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Modeling of the axial crumpling of conical shells

Riyah N. Kiter Mazin Y. Abbood Omar H. Hassoon

Archive of Mechanical Engineering | 2022 | vol. 69 | No 4 | 615-628 | DOI: 10.24425/ame.2022.143096

Keywords axial crushing concertina eccentricity ABAQUS inward folding

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Abstract

The axial crumpling of frusta in the axisymmetric "concertina" mode is examined. A new theoretical model is developed in which the inward folding in both cylinders and frusta is addressed. The results were compared with previous relevant models as well as experimental findings. The flexibility of the model was substantiated by its capability of describing and estimating the inward folding in frusta in general as well as in cylinders as a special case. A declining trend of the eccentricity dependence with the D/t ratio was found in contrast with a previous theory which suggests total independency. ABAQUS 14-2 finite element software was employed to simulate the thin tube as a 3-D thin shell part. Numerical simulations of the process were found to, firstly, underestimate the theoretical values of inward folding in general, secondly anticipate more underestimations as the tubes become thinner and/or have larger apex angle, and finally anticipate as low as 300 apical angle frusta to revert its mode of deformation to global inversion.

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Bibliography

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Authors and Affiliations

Riyah N. Kiter

1

Mazin Y. Abbood

1

e-mail:

ORCID:

Omar H. Hassoon

2

e-mail:

ORCID:

Department of Mechanical Engineering, College of Engineering, University of Anbar, Iraq
Department of Production and Metallurgy Engineering, University of Technology, Baghdad, Iraq

Palaeomagnetism of metacarbonates and fracture fills of Kongsfjorden islands (western Spitsbergen): Towards a better understanding of late- to post-Caledonian tectonic rotations

Krzysztof Michalski

Polish Polar Research | 2018 | vol. 39 | No 1 | 51-75

Keywords Arctic Svalbard metamorphic Caledonian basement Eurekan deformations West Spitsbergen Thrust and Fold Belt palaeomagnetism

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Abstract

A total number of 156 palaeomagnetic specimens of metacarbonates from 9 sites in Blomstrandhalvøya and Lovénøyane (Kongsfjorden, western Spitsbergen) and an additional 77 specimens of unmetamorphosed sediments infilling fractures (4 sites) within the Caledonian metamorphic basement of Blomstrandhalvøya were demagnetized. No relicts of pre-metamorphic magnetization were identified. The Natural Remanent Magnetization (NRM) pattern of metacarbonates is dominated by Caledonian (sensu lato) – Svalbardian and Late Mesozoic/Cenozoic secondary magnetic overprints carried by the pyrrhotite and magnetite/maghemite phases, respectively. The NRM of unmetamorphosed sediments infilling the karstic/tectonic fractures is dominated by hematite carrier. It revealed three stages of magnetization: Caledonian sensu lato, Carboniferous and Late Mesozoic/Cenozoic, which can be related to their initial fracturing, karstification and sedimentation or reactivation. As the majority of the palaeopoles calculated for the Kongsfjorden sites fit the 430 – 0 Ma sector of Laurussia reference path in an in situ orientation these results support the hypothesis that Blomstrandhalvøya and Lovénøyane escaped main Eurekan deformations. The potential rotation of the Kongsfjorden basement by any west dipping listric fault activity rotating the succession accompanying the opening of North Atlantic Ocean was not documented by the palaeomagnetic data presented here.

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Krzysztof Michalski

New palaeomagnetic data from metamorphosed carbonates of Western Oscar II Land, Western Spitsbergen

Krzysztof Michalski Justyna Domańska-Siuda Krzysztof Nejbert Geoffrey Manby

Polish Polar Research | 2014 | No 4 | 553-592 | DOI: 10.2478/popore−2014−0031

Keywords Arctic Spitsbergen Caledonides West Spitsbergen Fold Belt palaeo−magnetism petrography metacarbonates metamorphic pyrrhotite ferromagnetic carriers

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Abstract

Palaeomagnetic−petrographic−structural analyses of Proterozoic–Lower Palaeozoic metamorphosed carbonates from 12 locations within Oscar II Land (Western Spitsbergen) have been carried out to determine their usefulness in palaeogeographic reconstructions for Caledonian time. Structural analyses confirm that metacarbonates record several stages of deformation: D1, D2 ductile phases related to Caledonian metamorphism and a D3 brittle phase related to Late Cretaceous–Paleogene evolution of the West Spitsbergen Fold Belt. The latter is represented by thrust faults, localized folds with strain slip cleavages and late extensional collapse. Petrographic investigations reveal that Caledonian greenschist facies metamorphism was characterized by the high activity of H 2 O−CO 2 −rich fluids which promoted extensive recrystallization and within−rock spatial reorganization of sampled meta carbonates. Microscopic, SEM and microprobe analyses exclude the existence of any primary pre−metamorphic ferromagnetic minerals (primary−related to sedimentation and or early diagenesis) and point to metamorphic 4C superstructure (Fe 7 S 8 ) pyrrhotite as the main ferromagnetic carrier in investigated rocks. This is confirmed by the three−component isothermal remanent magnetization (IRM) procedures and the results of thermal demagnetizations. In 12 sites a total number of 72 independently oriented palaeomagnetic samples were collected from which 181 specimens were drilled and thermally demagnetized. Sampled metacarbonates are weakly magnetized (NRM <0.2mA/m). The statistically significant palaeomagnetic results were achieved only from 1 of 12 investigated sites. In one site situated in the Western overturned limb of the Holmesletfjellet Syncline intermediate unblocking temperatures – “pyrrhotite related” component WTSJ5M superimposed on the S1 Caledonian schistosity was recognized (D = 100.7 ° , I = −21.4 °a 95% = 5.5 ° , k = 58.23). Coincidence of WTSJ5M with Silurian–Devonian sector of the Baltica reference path after unfolding of the syncline by the angle of 130 ° suggests synfolding origin of this direction. Further, this suggests that Holmesletfjellet Syncline originated as an open fold and has been transformed into an overturned syncline during the Late Caledonian shortening or in the Late Cretaceous–Palaeogene time.

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Authors and Affiliations

1

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ORCID:

Kunyun Tian

1

e-mail:

ORCID:

Ruilin Zhang

1

e-mail:

ORCID:

Xing Xu

1

e-mail:

ORCID:

Wenyong Zhang

1

e-mail:

ORCID:

Juan Luo

1

e-mail:

ORCID:

Qing Yuan

1

e-mail:

ORCID:

School of Resource and Safety Engineering, Henan University of Engineering, Zhengzhou 451191, China

The Use of Structural Glass in Shaping Glazed Facades

Anna Jóźwik

Teka Komisji Urbanistyki i Architektury Oddziału Polskiej Akademii Nauk w Krakowie | 2023 | vol. LI | 359-384 | DOI: 10.24425/tkuia.2023.148983

Keywords structural glass glass facades frameless glass systems glass fins glass folded plate systems bent glass

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Abstract

Glass is a significant material in shaping contemporary architecture. Its main feature is transparency, which is related to the possibility of letting daylight into building interiors. Glass facades mark the almost invisible border between the interior and exterior space, which is a source of endless design inspiration. This situation is facilitated by the development of technology and knowledge on glass as a structural material.
The article aims to identify and analyse the possibility to apply structural glass in glazed facades. The paper analyses the technological and structural aspects of glass. The conducted analyses were based on the following methods: logical argumentation, comparative method, and case study. The analysis of selected architectural implementations provided a major contribution to the work results. Based on this, the typology and characteristics of design solutions were established for glass facades in which structural glass is used. The search for solutions aimed at shaping all-glass self-supporting structures was assumed as the main criterion of the indicated typology. It has been established that shaping all-glass self-supporting structures is achievable with the use of frameless systems, glass fins, folded plate glass systems, or facades with bent glass. By designing self-supporting systems, the elimination or reduction of support systems of other materials can be achieved. Thus, the use of structural glass in these structures allows for uniform material solutions. These solutions not only focus on technological and structural aspects but also have a significant impact on the architectural creation of the facade.

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Anna Jóźwik

1

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Warsaw University of Technology Faculty of Architecture

The Problem of Aliasing and Folding Effects in Spectrum of Sampled Signals in View of Information Theory

Andrzej Borys

International Journal of Electronics and Telecommunications | 2022 | vol. 68 | No 2 | 315-322 | DOI: 10.24425/ijet.2022.139884

Keywords signal sampling modeling of sampled signal in the time domain signal information content spectrum aliasing and folding Banach–Tarski-like paradox in signal sampling

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Abstract

In this paper, the problem of aliasing and folding effects in spectrum of sampled signals in view of Information Theory is discussed. To this end, the information content of deterministic continuous time signals, which are continuous functions, is formulated first. Then, this notion is extended to the sampled versions of these signals. In connection with it, new signal objects that are partly functions but partly not are introduced. It is shown that they allow to interpret correctly what the Whittaker– Shannon reconstruction formula in fact does. With help of this tool, the spectrum of the sampled signal is correctly calculated. The result achieved demonstrates that no aliasing and folding effects occur in the latter. Finally, it is shown that a Banach–Tarski-like paradox can be observed on the occasion of signal sampling.

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Andrzej Borys

1

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Department of Marine Telecommunications, Faculty of Electrical Engineering, Gdynia Maritime University, Gdynia, Poland

Neogene activity of the Outer Carpathians recorded by thrust-top basin deposits – an example from the Rzeszów area, Poland

Joanna Uroda

Acta Geologica Polonica | 2020 | vol. 70 | No 1 | 79-96 | DOI: 10.24425/agp.2019.126461

Keywords Skole thrust sheet Foreland and hinterland thrusts Outer Carpathian fold-andthrust belt Basin inversion depocentre migration syntectonic sedimentation

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Abstract

The Rzeszów thrust-top basin was formed on the active Skole thrust sheet of the Outer Carpathian fold-andthrust belt and filled with Miocene syntectonic sediments. New seismic 3D, well and field data were used to define the relationship between sedimentation and tectonic activity and to establish the synkinematic context of the Rzeszów basin-fill architecture. The basin evolution was controlled by the activity of the Carpathian frontal thrust and hinterland thrusts developed in the forelimbs of folds in the Skole thrust sheet, bounding the basin from the north and south, respectively. The activity of the frontal thrust resulted in hinterland-directed depocentre migration and tilting of the syntectonic stratigraphic sequence. Balanced cross-sections have indicated that during the last compressive stage of deformation, the syntectonic deposits filling the basin were shortened by c. 5%, which resulted in the formation of folds and contractional faults. The architecture of the syntectonic deposits and the development of contractional structures reflect the activity of thrusts bounding the basin during compressive deformation of the Carpathian orogenic belt.

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Authors and Affiliations

Joanna Uroda

Fluid pathways within shallow-generated damage zones of strike-slip faults – evidence of map-scale faulting in a continental environment, SW Permo-Mesozoic cover of the Late Palaeozoic Holy Cross Mountains Fold Belt, Poland

Barbara Rybak-Ostrowska Andrzej Konon Vratislav Hurai Maciej Bojanowski Agnieszka Konon Michał Wyglądała

Acta Geologica Polonica | 2020 | vol. 70 | No 1 | 1-29 | DOI: 10.24425/agp.2019.126454

Keywords Strike-slip faulting Fluid pathways Continental environment Chmielnik releasing stepover Permo-Mesozoic cover Holy Cross Mountains Fold Belt

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Abstract

The damage zones of exhumed strike-slip faults dissecting Jurassic carbonates in the south-western part of the Late Palaeozoic Holy Cross Mountains Fold Belt reveal second-order faults and fractures infilled with syntectonic calcite. The subsequent development of a structural pattern of microscopic fault-related structures and calcite infillings reflects the activity of strike-slip faults that began in the Late Cretaceous (Late Maastrichtian) and lasted until the early Miocene (Langhian). The fabric of the syntectonic veins provides insights into the evolution of the permeable fault-related structures that were the main pathways for fluid flow during fault activity. Microstructural study of calcite veins coupled with stable isotope and fluid inclusion data indicates that calcite precipitated primarily in a rock-buffered system related to strike-slip fault movement, and secondarily in a partly open system related to the local activity of the releasing Chmielnik stepover or the uplift of the area. The presence of meteoric fluids descending from the surface into damage zones suggest that the strike-slip faulting might have taken place in a nonmarine, continental environment.

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Authors and Affiliations

Barbara Rybak-Ostrowska

Andrzej Konon

Vratislav Hurai

Maciej Bojanowski

Agnieszka Konon

Michał Wyglądała

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Modeling of the axial crumpling of conical shells

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Bibliography

Authors and Affiliations

Palaeomagnetism of metacarbonates and fracture fills of Kongsfjorden islands (western Spitsbergen): Towards a better understanding of late- to post-Caledonian tectonic rotations

Abstract

Authors and Affiliations

New palaeomagnetic data from metamorphosed carbonates of Western Oscar II Land, Western Spitsbergen

Abstract

Authors and Affiliations

Spectrum Aliasing Does Occur Only in Case of Non-ideal Signal Sampling

Abstract

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Spectrum Aliasing Does not Occur in Case of Ideal Signal Sampling

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Another Proof of Ambiguity of the Formula Describing Aliasing and Folding Effects in Spectrum of Sampled Signal

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A Dual-Band Compact Integrated Rectenna for Implantable Medical Devices

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Controlling effect of palaeo-tectonic stress field on gas occurrence

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The Use of Structural Glass in Shaping Glazed Facades

Abstract

Authors and Affiliations

The Problem of Aliasing and Folding Effects in Spectrum of Sampled Signals in View of Information Theory

Abstract

Authors and Affiliations

Neogene activity of the Outer Carpathians recorded by thrust-top basin deposits – an example from the Rzeszów area, Poland

Abstract

Authors and Affiliations

Fluid pathways within shallow-generated damage zones of strike-slip faults – evidence of map-scale faulting in a continental environment, SW Permo-Mesozoic cover of the Late Palaeozoic Holy Cross Mountains Fold Belt, Poland

Abstract

Authors and Affiliations