INGENIEURFAKULTÄT BAU GEO UMWELT Lehrstuhl für Verkehrswegebau The influence of track quality to the performance of vehicle-track interaction Duo Liu Vollständiger Abdruck der von der Ingenieurfakultät Bau Geo Umwelt der Technischen Universität München zur Erlangung des akademischen Grades eines Doktor-Ingenieurs genehmigten Dissertation. Vorsitzender: Univ.-Prof. Dr.-Ing. Gebhard Wulfhorst Prüfer der Dissertation: 1. Univ.-Prof. Dr.-Ing. Stephan Freudenstein 2. Univ.-Prof. Dr.-Ing. Ullrich Martin, Universität Stuttgart 3. Univ.-Prof. Dipl.-Ing. Dr. techn. Peter Veit, Technische Universität Graz / Österreich Die Dissertation wurde am 07.04.2015 bei der Technischen Universität München eingereicht und durch die Ingenieurfakultät Bau Geo Umwelt am 12.10.2015 angenommen. Table of contents Table of Contents Terms and definitions .............................................................................................. V Abstract .................................................................................................................... VI 1. INTRODUCTION ................................................................................................. 1 1.1. Background of the research .............................................................................. 1 1.2. Scope and objectives ......................................................................................... 2 2. STATE OF TECHNOLOGY ................................................................................. 4 2.1. Track geometry (Non-recoverable track settlement) .................................... 4 2.1.1. Track recording wagon (TRW) ......................................................................... 4 2.1.2. Linear-Time-Invariant (LTI) analysis [06] .......................................................... 5 2.1.3. Track irregularity and Power-Spectral-Density function (PSD) [09].............. 6 2.2. Track stiffness (recoverable track deflection under loading) ....................... 7 2.2.1. Load distribution and elastic deflection line (static) ....................................... 7 2.2.2. Characteristics of the stiffness and damping behavior along the track ..... 9 2.3. Modeling approach for analyzing railway track dynamics .......................... 10 2.3.1. Analytic models and calculation of wheel dynamic load ............................ 11 2.3.2. Numerical models ............................................................................................. 12 2.3.3. Finite-Element-Method (FEM) ........................................................................ 13 2.3.4. Multi-Body-Simulation (MBS) .......................................................................... 14 2.3.5. Comparisons and co-simulation ..................................................................... 15 3. PILOT SECTIONS AND DESIGN OF FIELD MEASUREMENT ....................... 18 3.1. Introduction ........................................................................................................ 18 3.2. Selection of pilot sections ................................................................................ 18 3.3. Test program ..................................................................................................... 19 3.3.1. Determination of track geometry (plastic track deformation, unloaded) 20 3.3.2. Measurement of elastic rail deflection (quasi-static) ................................... 21 3.3.3. Installation of strain gauges ............................................................................ 23 I Table of contents 3.3.4. Recording the vertical track response under running trains ...................... 24 3.3.5. Measurement of vertical acceleration level .................................................. 25 3.4. Long-term effects .............................................................................................. 27 3.5. Vehicle information ........................................................................................... 27 3.5.1. Vehicle information in sections 1 and 2 (German railway high speed line) 28 3.5.2. Vehicle information in sections 3 and 4 (Austrian railway high speed line) 30 4. FIELD MEASUREMENT AND DATA ANALYSIS ............................................. 32 4.1. Track geometry and irregularity (plastic settlement) ................................... 32 4.1.1. Calculation of absolute track geometry ......................................................... 32 4.1.2. Statistical analysis of the measured data ..................................................... 33 4.1.3. Calculation of track quality parameters using Power-Spectral-Density function (PSD) ................................................................................................... 34 4.2. Rail deflection under static loading (elastic deflection) ............................... 39 4.3. Dynamic rail bending behavior ....................................................................... 41 4.3.1. Automatic peak finding of the measured dynamic strain ........................... 42 4.3.2. Calibration runs with quasi-static loading ..................................................... 43 4.3.3. Rail bending behavior under operational train runs .................................... 45 4.4. Test of track vibration level ............................................................................. 51 4.4.1. Track vibration level under impact load ........................................................ 52 4.4.2. Track vibration level under operational trains .............................................. 53 4.5. Data provision for the numerical simulations ............................................... 55 5. THE NUMERICAL MODELING ......................................................................... 57 5.1. Introduction ........................................................................................................ 57 5.2. Model 1 (FEM) – Calibration of the elastic track model based on field side Benkelman measurement ................................................................................................. 59 5.2.1. Introduction and modeling approach ............................................................. 59 5.2.2. Model setup and boundary condition ............................................................ 60 5.2.3. The iterative process ........................................................................................ 62 II Table of contents 5.2.4. Results and conclusions .................................................................................. 66 5.2.5. Automation of the iteration methods (Co-Simulation with ANSYS and MATLAB) 68 5.3. Model 2 (MBS) – Dynamic simulation of the vehicle track interaction with pre-defined track excitations ............................................................................................ 70 5.3.1. Background and introduction .......................................................................... 70 5.3.2. Modeling of the vehicle .................................................................................... 70 5.3.3. Inclusion of measured track excitation .......................................................... 72 5.3.4. Modeling results ................................................................................................ 73 5.4. Model 3 (Co-simulation with FEM and MBS) – Calibration of the quasi- static wheel rail load under modal represented elastic track from FEM ................... 75 5.4.1. Background and introduction .......................................................................... 75 5.4.2. Model condensation and modal analysis ...................................................... 76 5.4.3. Adjustment of the vehicle model with contact markers and model calculation 79 5.4.4. Simulation results ............................................................................................. 80 5.5. Model 4 (Co-simulation with FEM and MBS) – Calculation of the dynamic wheel load under elastic track with irregularities (V = 160 km/h) ............................... 81 5.5.1. Background and introduction .......................................................................... 81 5.5.2. Simulation results ............................................................................................. 82 5.6. Conclusion and outcome ................................................................................. 84 6. FEEDBACK BETWEEN VEHICLE AND TRACK UNDER TRACK SIDED EXCITATIONS ......................................................................................................... 86 6.1. The limitation of the existing method on evaluation of the track quality and preliminary studies ....................................................................... 86 6.2. The improvement of track quality evaluation method ................................. 88 6.3. Variation of the included influence parameters............................................ 89 6.4. Distribution of dynamic wheel load according to standard track quality factors (Y = 6) ....................................................................................... 91 6.5. Simulation results under purely track geometry variations (Z = 0) ........... 93 6.6. Simulation results under purely track stiffness variations (Y = 0) ............. 94 III Table of contents 6.7. The “hybrid” simulations .................................................................................. 95 6.8. ESD analysis and possibilities of improving existing