Dynamic load
Table of contents
E – 7 Design of reinforced concrete columns against impact load
Full title: An investigation of design procedures of reinforced concrete columns subjected to impact load according to codes and recent research work
* only in English *
Providing a reliable design approach for reinforced concrete (RC) columns against impact loading is crucial since impact causes disastrous consequences on structures and people’s lives. There are different scenarios of RC columns subjected to impact load, e.g., vehicle (truck, ship, etc.) collisions and rockfalls on bridge piers and building columns. RC columns are predominantly axially loaded members that resist the weight of superstructures and live loads. Therefore, a combination of simultaneous axial force and a lateral impact load should be considered for designing these members. There are various design codes all over the world that are the references for engineers to design new structures and retrofit old structures. In this work, a complete literature review on the design procedures of axially-loaded RC columns against impact load according to design codes and recent research work is to be conducted and at the end, a discussion-based comparison needs to be presented.
Subtasks:
- Literature review (including worldwide codes and research work) on design procedures of axially-loaded RC columns against impact load
- Presenting a comparative discussion on different design approaches based on design codes and research literature
Contact person:
Ghazaleh Taheri, M.Sc.
0351 463-37289
E – 6 Load capacity in case of impact
Full title: Impact on reinforced concrete structures – determination of load-bearing capacity and evaluation of experiments
The load-bearing capacity and resistance of reinforced concrete structures under impact loading have been investigated in a large number of research projects at the Institute of Concrete Structures. This research, for the exceptional load case of impact, is intended to validate and further develop the known calculation methods, as research questions are still unanswered in core topics due to the complex material and structural behavior.
As part of the work, the impact tests carried out in the drop tower at TU Dresden are to be evaluated and documented. The evaluated test results are then to be checked and analyzed using generally known engineering calculation methods. Both simplified static and complex dynamic calculation methods can be used.
The task will be concretized depending on the current test series and the interests of the student.
Contact person:
Thomas Schubert M.Sc.
0351 463-36912
E – 5 Numerical study on damping layers
Full title: Numerical investigation into the variation of the density and strength of a damping layer and its influence on energy absorption and force reduction
Experiments with different reinforced concrete components were carried out in the drop tower of the TU Dresden. A steel impactor with a velocity of up to 200 km/h hit a reinforced concrete component with and without reinforcement on the upper side, i.e., the side facing the impact. These reinforcement layers consist of a top layer to distribute the load and an underlying damping layer absorbing a large part of the impact's energy, thus protecting the underlying structural member. The material properties of the energy-absorbing layer are the investigation objective of this work. The density and strength of this layer are to be varied to find the material with the optimum properties. The optimization goal is to achieve the highest possible energy absorption while maintaining a low impact force.
The investigations will be carried out in the explicit finite element program LS-Dyna. Models of the old steel concrete component and the impactor will be provided. Furthermore, a material model for the surface layer will be available. The work aims to calibrate the damping layer's material model based on the available tests and the subsequent variation of the material properties.
Details of the task will be specified during the processing time.
Contact person:
Dr.-Ing. Lena Leicht
0351 463-33311
E – 3 Numerical study on shape of impactor and induced wave
Full title: Numerical investigation on the influence of the impactor shape on the waveform in split-Hopkinson bar experiments
The split-Hopkinson bar is a test device for dynamic material testing. A projectile (impactor) is accelerated via a gas pressure gun and generates a load wave which is introduced into the specimen via a long bar. The material and the geometry of the impactor determine the shape and length of the generated load wave.
Within the scope of the thesis, different impactor shapes shall be investigated numerically. By means of parameter studies, correlations between impactor shape and waveform are to be derived. The FEM software ANSYS is recommended. Promising impactor geometries can be fabricated and tested in experiments.
Details of the task will be specified during the processing time.
Contact person:
Thomas Schubert M.Sc.
0351 463-36912
E – 1 Plates under impact
The design of structures is usually carried out by drawing up a structural analysis. As the name implies, primarily static loads occur. In special cases, however, loads can also act dynamically on structures. The prediction of the load-bearing capacity, the vibration response and the damage that may occur are considerably more complex than in the static case.
The impact of a falling mass on reinforced concrete slabs and the derivation of a design model are currently the focus of a research project at the Institute of Concrete Structures. The aim of your thesis is to research existing models, to compare them and, if necessary, to verify them with actual test results.
The task will be concretized depending on the current test series and the interests of the students.
Contact person:
Dipl.-Ing. Nicholas Unger
0351 463-32005