Simulation tools for railroad dynamics
Jiang, Dezhi (2020)
Diplomityö
2020
School of Energy Systems, Konetekniikka
Kaikki oikeudet pidätetään.
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi-fe2020120299134
https://urn.fi/URN:NBN:fi-fe2020120299134
Tiivistelmä
The objective of the work is to evaluate the accuracy of two methods which are implemented in MATLAB (by Xinxin Yu) against a commercial software in case of Manchester Benchmark parameters (Iwnick, 1998). Two methods and the software above are all simulation tools for railway dynamics. The methods are the lookup table method (Escalona and Aceituno, 2019) and knife-edge-equivalent contact constraint (KEC) method (Escalona et al., 2019). The method of evaluation is comparing the simulation results of above two methods with the results from commercial software, Universal Mechanism (UM).
Theoretical foundations for UM including information about wheel rail pair for this thesis, hunting, suspension systems, as well as cubic spline interpolation for profiles and irregularity are introduced. Integrators and contact models of UM, GENSYS and VI-Rail are investigated. Then a step-by-step example of building bogie with a primary suspension system in UM is shown.
Comparison results between above mentioned methods and UM are shown in Chapter 4. The first simulation is single wheelset forward motion on a tangent track with different speeds. Hunting frequency calculated by using Klingel’s formula is the same as the frequency measured in simulation. During second set of simulation, the single wheelset travelled on a large radius curve and a small radius curve accordingly. The calculation result of the symmetry axis is the same as it measured from the result figure. Then the whole vehicle according to Manchester Benchmark standard (Iwnick, 1998) is applied. The whole vehicle is simulated on the small curve track. First travelled without irregularity, then with irregularities. The output results are the lateral displacements, and the yaw angles of each wheelset. Results from the lookup table method, the KEC method and UM agree well with each other. It can be concluded that lookup table method and the knife-edge-equivalent contact constraint method in case of Manchester Benchmark are verified against UM because they can get very close results with commercial software.
Theoretical foundations for UM including information about wheel rail pair for this thesis, hunting, suspension systems, as well as cubic spline interpolation for profiles and irregularity are introduced. Integrators and contact models of UM, GENSYS and VI-Rail are investigated. Then a step-by-step example of building bogie with a primary suspension system in UM is shown.
Comparison results between above mentioned methods and UM are shown in Chapter 4. The first simulation is single wheelset forward motion on a tangent track with different speeds. Hunting frequency calculated by using Klingel’s formula is the same as the frequency measured in simulation. During second set of simulation, the single wheelset travelled on a large radius curve and a small radius curve accordingly. The calculation result of the symmetry axis is the same as it measured from the result figure. Then the whole vehicle according to Manchester Benchmark standard (Iwnick, 1998) is applied. The whole vehicle is simulated on the small curve track. First travelled without irregularity, then with irregularities. The output results are the lateral displacements, and the yaw angles of each wheelset. Results from the lookup table method, the KEC method and UM agree well with each other. It can be concluded that lookup table method and the knife-edge-equivalent contact constraint method in case of Manchester Benchmark are verified against UM because they can get very close results with commercial software.