JB Jens Burgert

Dr.-Ing. Jens Burgert

  • Institut für Technische Mechanik
    Teilinstitut Dynamik/Mechatronik
    Geb. 10.23, 2.OG
    Kaiserstraße 10
    76131 Karlsruhe

Curriculum vitae

since 01/2021 PostDoc, Research assistant
at Institute of Engineering Mechanics of the KIT
03/2016 – 12/2020 Research assistant
at Institute of Engineering Mechanics of the KIT

Dissertation: On direct and inverse problems related to longitudinal impact of non-uniform elastic rods
Research stay over several weeks at the Angström Laboratory, Uppsala, Sweden and at the Technical University Tampere, Finland
01/2016 – 02/2016 Englisch teacher AIES International, Vietnam
04/2013 – 10/2015 Mechanical Engineering study
at Karlsruhe Institute of Technology

Majoring in: Theoretical Mechanical Engineering
Main focus: Dynamic and vibrations and cognitive technical systems
Degree: Master of Science with distinction
Master thesis:  Model-based development of a systematic approach to optimize electrical drive systems with variable operation voltage
09/2013 – 05/2014 Study abroad at
Heriot-Watt University Edinburgh, Scotland
04/2013 – 08/2013  Student employee
at Robert-Bosch GmbH, Bühlertal

Setup of a parametric tailgate model using ADAMS
10/2009 – 03/2013 Mechanical Engineering study
at Karlsruhe Institute of Technology

Main focus: Dimensioning and validation of mechanical constructions
Degree: Bachelor of Science
Bachelor thesis:  Implementation of the thermo-mechanical load on a clutch pressure plate: main focus thermal calculation
10/2012 – 03/2013 PreMaster
at Robert-Bosch GmbH, Bühl

Noise examination and modeling of an electrical low power motor

Research interests

Stress wave optimization of impacting rods
Bild
(a) Experimental setup and (b) schematic sketch of the experimental setup
Hit Jens Burgert
Discontinuous movement of the rod after impacted by the piston, recorded with a high-speed camera

Impacting rods are used in various devices in practical life. One example is rock drilling, where a piston is accelerated hydraulically or pneumatically before it hits the drill rod. The hit is followed by a complicated sequence of phenomena. A stress wave, whose length is double the physical length of the piston, starts to propagate along the drill rod to finally reach the tool-process material interface. A nonlinear penetration of the bit into the rock takes place and a reflecting wave component is generated.

In the long history of rock drilling, fundamental mechanisms contributing to the effective drilling process are still unknown. To produce maximal tool penetration for each hit, rules have to be derived which specify the dimensioning of the piston and drill rod. Recent investigations, that cover the issue of optimization, are revealing that the efficiency of the drilling process strongly depends on the shape of the longitudinal wave transmitted through the drill rod to the drill bit. A well-known fact is that the cross-sectional profile of the piston is shaping the stress wave profile. Therefore, the main object of the research project is to adjust the geometrical form of the impacting piston to generate every desired stress wave form. This is an inverse problem as the cause (geometry of the piston) is concluded from the consequence (stress wave form after impact). For inverse problems, it needs to be examined if a solution exists and if the solution is unique.

A test rig is set up in order to validate the theoretical results. The stress wave from is derived from the strain gauges (SG) signal which is further processed with a signal conditioner. By recording the hit with a high-speed camera, the time when piston and rod separate may be detected. Besides, the high-speed camera is able to validate the theoretical calculations which predict that the rod moves discontinuously after the hit.

Monograph


Publications


2019
Measuring the wave shape and wave propagation speed of two impacting rods of arbitrary cross section and material.
Burgert, J.; Seemann, W.
2019. 26th International Congress on Sound and Vibration 2019 (ICSV26), Montreal, Canada, 7 - 11 July 2019, 199–206, Curran Associates, Inc 
2018
Pneumatic single hit test rig for analysis of the stress wave profile of non-uniform impacting rods.
Burgert, J.; Seemann, W.; Moilanen, C.; Montonen, J.; Miettinen, J.; Saarenrinne, P.
2018. Proceedings of ISMA2018, International Conference on Noise and Vibration Engineering/USD2018, International Conference on Uncertainty in Structural Dynamics : Leuven, Belgium, 17 - 19 September, 2018. Ed.: W. Desmet, 3535–3547, KU Leuven 
2017
Optimization of the piston geometry to generate a desired stress wave shape.
Burgert, J.; Seemann, W.; Hartenbach, F.
2017. Proceedings in applied mathematics and mechanics, 17 (1, SI), 675–676. doi:10.1002/pamm.201710306

Teaching

Betreute Lehrveranstaltungen

WS 21/22
SS 2021
SS 2020
WS 19/20
SS 19
WS 18/19
SS 18
SS 18
WS 17/18
SS 17
SS 17
WS 16/17
WS 16/17
SS 2016
SS 2016