Colloquium #26

March 23, 2017 in

Monthly Railway Colloquium at TU Delft. Thursday March 23, 2017 the following researchers will present their work: Dr. Zhiwei Qian [Postdoc Researcher] and Zilog Wei and Xiangming Liu [PhD’s at TU Delft].

Date:         Thursday March 23, 2017
Time:        4.00pm – 6.00pm [followed by drinks at PSOR]
Location:  Faculty of Civil Engineering and Geosciences [TU Delft]
Room:       CEG 2.62


Insight into Fourier Analysis
Zhiwei Qian [Postdoc Researcher at TU Delft]

In this presentation, the popular mathematical tool Fourier analysis is reviewed and interpreted, including Fourier series and Fourier transform. A number of graphic images are used to illustrate the basic concepts and their relations in Fourier analysis, such as time domain, frequency domain and spectrum. The lecture intends to help students have a more clear picture about Fourier analysis and enhance their understanding in an interesting approach.


Monitoring the deterioration of railway infrastructure based on 3D profile measurement
Zilong Wei [PhD Researcher at TU Delft]

This talk introduces a 3D profile measurement system which can be used to monitor the deterioration of railway infrastructure. The system composes of a laser-based non-contact apparatus HandyScan and its integrated software VX elements. With the system, the evolution of wheel and rail profile s during long-term usage can be extracted through the comparison among several measurements. Moreover, the measured profiles can serve as input for the numerical simulation. In comparison to the commonly used 2D profile measurements, the proposed 3D measurement is not limited to cross-sections, so that short wavelength anomalies can be completely captured.


Long term performance monitoring of a turnout crossing
Xiangming Liu [PhD Researcher at TU Delft]

The dynamic performance of a problematic turnout crossing is c ontinuously measured and the influe nces of some critical factors, such as subgrade stiffne ss, maintenances (tampi ng) and weather, are investigated. The vibration test results show ground vibration mainly have influence in 20Hz-40Hz. This part needs to be filtered out to show rail displacement and quantitatively assess ballast condition. The measurement results after tamping indicate that rail displacements shortly increased and accelerations have no change related to tamping. It can be concluded that tamping will temporarily interrupt ballast states. In this case, tamping has no positive effect on the crossing performance. Weather influence is normally ignored, but the acceleration results show good correlation with daily temperature variation.