleeper–ballast interface. It is concluded that a design with a combination of increased sleeper width, softer rail pads and implementation of under sleeper pads (USP) will reduce the track stiffness gradients in the crossing panel and mitigate the risk of differential track settlement by lowering the sleeper–ballast contact pressure.
|
|
| 12. |
- Li, Xin, 1985, et al.
(författare)
-
Vertical dynamic vehicle-track interaction in a railway crossing predicted by moving Green's functions
- 2016
-
Ingår i: 24th Symposium of the International Association for Vehicle System Dynamics, IAVSD 2015; Graz; Austria; 17 August 2015 through 21 August 2015. - : CRC Press. ; , s. 1319-1327
-
Konferensbidrag (refereegranskat)abstract
- A versatile and computationally efficient method for simulation of high-frequency dynamic vehicle–track interaction in a railway crossing is presented. The track model is based on a linear, time-invariant and non-periodic finite element model of a railway turnout accounting for variations in rail cross-sections and sleeper lengths, and including baseplates and resilient elements. To account for the longitudinal motion of the wheel, a set of moving Green’s functions is pre-calculated to represent the dynamics of the crossing. The lateral position of the wheel centre (but not the contact positions on wheel and rail) is prescribed and could be determined by a previous simulation of dynamic vehicle–track interaction using a multibody dynamics software. The vehicle model includes one half of a wheelset and the primary suspension. In each time-step of the simulation, the three-dimensional surface geometry of crossing and wheel is described by fournoded linear elements. Vertical non-Hertzian (potentially multiple) wheel–rail contact is solved by an implementation of Kalker’s variational method CONTACT. The method is demonstrated by calculating the impact load and wheel–rail contact stress distribution for the case with a nominal S1002 wheel profile passing over a nominal crossing geometry.
|
|
| 13. |
- Pieringer, Astrid, 1979, et al.
(författare)
-
Curve squeal of rail vehicles: Linear stability analysis and non-linear time-domain simulation
- 2016
-
Ingår i: Civil-Comp Proceedings. - 1759-3433. ; 110
-
Tidskriftsartikel (refereegranskat)abstract
- Railway curve squeal arises from self-excited vibrations during curving. In this paper, a combination of a frequency-and a time-domain approach for curve squeal is applied in order to compare and evaluate the two different approaches. In the frequency-domain, linear stability is investigated through complex eigenvalue analysis. The time-domain model is based on a Green's functions approach and uses a convolution procedure to obtain the system response. To ensure comparability, the same submodels are implemented in both squeal models. The wheel model includes a single flexible wheel and accounts for inertia effects due to rotation adopting Eulerian coordinates. The track is modelled using the moving element method technique corresponding to a finite element mesh that travels with the vehicle speed. Coulomb's law with a constant friction coefficient is applied to model the local friction characteristics in the contact zone. The frictional instability arises due to geometrical coupling. The rolling contact model applied is Kalker's variational method in the time domain and a linearized version of this method in the frequency domain. Conditions similar to those of a curve on the Stockholm metro exposed to severe curve squeal are studied with both squeal models. The influence of the wheel-rail friction coefficient and the direction of the resulting creep force on the occurrence of squeal is investigated for vanishing train speed. The results of both models show similar tendencies, but differ in the predicted squeal frequencies.
|
|
| 14. |
- Pieringer, Astrid, 1979, et al.
(författare)
-
Investigation of railway curve squeal using a combination of frequency- and time-domain models
- 2016
-
Ingår i: Proceedings of the 12h International Workshop on Railway Noise (IWRN12), Terrigal, Australia, September 12-16. ; , s. 444 - 451
-
Konferensbidrag (refereegranskat)abstract
- Railway curve squeal arises from self-excited vibrations during curving. In this paper, a frequency- and a timedomainapproach for curve squeal are compared. In particular, the capability of the frequency-domain model topredict the onset of squeal and the squeal frequencies is studied. In the frequency-domain model, linear stabilityis investigated through complex eigenvalue analysis. The time-domain model is based on a Green's functionsapproach and uses a convolution procedure to obtain the system response. To ensure comparability, the samesubmodels are implemented in both squeal models. The structural flexibility of a rotating wheel is modelled byadopting Eulerian coordinates. To account for the moving wheel‒rail contact load, the so-called moving elementmethod is used to model the track. The local friction characteristics in the contact zone is modelled inaccordance with Coulomb's law with a constant friction coefficient. The frictional instability arises due togeometrical coupling. In the time-domain model, Kalker's non-linear, non-steady state rolling contact modelincluding the algorithms NORM and TANG for normal and tangential contact, respectively, is solved in eachtime step. In the frequency-domain model, the normal wheel/rail contact is modelled by a linearization of theforce-displacement relation obtained with NORM around the quasi-static state and full-slip conditions areconsidered in tangential direction. Conditions similar to those of a curve on the Stockholm metro exposed tosevere curve squeal are studied with both squeal models. The influence of the wheel-rail friction coefficient andthe direction of the resulting creep force on the occurrence of squeal is investigated for vanishing train speed. Results from both models are similar in terms of the instability range in the parameter space and the predictedsqueal frequencies.
|
|
| 15. |
- Pieringer, Astrid, 1979, et al.
(författare)
-
Investigation of railway curve squeal using a combination of frequency- and time-domain models
- 2018
-
Ingår i: Notes on Numerical Fluid Mechanics and Multidisciplinary Design. - Cham : Springer International Publishing. - 1612-2909 .- 1860-0824. ; 139, s. 83-95, s. 83-95
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Railway curve squeal arises from self-excited vibrations during curving. In this paper, a frequency- and a time-domain approach for curve squeal are compared. In particular, the capability of the frequency-domain model to predict the onset of squeal and the squeal frequencies is studied. In the frequency-domain model, linear stability is investigated through complex eigenvalue analysis. The time-domain model is based on a Green’s function approach and uses a convolution procedure to obtain the system response. To ensure comparability, the same submodels are implemented in both squeal models. The structural flexibility of a rotating wheel is modelled by adopting Eulerian coordinates. To account for the moving wheel–rail contact load, the so-called moving element method is used to model the track. The local friction characteristics in the contact zone are modelled in accordance with Coulomb’s law with a constant friction coefficient. The frictional instability arises due to geometrical coupling. In the time-domain model, Kalker’s non-linear, non-steady state rolling contact model including the algorithms NORM and TANG for normal and tangential contact, respectively, is solved in each time step. In the frequency-domain model, the normal wheel/rail contact is modelled by a linearization of the force-displacement relation obtained with NORM around the quasi-static state and full-slip conditions are considered in the tangential direction. Conditions similar to those of a curve on the Stockholm metro exposed to severe curve squeal are studied with both squeal models. The influence of the wheel-rail friction coefficient and the direction of the resulting creep force on the occurrence of squeal is investigated for vanishing train speed. Results from both models are similar in terms of the instability range in the parameter space and the predicted squeal frequencies.
|
|
| 16. |
- Torstensson, Peter, 1981, et al.
(författare)
-
Hybrid model for prediction of impact noise generated at railway crossings
- 2016
-
Ingår i: Proceedings of the 12h International Workshop on Railway Noise (IWRN12), Terrigal, Australia, September 12-16 (2016). ; , s. 539 - 545
-
Konferensbidrag (refereegranskat)abstract
- A hybrid model for the prediction of impact noise at railway crossings is presented. The hybrid model combines the simulation of vertical wheel‒rail contact force in the time domain and the prediction of sound pressure level using a linear frequency-domain model. The time-domain model uses moving Green’s functions for the vehicle and track models (accounting for wheel flexibility and a discretely supported rail with space-variant beam properties) and a non-Hertzian wheel‒rail contact model. The time-domain and frequency-domain models are coupled based on the concept of an equivalent roughness spectrum. The model is demonstrated by investigating the influence of axle load, vehicle speed and wheel profile on generated impact noise levels. A negligible influence on impact noise is observed for axle loads in the interval 15 – 25 tonnes. On the other hand, increasing vehicle speed from 80 km/h to 150 km/h, or comparing a nominal S1002 wheel profile with a severely hollow worn profile, result in substantially higher levels of impact noise; for the given wheel and track conditions the differences are in the order of 10 dB(A).
|
|
| 17. |
- Torstensson, Peter, 1981, et al.
(författare)
-
Hybrid model for prediction of impact noise generated at railway crossings
- 2018
-
Ingår i: Notes on Numerical Fluid Mechanics and Multidisciplinary Design. - Cham : Springer International Publishing. - 1612-2909 .- 1860-0824. ; 139, s. 759-769, s. 759-769
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- A hybrid model for the prediction of impact noise at railway crossings is presented. The hybrid model combines the simulation of vertical wheel‒rail contact force in the time domain and the prediction of sound pressure level using a linear frequency-domain model. The time-domain model uses moving Green’s functions for the vehicle and track models (accounting for wheel flexibility and a discretely supported rail with space-variant beam properties) and a non-Hertzian wheel‒rail contact model. The time-domain and frequency-domain models are coupled based on the concept of an equivalent roughness spectrum. The model is demonstrated by investigating the influence of axle load, vehicle speed and wheel profile on generated impact noise levels. A negligible influence on impact noise is observed for axle loads in the interval 15–25 tonnes. On the other hand, increasing vehicle speed from 80 to 150 km/h, or comparing a nominal S1002 wheel profile with a severely hollow worn profile, result in substantially higher levels of impact noise; for the given wheel and track conditions the differences are in the order of 10 dB(A).
|
|
| 18. |
- Torstensson, Peter, 1981-, et al.
(författare)
-
Prognosmetod för framtida kompetens- och resursbehov knutet till svensk infrastruktur för spårburen trafik : delrapport 1 av 3 i projektet Prognosmodell för framtida kompetens- och resursbehov knutet till svensk infrastruktur för spårburen trafik
- 2019
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Utvecklingen inom järnvägen drivs av en ökande efterfrågan på hållbara och punktliga transporter från både näringsliv och en växande befolkning. Jämfört med 2014 prognostiserar Trafikverket en ökning av persontransportarbetet på järnväg med 54 % fram till 2040. Trafikverket beskriver i Nationell plan för transportsystemet 2018–2029 den största satsningen på järnvägen i modern tid. Detta inkluderar t.ex. deletapper av höghastighetsjärnvägsnätet med en planerad total slutlig längd på 1 500 km. Därutöver tillkommer insatser som övriga infrastrukturförvaltare i Sverige planerar att genomföra. Branschen har belyst behovet av kunskapsuppbyggnad och kompetensförstärkning för att kunna möta dessa framtida behov. Inom järnvägsteknikeryrken är kompetensbristen redan betydande och en aktuell svårighet för spårentreprenadföretagen att hantera. En utredning från Sveriges Byggindustrier bedömer att det inom några år kommer råda brist på 1 700 nyckelpersoner inom dessa yrkesgrupper.Denna rapport redovisar resultatet från den första arbetsetappen i ett större forskningsarbete med syfte att utveckla en praktiskt användbar modell för att prognostisera framtida kompetens- och resursbehov knutet till svensk infrastruktur för spårburen trafik. Projektet leds av Statens väg- och transportforskningsinstitut (VTI) med finansiering från, och i samarbete med, Trafikverket. Som ägare av stora infrastrukturanläggningar för spårburen trafik deltar Region Stockholm (SL), Trafikkontoret i Göteborg (Göteborgs spårvägar) samt Norrköpings spårvägar i projektets referensgrupp. Resultatet från projektet förväntas bli värdefullt ur flera aspekter. Bland annat som beslutsunderlag för kompetensförsörjningsinsatser så som utökning av antalet utbildningsplatser och utformningen av innehållet hos desamma, samt åtgärder för att öka branschens attraktionskraft. Vidare möjliggör prognosmetoden för branschaktörer att göra långsiktig strategisk planering som motsvarar och anpassas efter tillgången på resurser och kompetens.
|
|
| 19. |
- Torstensson, Peter, 1981, et al.
(författare)
-
Rail corrugation growth on curves - measurements, modelling and mitigation
- 2015
-
Ingår i: Notes on Numerical Fluid Mechanics and Multidisciplinary Design. - Berlin, Heidelberg : Springer Berlin Heidelberg. - 1612-2909 .- 1860-0824. ; 126, s. 659-666
-
Tidskriftsartikel (refereegranskat)abstract
- The development of rail corrugation (so called rutting corrugation) on a 120 m radius curve on the metro of Stockholm Public Transport was studied by field measurements, laboratory measurements and numerical simulations. The corrugation develops exclusively on the (inner) low rail with wavelengths of about 5 cm and 8 cm. A time-domain model for prediction of long-term roughness growth on small radius curves is developed and validated against measured data. The wavelength-fixing mechanisms of the corrugation are bending eigenmodes of the leading wheelsets. The application of a friction modifier effectively mitigates the problem.
|
|
| 20. |
- Torstensson, Peter, 1981-, et al.
(författare)
-
Use of numerical simulation to map and mitigate railway particle emissions
- 2019
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This feasibility study is an interdisciplinary collaboration between three research institutes (VTI, Chalmers University of Technology and RISE) and a railway brake manufacturer (Faiveley Transport Nordic). Senior researchers specialized on numerical modelling of friction brakes and on particle matters (PM), are combined with expertise in the field of train driving simulation to reduce railway’s impact on environment and human health. The train driving simulator of VTI is further developed to account for the wear generated at the brake blocks and in the wheel‒rail contact. A literature study that focuses on prediction of railway particle emissions is presented
|
|
