The paper deals with a new uniform crashworthiness concept of car bodies optimization of high-speed trains. The design optimization was done from the point of view of structural protection of occupants' survival space. For the reason that it is impossible to find a highly probable scenario for the derailment, the authors decided to find the solution in the form of rigid frame structure (survival cells), which will provide safety space for the passengers.In the optimization example a typical passenger car body was divided into cells of approximately equal dimensions. The optimization problem was to minimize the mass of the structure with stress constraints. The survival cell was subjected to a sequence of high value loads. The loads are acting in an asynchronous way in three load directions what gives the optimized structure uniform crashworthiness.The optimization strategy consists of three stages. In the first step, the constant criterion surface algorithm (CCSA) of topology optimization is applied to find a preliminary solutions. For improving the manufacture properties of this solution, a new concept of design space constraints was proposed. The sizing optimization with evolutionary algorithms was used to define a thin-walled structure in the second step. For evolutionary optimization a standard procedure was employed. Finally, CCSA optimization algorithm was This paper was presented in the 9th World Congress on Structural and Multidisciplinary Optimization, International Society for Structural and Multidisciplinary Optimization, Shizuoka, Japan, 2011 M. Mrzygłód · T. Kuczek ( ) Institute of Rail Vehicles, Cracow University of Technology, al. Jana Pawła II 37, Kraków, M. Mrzygłód e-mail: mrzyglod@mech.pk.edu.pl applied again to remove excessive material from a car body structure. As the optimization result a new design proposition of a car body with multiple survival cells of high uniform stiffness was obtained. By maintaining passengers' survival space, the passive safety of a high-speed car body was significantly increased.
A high resolution neutron spectrometer (HRNS) system has been designed as a neutron diagnostic tool for ITER. The HRNS is dedicated to measurements of time resolved neutron energy spectra for both deuterium and deuterium-tritium (DT) plasmas. The main function of the HRNS is to determine the fuel ion ratio n t /n d in the plasma core with 20% uncertainty and a time resolution of 100 ms for a range of ITER operating scenarios from 0.5 MW to 500 MW in fusion power. Moreover, neutron spectroscopy measurements should also be possible in the initial deuterium phase of ITER experiments. A supplementary function of the HRNS is to provide information on the fuel ion temperature. Furthermore, the HRNS can be used as an additional line-of-sight (LOS) for the radial neutron camera. To meet these requirements, a set of four spectrometers positioned after each other along a single LOS has been designed. The detector techniques employed include a thin foil proton recoil spectrometer (TPR), a neutron diamond detector (NDD), a back-scattering time-of-flight system (bToF) and a forward timeof-flight system (fToF). The TPR system, positioned closest to the plasma, provides data at high fusion powers. For plasma conditions producing intermediate fusion power two neutron spectrometers are installed: NDD and bToF. The NDD is installed as the second instrument along the HRNS LOS after the TPR. The fToF spectrometer is dedicated for low tritium densities and pure deuterium operation.The paper summarizes the current state of the art of neutron spectroscopy useful in plasma diagnostics and the possibility of installing a dedicated HRNS for ITER in the designated diagnostic port. We conclude that the proposed HRNS system can fulfil the ITER
Abstract. This paper sets out to describe a multi-constrained approach to topology optimization of structures. In the optimization, a constant criterion surface algorithm and the multi-constraint procedure is used. The multi-constraint procedure consists of constraints normalization and equivalent design space assembling. The work is illustrated by an example of the L-shaped domain optimization with the horizontal line support and complex loads. The example takes into consideration stress, fatigue and compliance constraints. The separate and simultaneous application of constraints resulted in significant differences in structure topology layouts. The application of a fatigue constraint gave more conservative results when compared to static stress or compliance limitations. The multi-constrained approach allowed effectively lowering the mass of the structure while satisfying all constraints.
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