Wyniki wyszukiwania - BazTech

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Thermoplastic fibre metal laminates: Stiffness properties and forming behaviour by means of deep drawing

Wollmann T., Hahn M., Wiedemann S., Zeiser A., Jaschinski J., Modler N., Ben Khalifa N., Meißen F., Paul C.

Archives of Civil and Mechanical Engineering

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2018

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Vol. 18, no. 2

442--450

EN

Hybrid materials provide a high potential for lighter structures and an improved crash performance. The investigated hybrid sandwich laminate consists of steel cover sheets and a carbon fibre-reinforced thermoplastic core. The first part of this investigation is focusing on an analytical prediction as well as on a comparison of numerical and experimental results for the evaluation of the laminate properties to get a general understanding for the material. Within the second part the forming behaviour of this material is investigated experimentally, analytically and numerically by means of cup deep drawing. These results indicate that cup deep drawing of thermoplastic fibre metal laminates is possible but limited. The limits in terms of achievable drawing depths are found to be defined by cracking and wrinkling of the cover sheets as well as fibre failure in the composite material.

2

Henkin semantics for reasoning with natural language

Hahn M., Richter F.

Journal of Language Modelling

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2015

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Vol. 3, No. 2

513--568

EN

The frequency of intensional and non-first-order definable operators in natural languages constitutes a challenge for automated reasoning with the kind of logical translations that are deemed adequate by formal semanticists. Whereas linguists employ expressive higher-order logics in their theories of meaning, the most successful logical reasoning strategies with natural language to date rely on sophisticated first-order theorem provers and model builders. In order to bridge the fundamental mathematical gap between linguistic theory and computational practice, we present a general translation from a higher-order logic frequently employed in the linguistics literature, two-sorted Type Theory, to first-order logic under Henkin semantics. We investigate alternative formulations of the translation, discuss their properties, and evaluate the availability of linguistically relevant inferences with standard theorem provers in a test suite of inference problems stated in English. The results of the experiment indicate that translation from higher-order logic to first-order logic under Henkin semantics is a promising strategy for automated reasoning with natural languages.

3

Test thresholds for assessment of possible groundwater contamination at sites contaminated with radioactive materials

Gellermann R., Hahn M., Haberlau U., Beetz J.

Prace Naukowe GIG. Górnictwo i Środowisko / Główny Instytut Górnictwa

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2004

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nr 1

77-78

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Methodology of deck machinery reliability analysis with respect to fatigue stress arising from ship's rolling

Hahn M.

Marine Technology Transactions. Technika Morska

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1999

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Vol. 10

117-130

EN

In the paper a new method of service conditions simulation and description of their influence on fatigue failure is presented. The fatigue degradation process due to ship's motion in waves and from machine working state as the basis for determination of reliability function of deck machinery elements are considered. The overloads of elements of complex technical systems which are the results of damage of other elements are taken into account.

PL

W pracy przedstawiono nową metodę symulacji warunków eksploatacji oraz opis wpływu tych warunków na uszkodzenia zmęczeniowe. Rozważa się proces degradacji zmęczeniowej wynikający z kołysań oraz stanu roboczego maszyny jako podstawę do określenia funkcji niezawodności elementów. Uwzględniono proces przeciążeń elementów złożonego systemu technicznego będących skutkiem uszkodzeń innych elementów tego systemu.