Purpose: The purpose of the current study was to develop and validate a finite element (FE) pedestrian model with high computational efficiency and stability using a novel modeling approach. Methods: Firstly, a novel modeling approach of using hollow structures (HS) to simulate the mechanical properties of soft tissues under impact loading was proposed and evaluated. Then, an FE pedestrian model was developed, employing this modeling approach based on the Total Human Model for Safety (THUMS) pedestrian model, named as THUMS-HS model. Finally, the biofidelity of the THUMS-HS model was validated against cadaver test data at both segment and full-body level. Results: The results show that the proposed hollow structures can simulate the mechanical properties of soft tissues and the predictions of the THUMS-HS model show good agreement with the cadaver test data under impact loading. Simulations also prove that the THUMS-HS model has high computational efficiency and stability. Conclusions: The proposed modeling approach of using hollow structures to simulate the mechanical properties of soft tissues is plausible and the THUMS-HS model could be used as a valid, efficient and robust numerical tool for analysis of pedestrian safety in vehicle collisions.
Disc brakes in passenger cars are extremely important due to safety concerns. Their operational quality largely rests on the conditions of contact between the working elements, which mainly consists offlat and dry sliding. The tribological phenomena thatoccur during braking are, unfortunately, extremely complex and difficult to recreate in laboratory settings. Many scientific institutes conduct research to improve our understanding of these phenomena. The results they present make it possible to continuously simplify the procedures for selecting friction materials and reducing the costs of identifying the properties of new products. This article analyses the methods commonly used by researchers. It also presents different set-ups of research stations, as well as the advantages and drawbacks of each method.
A line start permanent magnet synchronous motor (LSPMSM) supplied with distorted voltage is analysed. The study is based on the field–circuit model. The algorithm for solving the equations of the model is discussed. In the analysis of the selected states of the motor the non–linearity of the magnetic circuit and skewed slots of the rotor are taken into consideration. In order to verify the developed algorithm and software, among others the startup process of the motor has been examined. The electromagnetic torque and phase currents are calculated. The results of computations have been compared to the results obtained using the commercial FEM package Comsol Multiphisics. Selected results of simulation tests are shown.
4
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
The paper presents a special algorithm and software for the analysis of coupled electromagnetic-thermal phenomena in a squirrel cage induction motor. In the proposed model the nonlinearity of the magnetic circuit, the movement of the rotor, the skewed slots and the influence of temperature on electrical and thermal properties of the materials have been taken into account. In order to verify the developed algorithm and software, the startup process of the motor has been examined, among others. The results of computations have been compared to the measurements.
PL
W artykule przedstawiono opracowany przez autora algorytm i oprogramowanie do analizy sprzężonych zjawisk elektromagnetycznych i cieplnych w silniku indukcyjnym klatkowym, Sg 100L-4B o mocy 3 kW. W opracowanym modelu zjawisk uwzględniono nieliniowość obwodu magnetycznego, ruch wirnika, skoszenie żłobków oraz wpływ temperatury na właściwości elektryczne i termiczne materiałów. W celu weryfikacji opracowanego algorytmu i oprogramowania przeprowadzono badania laboratoryjne. Przeprowadzono rozruch silnika indukcyjnego obciążonego momentem wynoszącym 12 Nm.
W pracy przeprowadzono teoretyczne badania nad procesem walcowania kęsów we wstępnej grupie klatek walcowni ciągłej. Problematyka pracy dotyczy optymalizacji walcowania stalowych kęsów otrzymywanych w procesie ciągłego odlewania w taki sposób, aby występujące wady powierzchniowe mogły zostać zawalcowane lub nie powstawały podczas walcowania w wstępnej grupie klatek. Do badań teoretycznych procesu walcowania zastosowano program komputerowy Forge2008®, który oparty jest na metodzie elementów skończonych i pozwala na termomechaniczną symulację procesów walcowania w trójosiowym stanie odkształcenia. Przeprowadzone numeryczne modelowanie walcowania pozwoliło na optymalny dobór kształtu wykrojów i odkształceń w pierwszy sześciu przepustach.
EN
In this work was carried out theoretical investigations on the process of billets rolling in the initial group of stands on continuous rolling mill. The main issue of this work concerns to optimizing the rolling of steel billets obtained by continuous casting process in such a way that the occurring surface defects can be eliminated or not formed during rolling in the initial group of stands. The computer program Forge2008®, which is based on the FE method and allows thermo mechanical 3D analysis of the rolling process, was used. Performed numerical modelling of rolling allowed for optimal selection the rolling pass shapes and strains in the first six passages.
6
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
A new universal 40 t deck crane for bulk carriers was constructed by the Towimor S.A., Toruń, the main Polish supplier of deck cranes and deck machinery [1]. Strain gauge measurements of the crane were performed during the stands tests at the factory. After the tests a finite element analysis of the crane was carried out to provide additinal detail information for checking accuracy of the numerical modelling in view of improving the applied FE model. In this study application of the FE method played a role independent of the experiments. Comparision of the results obtained from the two methods made it possible to improve the FE model and support the experimental results.
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.