Dimension of interaction dynamics

A method allowing to distinguish interacting from non-interacting systems based on available time series is proposed and investigated. Some facts concerning generalized Renyi dimensions that form the basis of our method are proved. We show that one can find the dimension of the part of the attractor of the system connected with interaction between its parts. We use our method to distinguish interacting from non-interacting systems on the examples of logistic and H\'enon maps. A classification of all possible interaction schemes is given.Comment: 15 pages, 14 (36) figures, submitted to PR

Constraining 2HDM by Present and Future Muon(g-2) Data

Constraints on the general 2HDM ("Model II") are obtained from the existing $(g-2)_{\mu}$ data including limits on Higgs bosons masses from LEP I data. We consider separately two cases: with a light scalar $h$ and with a light pseudoscalar $A$, assuming ${M_{h}+M_{A}} \ge {M_{Z}}$. The charged Higgs contribution is also included. It is found that already the present $(g-2)_{\mu}$ data improve limits obtained recently by ALEPH collaboration on \tb for the mass of the pseudoscalar below \mr 2 GeV. The improvement in the accuracy by factor 20 in the forthcoming E821 experiment may lead to more stringent, than provided by ALEPH group, limits up to $M_A\sim$ 30 GeV if the mass difference between $h$ and $A$ is $\sim M_Z$. Similar results should hold for a light scalar scenario as well.Comment: 19 pages, including 5 figure

Wpływ temperatury przemiany bainitycznej na właściwości ochronne pancerzy pasywnych z wysokowęglowej nanostrukturalnej stali bainitycznej

The results of computer simulation of penetration of the 12.7 mm armour piercing incendiary (API) projectile of the B-32 type into layered armours are presented in this paper. The armours consisted of five variants of the bainitic steel plates (BSPs) with different mechanical properties, obtained as a result of the use of plastic-heat-treatment: bainitic transformation (BT) at different temperatures, rolling at room temperature, different tempering times. The bainitic steel plates of the size 50x50x10 mm were put on the armour steel „witness” plate (Armox 500) of the size 500x500x10 mm. The computer simulations were carried out with the use of the Ansys - Autodyn v12.1.0 program by means of the Lagrange method. Variations of the projectile velocity along the penetration axis of the layered armour (LA) were presented for each variant of the BSPs. After firing of the LA with this projectile the parameters describing deformation of the „witness” plate were compared with the computer simulation results. In case of plates subjected to the bainitic transformation (BT) at the temperatures of 200oC and 300oC the result of the computer simulation was similar to the result of the experimental test (respectively: stopping of the projectile, perforation of the BSP and the „witness” plate).W artykule przedstawiono wyniki symulacji komputerowej procesu penetracji pancerzy warstwowych 12,7 mm pociskiem przeciwpancerno-zapalającym (API) typu B-32. Pancerze te zawierały 5 wariantów płytek ze stali bainitycznych (BSPs) o różnych właściwościach wytrzymałościowych, uzyskanych w wyniku zastosowania obróbki cieplno-plastycznej: przemiana bainityczna (BT) w różnej temperaturze, walcowanie w temperaturze pokojowej, odpuszczanie w różnym czasie. Płytki ze stali baintycznych o wymiarach 50x50x10 mm umieszczone były na stalowej płycie pancernej „świadek” (Armox 500) o wymiarach 500x500x10 mm. Symulacje komputerowe wykonano za pomocą programu Autodyn v.12 z użyciem metody Lagrange'a. Dla każdego wariantu płytek bainitycznych przedstawiono przebieg zmian prędkości pocisku wzdłuż osi penetracji pancerza warstwowego (LA). Po ostrzale pancerza warstwowego tym pociskiem porównano parametry odkształcenia płyty świadek z wynikami symulacji komputerowych. W przypadku płytek poddawanych przemianie bainitycznej w 200oC oraz 300oC uzyskano wynik symulacji komputerowej zbliżony do wyniku badań eksperymentalnych (odpowiednio: zatrzymanie pocisku, perforację płytki bainitycznej i płyty świadek)

Numerical analysis of effectiveness for vehicle net systems protecting against shaped charge projectiles

W artykule przedstawiono analizę skuteczności dwóch typów systemów siatkowych chroniących pojazdy przed pociskami z głowicą kumulacyjną. Zbudowano modele numeryczne pocisku PG7-WM i systemów ekranów siatkowych, które użyto do wykonania symulacji penetracji ekranu przez pocisk. Za pomocą analiz numerycznych wyznaczono maksymalną odległość od osi pocisku na kierunku promieniowym, w której powinno dojść do kontaktu pocisku z elementami ekranów w celu jego neutralizacji. Wyznaczone odległości użyto do obliczenia prawdopodobieństwa neutralizacji pocisku przez systemy siatkowe. Obliczenia wykonano dla kątów elewacji i azymutu w zakresie α = 0÷45°. Wyliczone w taki sposób wartości posłużyły do sporządzenia wykresów przedstawiających zależności prawdopodobieństwa neutralizacji pocisku PG-7WM od rozmiaru oczka w przypadku obu typów systemów siatkowych oraz zależność prawdopodobieństwa neutralizacji pocisku PG-7WM od kątów elewacji i azymutu w przypadku różnych rozmiarów oczek obu typów systemów siatkowych. Wyniki mogą zostać wykorzystane do optymalizacji geometrii systemów siatkowych pod kątem efektywności neutralizacji pocisków.Analysis of effectiveness of two types of net systems protecting vehicles against projectiles with cumulative (shaped charge) warhead is presented in the article. Numerical models of net screens and PG7-WM projectile were created to simulate projectile penetration into the screen. Numerical analyses were used to determine a maximal distance in radial direction from projectile axis for which screen elements should come into contact with the projectile to neutralize it. Determined distances were used to calculate the probability of neutralization of projectiles by net systems. Calculations were performed for elevation and azimuth angles of α = 0÷45°. The values calculated in such way were used to make graphs of PG-7WM projectile neutralization probability for both types of net systems in function of mesh size and azimuth and elevation angles at various mesh sizes. Received results may be used to optimize geometries of net systems to increase effectiveness of projectile neutralization

Building and Validation of the Johnson-Cook Constitutive Model of Nano-Composite NANOS-BA® Steel for Armour Applications

Constitutive modeling of the NANOS-BA® steel is described in this article. Results of the experiments (quasi-static uniaxial tension and uniaxial compression, high strain rate compression with use of the Split Hopkinson Pressure Bar) are shown. On the basis of the experiments results, the values of constants of the Johnson-Cook (J-C) model for the NANOS-BA® steel were determined. Verification of the determined values of constants was described, in which the stresses and strains obtained in samples in experiments and simulations were compared. The additional verification of the determined parameter values was the comparison of the depth of penetration tests (DP tests) results of NANOS-BA® steel plates placed on the Armox 500T „witness” plate fired with a 12.7 mm B-32 projectile, obtained experimentally and in simulations. Small differences between simulation and the experiments results testify that the determined values of constants of J-C model for NANOS-BA® steel provide good agreement with experiments

Dodatkowy pancerz pasywny do ochrony pojazdów lekko-opancerzonych

The possibility of increasing of passive armour protection effectiveness by inclination of its surface in relation to the initial axis of the projectile trajectory was analyzed in this article. Phenomena which occur during penetration of the armour-piercing projectiles API into steel plates placed at different angles in relation to the initial axis of the projectile were described. Characteristic mechanisms of the API projectile behaviour observed during experiments, i.e. fragmentation of the projectile core during oblique perforation and deflecting of its trajectory from the initial axis of the penetration, were reproduced in the Ansys Autodyn v.14 computer program. On the basis of numerical analyses and results of experimental tests available in literature the layer of the armour was designer which contains perforated steel plates placed at the angle α=45º in relation to predicted projectile trajectory. Computer simulations of the 14.5 mm AP type B-32 projectile impact onto the model of the armour layer were made in the Ansys Autodyn v.14 program. The results obtained during the numerical analyses confirm that perforated steel plates placed at proper angle have high protection effectiveness against the API projectiles of the 4th level of STANAG 4569.W artykule przeanalizowano możliwość zwiększenia skuteczności ochronnej pancerza pasywnego w wyniku pochylenia jego powierzchni względem początkowej osi trajektorii lotu pocisku. Dokonano analizy zjawisk zachodzących podczas penetracji pocisków przeciwpancernych API (armour-piercing) w płyty stalowe umieszczone pod różnymi kątami. Zaobserwowane podczas badań eksperymentalnych charakterystyczne mechanizmy powstrzymywania pocisków API (kruszenie rdzenia pocisku przy perforacji kątowej, odchylanie jego toru lotu od początkowej osi penetracji) odwzorowano numerycznie w programie Ansys Autodyn v. 14. Następnie, na podstawie analiz numerycznych oraz dostępnych w literaturze wyników eksperymentalnych, zaprojektowano warstwę pancerza, wykorzystującą perforowane blachy stalowe umieszczone pod kątem 45º w stosunku do przewidywanego toru lotu pocisku. W programie Ansys Autodyn v. 14 wykonano symulacje komputerowe uderzenia 14,5 mm pocisku API typu B-32 w zaprojektowaną warstwę pancerza. Uzyskane podczas analiz numerycznych wyniki mogą świadczyć o tym, że stalowe płyty perforowane umieszczone pod odpowiednim kątem względem uderzającego pocisku, mają wysoką skuteczność ochronną przeciw pociskom AP na poziomie 4 wg STANAG 4569

Building and Validation of Numerical Models of the B-32 Type Armour-Piercing Projectiles

Process of building and the validation of the numerical models of the B-32 type armour-piercing incendiary (API) projectile is described in this article. Results of projectile compression tests (static and under high strain rates with the use of the modified Split Hopkinson Pressure Bar) are shown. On the basis of this, the values of the Johnson–Cook (J–C) strength model parameters for the projectile core material (N12e steel) were determined. This article presents results gained from simulations of the tests, in which the B-32 type projectile was modelled with the use of determined values of the J–C strength and failure models parameters. The process of the parameters values verification was described, in which the stress and strain obtained from samples in experiments and simulations were compared. Additional verification of the determined parameters values was comparison to the depth of penetration (DP) tests results of the Armox 500T plates fired with the 12.7 mm B-32 type projectile, obtained experimentally and in simulations. Small differences (< 5%) between stress and penetration depths obtained in the simulations and in the tests showed that the J–C parameter values were determined correctly

Numerical-Experimental Evaluation of the Armour Protection Capabilities

This paper presents a numerical and experimental study of a composite add-on armour panel used for protection of lightweight armoured vehicles impacted by the 7.62 mm API (Armour Piercing Incendiary) BZ projectile (2nd level of International Agreement STANAG 4569). The composite armour consists of a number of ceramic tiles supported by one layer of aramid fabric placed inside an aluminium casing. The problem of the impact of the projectile onto the composite armour has been solved in three-dimension space (3D) with the use of CAD and CAE methods implemented in Ansys Autodyn v15 software. On the basis of the results of computer simulations, the proportions of the thickness of the armour layers were chosen. After that, the real model of the composite armour was built and tested in the firing range. The results obtained in the simulations were compared with the depth of penetration (DP) tests results, and satisfying agreement was obtained

Numerical-Experimental Analysis of Applicability of NANOS-BA Steel for Armour

Described in this paper is the analysis of the applicability of NANOS-BA steel for armour. The results of depth of penetration (DP) tests of the NANOS-BA steel plates placed on the Armox 600T „witness” plate and fired at with the 12.7 mm B-32 type projectile are shown. These results are compared to the Al2O3 ceramic plate penetration with the use of the same method. In both cases the armour was of similar area density (approx. 39 kg/m2). The theoretical analysis of the applicability of the NANOS-BA steel in a layered armour was conducted and numerical simulations of the DP tests were performed. Additional simulations were made for two variants of layered armour penetration: in variant 1 - One of the layers in construction was of the NANOS-BA steel, in variant 2 - One of the layers was of special ceramics. The process of the simulations verification is described, in which the deformations of the „witness” plate obtained experimentally are compared to the results of the simulations. Small differences (< 2 mm) of penetration were obtained in the simulations and experimentally confirmed that the simulations were performed correctly

A method for analysing ram pressure characteristics of impeller pump rotor

This paper presents a method in which typical tests of centrifugal pump are used to obtain information on real value of discharge angle of flow leaving the rotor. The method can be applied to properly choose inlet angle to blade palisade of centrifugal guide vanes in the case when to perform measurements of velocity fields behind the rotor more precisely is not possible